In referring briefly to some of the circumstances affecting the manufacture of butter, the influence of the breed of the cow is worthy of notice. The Channel islander has large milk globules of a pretty uniform size and with a very delicate covering, thus indicating easy churning and a strong and unbroken grain in the butter. Devons come next in this important particular, then the old Holderness; while the Ayrshire, Shorthorn, and Dutch cows have smaller and more unequal globules, and covered with a much tougher membranous material. It is readily seen that in the milk of the latter breeds, churning will be prolonged, and that some of the butter enveloped in the smaller globules will never be obtained at all. In an experiment made by Dr Sturtevant with the milk of two Jersey and two Ayrshire cows, the globules of the former averaged in the one cow's milk 1/5680, in the other 1/5940 of an inch; those of the latter 1/4666 and 1/6000, showing that there was not a great difference in the size either in the milk of cows of the different breeds or in different animals of either breed. The cream from the Ayrshires took 20 and 25 minutes respectively to churn, that of the Jerseys only 3 and 8 minutes; thus proving that the pellicle of the butter globule of the latter was in churning much easier broken. The Ayrshires from new milk only gave part of the butter at 15 minutes and the rest at the end of 10 minutes longer; thus showing the inequality as to size and the toughness of the membrane; while the Jerseys, from milk everyway the same, gave butter in 5, and churning ceased at 8 minutes.

The health of the cow, also seriously affects the milk and consequently the butter. When a feverish condition—often unnoticed—is in the cow produced by fast-driving, annoyance, or worry, or even by exposure to a hot sun, and also by her being stinted of food or water, or, if though plentiful, they are of bad quality; the constituents of the milk, as found by analysis, are much altered. In milk rendered abnormal through being subjected to the influences referred to, the casein and albuminoids are almost doubled, the butter reduced by a half, and the sugar to rather less than a third of what they would have been with the cow in a normal state.

Butter Fats.

The fats of which butter is composed are four in number: the hardest is stearine—a white, flaky fat; the next in consistency is palmatine, resembling palm oil, and giving most of the colouring matter; the third, oleine—thin and oily; and the fourth consists of essential oils, probably as numerous as the varieties of food. All are derived from the food of the cow; but how much is directly derived from it, and how much elaborated out of the other elements of the food, is not well ascertained. No doubt, their characteristics change with the constitutional peculiarities of the cow and the condition and quality of her food; and, in the same animal, they change with the various degrees of age and succulence of the food and the abundance of the fats in it. Young food gives a higher colour and aroma than that approaching maturity; but permanent pastures and those of older rotation have these properties in inverse ratio to the age. The specific gravity of these fats in combination is 983 to 1000 for water; when separate no standard has for any of them been fixed. The essential oils are, of course, lighter than the solid fats, and these vary much—stearine, palmatine, and oleine being heavier in this order, although it has been known to be reversed. Besides the fats and oils enclosed in the globules, milk contains other volatile oils loosely mingled with it, and not in combination with any constituent, so much so, that they escape immediately on exposure to the air or the raising of the temperature.

Animal Odour.

Animal odour is a flavour intrinsically belonging, to some extent, to the milk itself, for it is present in greater proportion when the milk is newly drawn. If not dissipated by exposure to the air, it affects not only the milk but all the products manufactured from it. It is best known as the peculiar flavour of new milk, which prevents, with some individuals, its use at an early stage. In some adults it produces nausea and disturbs health; but it is relished by, and is altogether innocuous to, children. This odour is peculiar to the milk of all mammalia, and has a powerful influence on it, so much so, that there is a very great difference between that in which it exists and that from which it is expelled. It resembles the mingled breath and perspiration of the cow, is in a greater degree attached to milk newly drawn, and is spoken of as a "cowy" odour. It is to the factory managers of America we are greatly indebted for a better knowledge and management of this enemy, for previous to their origin, even yet in this country, it has not attracted sufficient attention. But the increased supply of milk now required for the large towns, and the urgent demand for a better article in milk, cheese, and butter, have in late years led to a better idea of its nature and the means to be employed for its dissipation. The influence of animal odour on butter is, without doubt, deleterious; for if it be, by cooling the new milk too low or too suddenly, carried into the cream and thence into the butter, a bad flavour is the result. The fine, aromatic, delicious taste of the oleine and its essential oils is replaced by a strong indistinct flavour betraying the presence of some impurity, and the former—the one natural to the butter—becomes so modified and obscured as to be indistinguishable; consequently, such butter is said to be "off flavour." This odour escapes rapidly with an increase, slowly with a decrease of temperature; when very low it fails to escape and remains permanently in the milk. If milk is kept warm it forms as readily after it leaves the udder as in it, and ordinary milk will as much—nay, more than new milk—produce it if it is kept covered and warm; but if milk is altogether boiled it cannot form. It is considered to be the result of germs which are produced at any time, but in greater and multiplying numbers when the cow is not in her ordinary state of health. It behaves as a ferment, multiplying with great rapidity under favourable circumstances. Keeping the milk in too large masses without stirring it, or having any disagreeable odour within reach, will produce the ever multiplying spores; consequently, cleanliness and care in regard to this susceptible ferment are indispensable.

Exposure to the Air.—Organic Germs.

Apart from animal odour, milk is of itself an unstable compound. It is continually undergoing change from its secretion till it is either manufactured or consumed. In the udder, busy absorbents which line the milk tubes carry into the general circulation part of the nutrient properties it contains; thus it loses a portion of fat, albuminoids, sugar, and water, and possibly, too, of its salts. But if drawn into a bottle or other vessel without exposure to the air, and so kept, it will not spoil for an almost indefinite length of time. Otherwise it attracts from the air the seeds of a fungus plant which grow, multiply, and produce souring—the arthrococcus cells of the savan. The boiling-point temperature will certainly kill them, but it is not considered that either cold or wet will, although the former will, when intense, at least hinder reproduction. One or two left on a milk vessel, or in one of its crevices, will, on being moistened with warm milk, again spring into active life, quickly produce millions, and premature souring results. There are also destructive agents which get into milk through the cow's body. These are the micrococcus cells of the learned, very minute and everywhere abundant. Within the snow lines of high mountains, as proved by the experiments of Tyndall on the Alps, they cannot, in otherwise favourable circumstances, spring into life; and, according to other experiments, when once formed no amount of cold will kill them. The heating to the boiling-point certainly disposes of them ; it is for this that green fruit is scalded, and with the desired effect. Milk is extremely susceptible of any ferment, it readily adopts its seeds, and even the flavour of a tobacco pipe will be imparted to it in a close compartment. Diseases have through its means been transmitted, and the peculiar smell of a cellar is readily detected in the milk which has been set in it. A good butter-maker will object to cooling warm milk in the same room where other milk is set for the cream to rise—the odour leaving the former being readily adopted by the other.

Souring.

When souring once begins it continues until the sugar is converted into acid. The whey begins to separate from the thickened milk, the vinous fermentation sets in, alcohol is slowly formed and takes up the volatile oils, the strong acid ferment acts upon the solid fats, and both quantity and quality of product are injuriously affected. Still longer will convert the alcohol into vinegar with even worse results. But there is a time in the souring process when the butter separates more perfectly from the other constituents. Acidity is well known to exert a powerful and beneficial action in the manufacture of cheese, and, although different in butter-making, it can also be turned to account. The acid as it develops thins and wears away the membrane which covers the butter globule, and at the stage when this is done, without the further action which has been shown to be deleterious, is the time to separate the butter. Further souring, besides making less quantity of butter, would, by breaking the grain of the butter, make it also more greasy.

Cream.

Butter is the whole available fat of the portion of the milk known as cream. Pure cream consists only of the fatty globules whose composition has been explained, and on the breaking or removing of the pellicle which envelops them, the fat is collected and butter formed. Even some naked fats moving about in minute particles in the milk, and originally derived from the essential oils of the food, may enter into the composition of butter. In extreme cases water may be present in the globules to the perfect exclusion of fat. Cream has a specific gravity of 983 to 1000 for water, corresponding with that given for the fats in combination, of which it is composed. Berzelius gives it at 1024, but when it is observed that this cream gave only 4½ per cent. of butter, and the residue 3½ per cent. of casein and 92 per cent. of water, it is quite evident that there had been a large proportion of milk in the cream. In value and in specific gravity cream nevertheless differs much. A milk giving 25 per cent. of cream, and analysed by Professor Arnold, gave the very disappointing result of 4 per cent. of fat, and 13 per cent. of dry solids. By and by the cream of the same cow's milk dwindled down to 12 per cent., the analysis showing only a slight falling off in solids, while the fat actually increased. Thus it is seen that quantity of cream is not an absolute test of butter product,. —opacity must be considered as well as bulk.

Milk Vessels and the Raising of Cream.

Various kinds, and of every conceivable form, are the vessels used for setting milk to the production of cream. The one in general use in this country is the common tin plate of 4 or 5 inches deep,— now much improved by being galvanised, or tinned, and without seam. These cool the milk readily without the use of cold water or ice, are light and handy, adapt themselves to almost any unoccupied space, and when empty store past inside each other into very small dimensions. They are, however, better suited to small dairies, in which butter in this country is principally made, the larger ones being mostly cheese-producing. In large dairies, and in the factories of America, either large rectangular vessels of a flat shape, and suitable for shallow setting, or deep and narrow cans for deep setting, are used. In the rectangular ones there is almost invariably, in America, a channel between two pans inside each other, or between a false and true bottom, into which cold water or broken ice can be introduced. The deep cans are only suitable for such countries as Sweden or America, where a very low temperature can be reached by the application of ice, of which more anon.

The antiquity of the separation of cream from milk might indicate in this age something like proficiency in the art. Nevertheless the best method is far from being settled, and the various ones practised have each its advocate, firmly asserting the superiority of that particular mode. Opposite practices thus increase confusion to the beginner, and this state of matters will not be much altered until manipulators have a much better idea of milk constituents, and the laws and circumstances which affect them. A short explanation of some of the leading principles may tend to establish a clearer road through the labyrinth of theories, ideas, and written and unwritten practice. Cream rises on account of its specific gravity, being less than the surrounding milk, the difference, however, being so slight that a very sluggish upward movement is given to the globules,—so much so that some of the smaller and more dense never rise at all. Sometimes even, from a difference of composition and consequent opacity, large ones may not rise; but the best portion always rises first and is highest coloured. Colour, flavour, and quality lose, but keeping qualities improve, with each successive skimming. But undue skimming,—say after 48 hours at 60°,—will deteriorate the quality, so as to do more than compensate for the small increase of quantity thus gained.

Fats expand and contract more than water with alterations of temperature, and the greatest difference of the specific gravity of milk and cream exists when hot, the least when cold. And as fat—the principal constituent of cream—swells more with heat, and shrinks more with cold, than water,—the principal one of milk,—it is evident that in an unvarying temperature cream will rise more readily under the influence of a high one. The colder the milk the slower the rise; because there is less difference in the specific gravity of the milk and cream, and also because the milk, then more dense, will obstruct it. This is illustrated in the making of whey butter, when a temperature of 170° is resorted to; because the difference of the specific gravity, caused by the greater swelling of the cream than the water of the whey, raises the former in a very short time. At half the temperature—85°—the difference being less, four times as long is required to bring up all the cream that will rise.

It has been observed by Professor Arnold that fat expands twice as much as water with the same increase of temperature,— from 60° to 130°. But in the ten degrees between 40° and 50° water only expanded one-tenth of the ten between 80° and 90°; and correspondingly, the same law affects shrinkage. In falling from high to low, water shrinks little, fat much, and the specific gravity thus becomes more nearly alike; hence the fat rises slowly at a low and unvarying temperature. From the fact of water being a better conductor, it feels the effect of heat or cold more readily than the fat in cream; thus, when the temperature is rising, the difference of specific gravity is diminished,—when falling, increased. At the same temperature' the difference is so little as to give only a very slow motion to the cream; but any serious alteration of temperature, from the effect of either heat or cold, will give, in the case of the latter, a hurried ascent, in the former, a scarcely perceptible one. And as some particular fancy as to a particular heat or depth has become firmly fixed in the mind of the dairyman, this accelerated ascent of cream in a falling-temperature has rarely in practice been turned to the best account.

As to depth, it is evident that cream will rise quickest through a small depth of milk; but still no particular depth can, without a due regard to volume and temperature, be set down as the correct one. For instance, two vessels of milk of even depth at 80° being set in a room at 50°, but with one of them previously cooled to the same temperature as the room, that one will not throw up the cream so rapidly or so perfectly, because it received no benefit from the difference of specific gravity arising from the falling temperature. But if it had been allowed to stand until the cream ceased to rise, and then rewarmed and set at 50°, or alternatively,—without being again warmed to the original temperature,—it had been set in a room 20° colder, so as to allow a farther fall of temperature, as good result would have been got as from the other vessel. Shallow setting will throw up best in a warm room; because in a cold one it goes through its fall of temperature so quickly that the cream has not time to rise, and, as before shown, a high temperature, when unvarying, tends to a quick rise. Milk spoils sooner when kept warm; yet milk two inches deep at 65° will throw the cream quickly and almost perfectly; but it would not do so at 50°, because the milk, falling quickly to the room temperature, loses the benefit of the difference of specific gravity before the cream is all up. At 65° it will rise through 2 inches perfectly before souring begins; but at 60° souring would begin before the cream was all up, and both quantity and quality would suffer. But if the deeper vessel were set at 50° the result would be different, the greater depth prolonging the cooling, so that the cream would be all up before the temperature of the room was reached. Thus it is easily seen that both deep and shallow setters may be right, if only the temperature through the range of which the milk has to fall in cooling be properly arranged. Larger or smaller volume together affects the temperature in cooling, and consequently cannot be overlooked in the arrangement. In cooling to a very low temperature, the slower the better, and deep setting and large volume tend in this direction. Thus bulk and depth require to be graduated in accordance with the point to which it is considered the milk can be cooled; and it is evident that shallow setting and small volume will suit warm countries, deep setting and large volume those of a colder normal temperature, and with facilities for the procuring and keeping a supply of ice. With shallow setting in a high temperature the depth should be made so that souring does not begin before the cream is all up. Cold water, in cooling milk, brings the cream faster at first than cold air; but the latter, from its being a worse conductor, and consequently at a disadvantage in the first stages, cools it more slowly, and which, if not overdone, will give most cream.

The greater the number of degrees through which, under proper arrangement, milk falls in cooling, the more perfectly will the cream rise. With an unvarying temperature it is better high than low, and thus a mistake has arisen into which many have fallen,—the ascribing the perfect rising to a low temperature by itself, instead of a constantly falling one. High temperatures induce the growth of organic germs, and the formation of sour milk cells, which retard some and altogether hinder other globules from rising. Cooling stops the multiplication of these germs, and boiling altogether kills them. These hurt the flavour of the milk and butter, and thus cleanliness and a better knowledge of the conditions of milk, cream, and butter under different treatments and temperatures become the best means of their prevention.

Skimming and Preparing Cream for Churning.

If butter making alone is contemplated, skimming may be begun when the consistency of the cream is such that the track of the finger, on being drawn through it, is not immediately filled up; if skim milk cheese is to be made, then it should be done much earlier—before souring begins. In deep vessels at a low temperature the cream will, however, remain soft long after it is all up. Milk which is cooled below 50° for the cream to rise will keep a long time, and a little will rise as long as it is sweet; but 60 hours is considered the maximum time, anything longer doing more harm than good. When the cream is all up skimming proceeds, and it is better to skim away a portion of the milk along with the cream, both making 25 per cent. of the entire bulk. For this course there are two reasons. Too much butter to the bulk of cream causes too severe handling of the globules in the churn, and there is a little butter got from the milk nearest the cream. Some churn, quite unnecessarily, the whole of the new milk; of course this is necessary when the whole bulk is lappered or soured. In deep setting the cream should be dipped off.

If cream were left long enough on the milk it would be entirely consumed by the germs and the fermentation induced by them, just as both animal and vegetable matter have been seen to fall a prey to this destructive agency. But in the incipient stages of this change there is a proper ripeness, or state of the cream, from which the best general result is obtained. A high temperature brings it more rapidly, and it is indicated by a moderate degree of acidity and pretty firm consistency in the coagulum. The acidity should alike pervade the whole bulk,—if some is sweet and some sour the latter will churn first and loss result; hence it is a good practice to mix the different messes,—stir them well and allow them to stand for 12 hours at 60°. If colder, it should stand longer; warmer, shorter. Even if only from one vessel it should stand until the whole is evenly ripened, for the top is relatively riper than the bottom. Cream spoils quicker than milk, and on this account should be kept cooler. But better mix with milk and churn than keep it long; and if for this purpose the temperature require to be changed, it should be done slowly, by placing the vessel in either cold or hot water as desired.

Lappering.

This is the term applied to a method of treating milk previous to its being manufactured into butter. It seems to be more common in Scotland and in Holland than any other country in Europe. It consists in setting milk in the ordinary way as for cream raising. Here the falling temperature is of no account. After it has been allowed to sit for 12 hours,—longer or shorter according to temperature,—it is then emptied into the lappering dish, generally, when made for the purpose, about 2 feet high by 1½ broad, and where, in summer, it soon begins to acidify. In winter it will not readily sour of itself, and consequently a little acid buttermilk is added to hasten the operation. It has been before mentioned the danger of allowing milk to become sour when cream is raised by the ordinary plan of setting. But the extent of acidity which produces the lapper is only on the road to the stage at which a greater degree will, by the production of alcohol, reduce the quantity and deteriorate the quality. Acidity, though a powerful agent for evil, is also, when skilfully used, a useful one to the cheese-maker, and little less so to the butter-maker. By a proper control of this agent unquestionably more butter will be produced than by any other method; some even say the quality is also improved, but to this the writer demurs. The acid thins away the covering of the butter globules, large and small alike, while those which rise in cream are never altogether the whole of those present in the milk. It is easily seen, then, how the greater quantity is obtained, and as acidity is not incompatible with a fine flavour in cheese-making, it may in butter be in a similar position. About 36 hours in the lapper dish, at a temperature of 65°,—in which time it will be sufficiently coagulated in summer without, and in winter with, added acid, —the churning may then proceed. The temperature may run from 55° to 60° in summer, as high as 75° in exceptionally cold weather, and with cows long calved in winter; but each place, and the accompanying circumstances, dictate a proper degree with which a manipulator should soon become thoroughly conversant. Electricity, by causing premature souring, reduces both quantity and quality as in cheese-making,—a result less noticed in cream raising.

White Specks in Cream and Butter.

These may be produced in dry weather by dry clots of cream, but generally they are broken up and mixed with the buttermilk in the process of churning. A much more usual cause is the coagulation of small portions of milk by the action of organic germs within. This is much more likely when, as before indicated, these germs begin their work,—at a time when the milk, from the cow being dried for the season, remains long in the udder,—in the body of the cow. "With the aid of the lactic yeast ferment, the germs obtained from the air and other sources curdle a little of the milk, the fermentation around forms a gas inside the fleck, and, being lighter than the milk, it ascends with the cream. Sometimes developed in the cream, it will coagulate a bit of milk and remain there, and when churned, the curd being tough, does not yield to pressure so as to burst. Scalding alone will cause them to disappear. They have been known to develop in one pan exposed to the light, while others away from it remained intact; and they have been known in the milk of one cow, while that of another similarly treated escaped. Butter will not suffer much from dried cream, but the origin of the others leaves no room for doubt as to their effect. Mixing and stirring the cream will prevent dried clots,—the germs once set in motion can not be destroyed without scalding. Butter with flecks, the produce of fermentation, will not be the best quality, and will neither keep long nor well.

Colouring. When butter is very pale, its appearance and market value are improved by a little colouring. The desired quantity of annatto—the best known material for the purpose—should be mixed with the cream before stirring and mixing, and in no case should colouring matter be added to the butter itself, as it cannot be perfectly incorporated with the butter, and will appear irregularly throughout. Colouring with carrots or other similar substance is objectionable, for the vegetable matter, soon decaying, lends decomposition to the butter with which it is mixed. Artificial colouring should only be sparingly used, as the natural hue is always the most perfect, and a very slight shade beyond will give an unnatural appearance.

Churning and Churns.

When butter can be worked so that the globules of fat of which it is composed remain unbroken on escaping from the enveloping membrane, it will, in a temperature of 60°, break like cast iron and show a granular structure. This is best seen under the microscope, and in trade is known as the grain of butter. Butter thus treated will keep better, and have a better taste and flavour, than if the granules had been broken,—in which case the butter becomes greasy, and will part like salve or green putty. In the latter state it will not keep well under any circumstances; in the former it will keep long and well under almost any disadvantages. And the keeping of the grain of butter whole is important, not only during, but after churning. Too cold churning will cause the grain to get broken by increased friction; too warm by the mixing of the softened fats. The object of proper churning is to break the pellicle without disturbing the granule within, and this is best done by combining pressure, rather than friction, with the required motion. Pressure acts on all the globules alike,—friction on those coming into direct contact. The old-fashioned upright dash churn fulfils well the desideratum. It should be slightly barrel-shaped, and the dasher either altogether round or with only two cross sections, which, taken together, come pretty near completing the circle. A rectangular box with a reciprocating motion, and dashing the cream against both ends alternately, a similarly shaped one rotating either from the centre of the sides or from the corners, and a barrel one revolving endwise, are good forms. The kind most in use is a fixed rectangular one, with a rotating dasher within,—on the principle of friction rather than pressure. The dashers within should have few notches, for these increase friction and tend to greasy butter.

The best temperature for churning, subject to modification, may be set down at 60°. Sour cream churns at a lower temperature than sweet, but if too sour more labour is required. Whole milk requires 4° or 5° higher than cream of the same acidity. The smaller the size of the dasher in relation to the space in which it works the higher temperature will be required. To churn in the same time, sweet cream requires 4° or 5° of higher temperature than sour, except in the case of Jersey cows. Distance from calving requires a higher temperature, and even then, on account of the smaller globules, may protract churning. Scalding milk when sweet facilitates churning, and when faulty or bad to churn this may be resorted to. When the cream gets frothy, and is either too long in churning, or refuses to give butter at all, it proves either that the temperature is too low or that it is too long kept. Alum also has this effect, and meal, soap, and a great many other ingredients, will prevent butter coming. In autumn or winter the temperature requires to be higher than in summer; but many forget that, along with this, another rise is required for the milk of cows which have been long calved.

Churning should proceed slowly at first, until the cream is well mixed, then at the rate for the churn; but no violent action should be allowed at any time, and when butter appears the rate should slacken. Butter gathered in the churn has more or less buttermilk in it, to be removed either by kneading or washing with water. The flavour is different, but, by the latter method, that of pure butter, and either way can be adopted to suit the taste of the buyers. If the water is pure the keeping qualities are improved; if it contain lime or any impurity it is better without. When the weather is warm, lime is better than pure water for improving the consistency. For this purpose the buttermilk is by some removed and replaced by cold water, as described in treating of Ireland.

The Working and Salting of Butter.

The working of butter is better accomplished by pressure than by rubbing or sliding it along any surface. Machines for the purpose are to be recommended, rather than the hot hands of a manipulator. The temperature should be about 58°, and no more strokes than needed should be given. Salting takes place after the buttermilk is expelled, and should be thoroughly worked into the butter. Set aside for a few hours for the salt to dissolve, it is afterwards reworked, so as to make it keep long and well. Salt is good when it keeps dry only, and from \ to 1 oz. to the pound is used, according to taste; but the smaller quantity is quite sufficient to prevent the butter from spoiling. An addition of from 5 to 8 per cent. of saltpetre, used along with a proportionally smaller quantity of salt, will, as an antiseptic, have a better effect. Sugar is sometimes used in this way, but the sweetish taste is to most persons objectionable. The making of fresh butter is so obviously like the description given to salt that little need be said in regard to it. The common way is to make fresh butter up in rolls of pounds or half pounds each; but it is also often made up in prints and fancy pieces of every conceivable shape, and giving evidence in some instances of considerable artistic skill. Shells, frosted leaves, and many other designs, are faithfully portrayed; and a description may be given of how it can very simply be formed into minute cylinders. The instrument used is of tin; a hollow cylinder open at one end to receive the butter, at the other there are only small perforations through which the butter must escape on being pressed with a wooden plug or roller fitting closely to the inside. Thus escaping as tiny cylinders, it resembles macaroni, and has rather a tasteful appearance on the table.

The Packing of Butter.

To preserve butter, or to put it in a convenient form for transport, it is necessary that it do not come in contact with the air, that it is not readily affected by alterations of temperature, that there is no damage or loss on account of leakage, and that from the vessel itself it receive no impure taste or flavour. In all metallic vessels there is the difficulty of their being ready conductors of heat, and a still greater difficulty in their liability to corrosion by the salt and lactic acid. Wooden vessels, if properly made and seasoned, have not, for cheapness and efficiency, been superseded, and are much more extensively used than any other. Made of oak, ash, or similar wood, and having the original sap removed by boiling water or super-heated steam, there is little damage of any abnormal taste or flavour being—through the vessel in which it is packed—imparted to the butter. But to prevent any danger, the vessel should be soaked in strong brine —made from pure salt—for at least forty-eight hours; when this is emptied out, it should be again filled with boiling hot brine, and when it is thoroughly cooled the vessel is then fit for use. The heads require the same treatment, as they, too, come into contact with the butter. The grain of the wood is, by this treatment, so filled with salt as to prevent air getting in. No flavour or taste can exude from the cask, and the butter next the wood will be as good as that furthest away from it, which would not be the case if soaked only in water or cold brine.

In packing, the first process is to spread half an inch deep of salt on the bottom, after which the butter is filled in perfectly solid, and with each succeeding layer the finger is run round the edge to smooth it into the cask, so that the air cannot enter between. When there is only room for a similar layer of salt between the butter and the lid, a piece of muslin of the same shape, but half an inch more than the lid in diameter, is put on the top. The edge of the muslin is, by a thin edged tool corresponding to the edge of the cask, trimmed down between the butter and the cask. The layer of salt is now spread, and over it the lid is firmly fixed. If the butter is intended for long keeping, the cask is turned with the bottom side up, in which an auger hole is made. Into this is poured hot brine, until it reaches the top of the stave, and thus with the entry of the brine air is excluded, and the hole is then plugged. Butter, if good to begin with, will, when thus treated, go round the world, and be sound at two years' end. Tubs, usually too heavy, and being more difficult to fasten, have not grown in favour. The old-fashioned earthenware crock is very suitable for the preservation of butter, but the cover is difficult to fix, and from its fragile nature is best suited for short transit, and under the care of interested parties.

Irish Notes. Irish practice is similar to British, and the prize essays of the Cork Agricultural Society, newly published, present no very distinctive features. The milkhouse recommended, and so far adopted, is one with mud walls and thatched roof—these being in a high degree non-conductors. The roof is also to overhang and be supported with posts, so that in the space thus created the vessels can, without getting wet from rain, have access to atmospheric influence. No direct access to the kitchen and scullery is to be tolerated, and one of the essayists would prohibit the entry of any one with shoes which had been used outside. The whole three of the Cork Society's reporters have, however, failed to get hold of the scientific reasons for the regulation of volume, depth, and temperature, and each of them is treated independently of the others. No mention is made of lappering or acidifying, a practice which certainly must be known in Ireland. Broad and shallow setting is recommended with a temperature of 55° to 60°; the first prizeman more than once asserting that at the former "cream is best generated," and that cream "will not readily rise" below it. He advises the use of the refrigerator for milk to be set for cream to rise—a practice defying the benefits to be derived from the more steady falling of temperature and the consequent difference of specific gravity between the milk and cream, and which allows the latter to rise more quickly and perfectly. In speaking of " another mode of producing excellent butter," he considers the raising of temperature to 140° as being for the purpose of dispelling odours, but the practice is connected with the better scientific knowledge of America and Sweden than Ireland, and is, no doubt, for the purpose of giving a wider range of temperature in falling, and even farther extended by ice application. The application of nitre, boiling water, and sour cream, are considered to dispel the flavour induced by cabbages and turnips. The abstraction of the butter milk, and the repeated substitution of cold water at the finish of the churning process, is recognised in all countries in which hot weather renders the butter "soft." But all through, and especially in the experiments noted in cream raising, it is obvious to a very elementary scholar in the technical education requisite for butter making, that the chemical bearings are a hidden mystery.

The packages for export are considered too large—at 60 to 70 lbs.—for the smaller Irish makers; for they have either to wait too long to fill one, or enter into partnership with a neighbour. In the "midlands," however, they are much smaller, and of a tub shape, and the whole of them are manufactured from white oak. The cylindrical shape, admitting of being rolled about, is now giving place to one wider at the top than the bottom. Over salting, reaching as high as 6 or 7 lbs. to 70 lbs. of butter, is condemned as "penny wise and pound foolish."

Foreign Notes.

In Europe a line drawn from the Pyrenees through the Cayennes and the Alps, and along the lower Danube to the Black Sea, or east to west obliquely from 43° to 46° N. lat, would almost separate the butter from the oil countries. In Italy, Spain, Portugal, the south of France, and the south of Turkey, butter is an article of limited consumption, being mostly sold in very small quantities from the shops of the apothecary, and superseded by the oil of the olive groves of those countries. On the American continent butter making is extensively carried on in 36° N. lat.; but it must be borne in mind that the influence of the Arctic and Pacific currents makes the temperature much lower than at corresponding European latitudes.

The butter manufacture of Great Britain does not exceed 550,000 cwts. It obtains 400,000 from Ireland, and from abroad are imported 1,600,000, the largest proportion of which is from France; next in order following Holland, Denmark, Germany, Belgium, Canada, and the United States. Prom February till April, Kiel is considered best; from April till October, Normandy and Friesland; and from October till February, German and American brands are in favour.

France.—The best salted butter is exported from Normandy, made from the Jersey cow, and finds its best market in Brazil. It is first packed in small firkins, of which a number are closely packed into a cask, the interstices filled with brine, after winch the cask is firmly kneaded so as to exclude air, and the butter is then warranted to keep for three years. Its largest export of butter is, however, to England—in 1876 reaching a value of close on £4,000,000 sterling. A lesser quantity is sent to Belgium, South America, and the West Indies. That which finds its market in Britain is mostly fresh, and is made as follows: The butter is churned from very sour cream, washed in the churn, and not salted at all. The keeping qualities—evidently not of a high order—are not very material, for it is all consumed in a few days from the time of its manufacture. It is put up in 1 lb. rolls, covered with jaconet and lace paper, and packed in boxes 14 x 9 X 6 inches each, holding twelve rolls, and furnished with appliances for refrigeration. One M. Lepellatier exports 1200 boxes a-week. The best butter for home consumption is put up in large balls—28 to 40 lbs. each—covered with flannel, and packed in wicker baskets; the second and third class being put up in 1 lb. rolls and packed in grape leaves. In experiments with the raising of cream, as related in the "Journal D'Agriculture Pratique," it is demonstrated that milk newly drawn, and submitted to temperatures varying from 0° to 36° Centigrade [To convert into Fahrenheit, multiply by 9/5, and add 32.] and kept at the same initial temperatures for twenty-four to thirty-six hours, gave the following results. One vessel at 22° C. gradually increased in cream from 4 cubic centimetres—in a volume of 200 of milk—in one hour after the milk had cooled to the same temperature as the water in which it was immersed, to 11 c.c. in fifty-two hours from the same time. One at 15° C. almost similarly rose from 7 to 12, while, very strange to say— one at 2° C. as gradually fell from 29 to 17 during the space from the one till fifty-two hours. The conclusions arrived at were, 1st. That the nearer the setting temperature to 0° O, the faster will the cream rise; 2nd. The cooler the temperature to which the milk is submitted, the greater will be the volume of cream; 3d. The proportion of butter also is greater with the cold setting; 4th. That the skim milk, butter, and cheese, are beneficially affected by a low setting temperature. Twelve hours was considered sufficient time for the cream to rise when cooled to 2°, twenty-four hours at 6°, and thirty-six hours when only cooled to 14° or 15° C. Butter made from milk cooled to 2° was fresh and sweet at fifty-two hours; while that to 15° did not give butter of so good colour or flavour, and it became rancid in thirty-six hours. It cannot here be fully explained why these experiments may in the highest degree be misleading—the foundation of the erroneous teaching displayed being the treating of temperature without any due regard to the correlative ones of depth and volume.

Denmark.—From this country there is exported annually— principally to England—but also across the Equator, to China and Japan, an amount of butter, partly purchased from other countries representing a value of nearly £2,000,000 sterling. The general practice in regard to setting is that invented in Sweden by Swartz of Hofgarden, and what is known as cold and deep setting. But in 1878 M. Fjord, of Copenhagen, having received a grant of £800 from the Danish Government for the purpose of carrying on research in the treatment of milk and the manufacture of butter, has demonstrated that, by a centrifugal cream separator, more cream will be given than by any of the common methods. But in the experiments it ekes out that, when set in wooden vessels, the cream was only 4½ per cent. short; proving that the cooling was too quickly gone through, and that it was only by chance that in one of the methods volume and depth had been graduated to suit the lowest point of cooling. In a subsequent experiment, the centrifugal method, the ice cooling and that of setting in wooden vessels came more nearly alike. It is not, however, claimed that in summer the machine will excel the ice method—it is only superior in the case of milk which is sluggish in throwing up the cream; thus proving that, after all, the supposed increase is due to want of management in the other methods. However, if the machine is more certain, and without the care and calculation necessary for the other methods, it will still be an improvement. It separates the cream from the milk in thirty to forty minutes, and one for 20 gallons requires three horse-power to drive it. The price is £150, and on that account alone will not soon be in general use.

The following is an account of the packing of Danish butter as practised by a company exporting 2½ millions of pounds annually. The tinned-iron boxes are made on the premises of material procured in England. The sheets are cut into strips and bent by machinery. The edges are then soldered together, and the bottoms and lids are also made by machinery and turned up at the edges. The bottoms being next soldered on, the boxes are first steeped in hot water, then in a soda lye, and, lastly, are thoroughly rinsed in cold water. The cellar where the packing proceeds is one-half underground, 3 metres in height, and ventilated by a rotating apparatus which effectually removes the smell of the butter. The temperature is maintained at 59° Fahr., and the casks contain 150 lbs. each. Only pale-coloured butter, slightly salted and made from sweet cream, is admitted. The company buys up butter in Sweden, Norway, and Germany; and their factor gets £1000 a-year. The butter is received from those countries in wooden casks; and the outsides of the butter are— for fear of a taint from the wood—pared and sold to retailers at a reduced figure; then, cut into flat pieces with an iron wire, it is kneaded together by machines of American construction, during which process a little salt is added, after which it is packed in the vessels described. A little round the edges is removed to give convexity, and the covers are then soldered on in a current of air calculated to remove the smoke and acids generated in the process. The closed vessels are then rubbed with sawdust and paper dipped in a solution of aniline violet, and set on a perforated table to drain. The labels are then affixed. The tins are packed in larger wooden boxes bound with iron and having the vacuities filled with rice husks, and, being finally headed, are considered ready for export.

Norway and Sweden.—M. Dahl of the Agricultural School of Arts in Norway is responsible for the following:—160 quarts of milk, on being submitted to a temperature of 3° C. for thirty-six hours, produced 240 lbs. of butter; while from the same quantity in the same time at 18°only 210 lbs. were obtained. The comparative return would have been still more in favour of the low temperature at twenty-four hours. But a very full and clear description of butter-making in that part of the world has been furnished to the writer by Axel Bergwell, Esq., a gentleman who, along with another Swede, visited this country in 1875, and inspected a few of the larger dairies in Galloway.

In describing the system invented by Swartz, he proceeds as follows:—The cisterns, made of wood, are 2½ to 3 feet high, 3 feet broad, and with the length depending on the quantity of milk. As the milk varies in quantity throughout the year, it is better to have three smaller than one larger one, on account of economy in the use of ice for cooling—the principal element of the system. The depth of the water is kept at its proper place by having a hole bored in the cistern at which it may escape. Five inches from the true bottom there is a false or lattice one on which the milk vessels are set. The temperature preferred is below 4° C, only attained by the use of ice; when cold water is used, lower than 6° or 7° is rarely obtained. The vessels in which the milk is cooled are of iron covered with tin, oval shaped, 2 feet deep, 1½ foot at the broadest and 7 inches at the narrowest width. These milk vessels are filled to within 3 inches of the top, and hold 9 imperial gallons. They are set on the lattice bottom with the surrounding water in a horizontal plane with the top of the milk, and with 6 or 7 inches between them, so as to allow the ice to be packed between the vessels as well as between them and the sides of the cisterns. Thus the milk is reduced to 4° C, and, if properly managed, will fully separate the cream in twenty to twenty-four hours; and less will be gained in increased quantity of cream than will be lost in quality of it and the skim milk, and in ice consumption by any further delay.

Running water will not separate the cream so quickly; but, if not more than 6° or 7°, it will separate in thirty-six hours. It is thus a matter for calculation whether the cost of procuring and keeping ice will not more than counterbalance the small loss of cream. By the method described, the milk keeps sweet for a week; and less number of vessels, less room, and, consequently, less cleansing are required.

He then describes the making of butter thus:—There are two ways of making butter in Sweden—either by churning sweet cream, or by letting it get somewhat sour. The latter gives more butter by exact experiment, but it has a stronger aroma; still, churning from sweet cream is becoming more common, partly because it is a trouble to notice the exact acidity required, and partly because the skim milk is so much better for cheese making. Churns, as a rule, are wooden; the Holsatian churn, in which two vertical wings are driven by horse-power, being the the most common in the larger dairies, the other being the common box with a round bottom, and the dasher driven by an ordinary handle. The cream at the beginning should be 13° in summer, 14° to 16° in autumn, and 16° to 18° in winter. The temperature is, however, regulated by the place as well as the season, and the condition of the milk has also an influence. Strict observation will, however, find out the proper temperature for every place and under every condition. If atmospheric changes render an alteration of temperature desirable, it should be by cautious movement, not more than ½° at a time. Churning should be slow at the commencement, and increase gradually to the required speed, after which even turning without interruption will secure the best results. In about half an hour the cream should commence to break—found by a grainy feel on the finger. Especially in summer, the temperature rises in churning, and cold water or ice should be used to bring it to the starting-point ; this will make the butter more solid, and assist the separation of the butter milk. If ice is used, it should be broken small. Often in winter it is requisite to raise the temperature, and this should be effected by adding, in small quantities, water of from 35° to 40°. When the butter is formed and pretty well separated, the speed should be slackened, and a few slow turnings will make the butter ready for removal. Altogether, the time occupied should not exceed forty-five minutes, or else, if got as otherwise directed, the butter will not be good and solid. In warm weather, if the butter milk is not to be sold, one-third to one-half cold water can be added to the cream; but warm water in winter must be sparingly used. Sometimes butter comes too quickly, then it is soft and greasy; sometimes too slowly, so that several hours are spent in getting what is generally bad butter; sometimes it cannot be got at all. The management mostly accounts for the difficulty; for bad fodder, frozen turnips, and especially potatoes, or a large quantity of sour distiller's waste, will all more or less injuriously affect milk and butter. Disease of the udder causes either bad butter or none at all.

The cream-separator mentioned in connection with Denmark has been eclipsed by a Swedish engineer named Laval. It requires only two men to drive it, and its action is continuous. When kept in motion and supplied with milk, cream is delivered at one spout and skim milk at another. It is cheap compared with the Danish one,—£25,—and is said to give better results in cream and butter than any known method, only three-tenths per cent. of fat being left in the butter milk. Thus, in 1000 lbs. of cream, only 3 lbs. will go into the butter milk—looking like the acme of perfection in this direction.

Switzerland and the Tyrol.-—In Switzerland, as soon as the milk is drawn it is filtered through a sprig of washed fir-tips, the stem of which is inserted in the narrow opening of the dish used for the purpose. Hairs, clots, or gelatine sliminess, are deposited on the wiry leaves—in fact, it answers all the purposes of a sieve, and is all the time imparting an agreeable flavour to the milk, and, to a less extent, also to the butter. A fresh sprig is used every milking. In the Tyrol, milk is set in small shallow pans and cooled with ice or compressed snow, and the cream rises in twelve hours. The temperature is here, as in the French experiments, too much relied on; for shallow setting will certainly cool the milk so quickly that in cold weather especially, a loss of butter will result.

Germany.—The greater part of German butter is known as Hamburg, and consigned to the English market. Schleswig-Holstein furnishes the largest quantity and best quality, next comes Mecklenburg, then East and West Prussia. The butter designed for export is coloured higher and more salted than that for home use; and thus some of the provinces, which have only a moderate status in the English market, stand high in Berlin. In South Germany the butter is never salted, and taste and consistency are of much more account than colour. Preserved butter is also made, and, hermetically sealed in tins, is mostly exported to tropical countries. The setting of milk and the raising and churning of cream into butter, are very little different from the practices of Sweden and Denmark in the north, and Holland and France in the south.

America,—The whole economy of butter making is in this country either a modification of, or more generally an improvement on, the methods practised in Britain and Sweden. The former may be reckoned the patron of shallow setting, the latter that of deep; and it is not difficult to see that both methods may be justly approved where, as in America, there is such a wide range of latitude and temperature; but deep setting, large volume, and cooling to a low temperature, have now most advocates in America in the rather low temperature of the dairy belt, and the competitive experiments of Hardin and Reeder endorse this practice. The former, by his plan of deep setting, got 1 lb. of butter from 17 lbs. of milk; the latter, by the shallow plan, took 19 lbs. for the same quantity—both being from the same quality of milk, that of Jersey cows. In a subsequent trial the deep system maintained its superiority, and gave 1 lb. of butter from 14½ lbs. of milk. It is, however, quite evident that, even although the deep system is preferable, it would be neutralised by the expense of procuring and keeping ice in warm countries, and in this America, Sweden, and other comparatively cold countries have an advantage. The buildings in America have many devices for regulating and controlling temperature, and this it is evident that we should imitate. Double walls, with the intervening space stuffed with the refuse bark of tanneries or sawdust, cisterns, and streams of cold spring water, all are called into play for giving the temperature desired. In the storing of ice there is also something to be learned; and it is quite possible that by and by, even here, every farmer will have an ice-house. In a sheltered place and facing the north an underground receptacle, properly drained, with double walls stuffed between with bark and a thick thatch roof, would, at little expense, give ice the year round, and be useful among others for the purposes of the dairy. The factories where butter alone is made are, in America, distinguished from those where skim milk cheese is also made by terming the latter creameries.

The Americans, too, have found out that more butter is had by allowing the whole of the milk to acidify than by raising the cream. By experiment, 28 lbs. of milk by the former method gave 1 lb. of butter, while by the latter it required 38 lbs. But they have also discovered that, when skim milk cheese is made, the apparent loss in butter is turned into a gain in the better quality of the cheese. Whey butter is also sometimes made,— 200 lbs. of whey giving 1 lb. of butter, but it is greasy and strong flavoured.

The methods of setting milk in America being different from those practised in any other country, it is important to notice some of those most highly approved. Hardin's method, previously noticed, consists in emptying the milk as drawn into deep cans, which are set in a wooden box constructed to hold a number, and excluding the air entirely. A shelf above is filled with ice, and the water from the melting ice runs through a perforated margin below the cans. The milk is 18 inches in depth, stands in the water to a depth of 4 inches, while the surrounding air is 49° Fahr. The cream is taken off in about thirty-six hours, and churned at a temperature of 58° in summer and 63° in winter,—forty strokes to the minute usually producing butter in twenty minutes.

Edward Burnett, Massachusetts, has a modification of this plan, applying ice to the upper portions of the cans only, and which are made wider at the top to give a greater cooling surface. The lower portion is then of the surrounding temperature, whatever that may be. His belief is that the cooled milk as it descends leaves the cream, which is less dense at the top; but, like all deep setters of any note, he is profuse in the use of ice, —taking 200 lbs. for every 90 gallons of milk. He also excludes the air.

The Cooley system is the newest, and getting a popular one. His pans are 20 inches by 8 inches broad, and, like the preceding, they are enclosed in a box as soon as the milk is drawn. Each can is covered with a small pan like a milk plate, with the convexity upwards, and held in its place firmly by wedges. The box is then filled with cold water, the pans keeping the water out of the milk on the principle of the diving bell. If the water is below 50° a stream of it is kept entering and passing-out by an overflow. If cold enough water is not available, ice is used to keep it down to between 40° and 50°, and it is found that all the cream is up in twelve hours, and the dishes are thus ready to receive the next meal. No account is taken of animal odour; but atmospheric ones are excluded by the complete immersion in water. By an ingenious device the skimmed milk is withdrawn from below, and the cream, left alone, is then poured out. This system saves dishes, and with the low temperature less scalding and work are necessary. It is maintained that, from Jersey milk, a depth of 17 inches by this process gave 6¼ inches of cream.

Mr James M'Adam, a name well known on both sides of the Atlantic, communicates the following:—Illinois makers heat the milk to 160°, then set it in an air-tight tin vat, encircled with a stream of iced water, which reduces the temperature to 40°. The cream rises perfectly in twelve hours, and the minimum of curd,—well known to affect butter injuriously,—is thus obtained, and the keeping quality improved. This, like the method spoken of by the Irish reporter, gives the desideratum of a long range of temperature through which the milk has to fall in cooling. But it would be interesting to find out whether or not the common complaint of American butter going off flavour is due to the exclusion of milk from the air before the animal odour has time to evolve.

The curing and packing is similar to that practised in Britain. Earthenware jars are used for home consumption, but they are much better fastened than those in use in this country. The wooden cover has turned hooks, which fasten to a projection on the jar, and which can be screwed together until the fit is a fast and air-tight one. This also helps to save breakage in moving, and when closely packed together. The butter remains long in a good condition, as the cover excludes air, and the stoneware is a bad conductor of heat.

It may, then, be concluded that with a normal temperature of 40° to 70° pretty uniform results may anywhere be obtained. The lowering of the temperature through a long range is no doubt an advantage, but this should only be done gradually, and deep setting is thus inseparable from the use of ice and very cold water. Raising to 160°, as in Illinois, might reap a long range without the use of ice; and it would be interesting to find out how much it differed, in falling from 160° to 50° or 60°, from that between 90° and 30°. No doubt the shrinkage would be greater at the higher temperatures than the low ones, according to the research of Arnold; but to what extent it would affect the butter product has not evidently been solved. Shallow setting and small volume will, although evidently inferior to the other, maintain their pre-eminence in warm and even temperate countries; for against the gain in butter has to be put the loss in skimmed milk for cheese making, or even butter milk for pigs, and the expense of procuring and keeping ice. With low temperatures the consistency and keeping quality are improved, and, if air is not excluded, the flavour would also be better. The superiority of the flavour of the best English and French, with shallow setting, and of Swedish and Danish, with deep setting and contact with the air, as contrasted with American, leaves little doubt as to the cause of its becoming coarse in flavour. But it does not, however, follow that in this country we would not improve by adopting, to a considerable extent, the use of cold springs and ice in reducing the temperature of milk in the summer season; and for this purpose a closer investigation of foreign methods, with a greater experimental range at home, might lead to more eminence in butter manufacture. The greatest wonder is, however, that in all butter countries the reasons for studying in correlation, the volume, depth, and temperature are but little known; and until a more general knowledge of them is attained success in butter making will be irregular and uncertain.

Percentages and Quantities.