August 8, 1890.] 



SCIENCE. 



75 



metal plate of a screw-press. A dozen of these cloth bags 

 ■cover the surface of a plate. When one plate is covered, 

 .another one is let down and filled. 



When the press is filled, pressure is gradually applied by 

 means of an endless chain revolving a screw. The expressed 

 oil constitutes the oleo oil. This liquid fat is conducted, still 

 hot, from the press into barrels or cars, where it is allowed 

 to cool. The finished product is nearly colorless, tasteless, 

 and at ordinary temperatures is a soft, granular fat, rather 

 than an oil. The hard fat remaining in the filter-bags is 

 removed from the press, and forms the beef or oleo stearine, 

 which is used either for making refined or compound lard 

 by the addition of cottonseed oil, or sold to the soap and 

 candle makers. 



The manufacture of neutral lard is conducted by essen- 

 tially the same machinery and at about the same temperature 

 employed in the manufacture of oleo oil. Only the leaf-fat of 

 freshly slaughtered hogs is used. A hog yields from 5 to 15 

 pounds of leaf-lard, averaging 9 pounds, 100 pounds of which 

 yield 90 pounds neutral. The neutral, however, is not 

 pressed to extract the stearine, but is run directly from the 

 rendering-tank into a very strong iced brine, where it re- 

 mains for about twenty-four hours, when it is removed, and 

 placed on shelves to drain. The neutral is a white, slightly 

 granular, tasteless, solid fat. The skimmings and scrap 

 from the lard-rendering kettles are strained, and the fat 

 {about 2 per cent of the original charge) obtained from them 

 added to the steam-rendered product. Several factories, how- 

 ever, use the ordinary steam and kettle-rendered lards, and 

 not neutral. Great cleanliness is observed throughout both 

 processes, and there is very little manual handling; ma- 

 chinery being used as much as possible, and the fat carefully 

 guarded from any source of contamination. 



The by-products of oleo oil and neutral — viz., stearine, 

 •tallow, and lard — are standard merchantable articles. Only 

 fresh and sweet fats are used ; and tanks, etc., are thoroughly 

 cleaned before use, as a small amount of fat, if allowed to 

 -adhere to the apparatus, is liable to decompose in such a way 

 as to spoil the succeeding batch of materials worked up. 



Though there may be slight differences in the details, the 

 range of temperature, size of tanks, etc., pursued by the dif- 

 ferent manufacturers, the general procedure is as above de- 

 scribed, the object being to obtain a neutral fat, melting at 

 butter temperatures. 



The vegetable oils are prepared by crushing the seeds, etc., 

 and subjecting the crushed mass to hydraulic pressure, or by 

 extracting the oil by carbon bisulphide or other solvent. The 

 tcrude oil thus obtained is refined to remove the coloring- 

 matter by treatment with mineral acids, and subsequent 

 neutralization by alkalies, and chilling and pressing, whereby 

 ■a. product is obtained of a light straw-color and bland taste. 



The butter used is always selected for its high flavor and 

 "taste, and is generally obtained direct from the creamery. 

 •Owing to the granular character of oleo oil it becomes nec- 

 •essary to add some softer and smoother fat ; and neutral lard 

 and cotton-seed, or other similar vegetable oil, are added for 

 ihe purpose of making the mixture more closely approach 

 fhe consistency of butter. The proportions in which these 

 ingredients are used vary with the seasons of the year, the 

 ;grade desired, and the formulas of the manufacturers. The 

 icharge of milk or cream, however, is the same for all grades 



manufactured by any particular factory, and varies from 10 

 to 20 per cent. The milk or cream is allowed to become 

 slightly sour. 



The churn used is steam-jacketed, of 1,200 to 2,500 pounds 

 capacity; and the whole operation of churning is conducted 

 at a temperature of 85'^ to 105'^ F., insuring the melting and 

 thorough mixture of the solid fats used, thus differing from 

 ordinary creamery practice. The oleo oil and neutral lard 

 are melted in separate kettles at a temperature of about 90° 

 F. The charge of milk or cream is Qrst run in, and the 

 paddles kept in motion until the butter begins to form. Then 

 the charge of melted oleo oil is added and stirred. When 

 this is well incorporated, the neutral lard is run in, and 

 finally the annotto, to give the desired butter-color. The 

 butter is added either directly into the churn, being first 

 melted, or it is worked into the oleomargarine after it is 

 taken from the churn. The temperature is carefully regu- 

 lated, being about 85° F. at the beginning, and gradually 

 increasing to 105° F. at the end, when the whole charge has 

 the appearance of a yellowish, creamy fluid. From twenty 

 to ninety minutes are occuijied in the churning. The whole 

 melted charge, after it has been sufficiently churned to 

 thoroughly incorporate all the ingredients, is run either di- 

 rectly into tanks containing chopped ice and constantly 

 stirred, or is met by a stream of ice- water as it issues from 

 the churn. The object is to give the melted mass a fine 

 grain by this sudden cooling. The chilled mass is removed 

 from the tanks, and placed on wooden trays to drain. Here 

 the salt is added and allowed to work itself in, which gen- 

 erally takes from twelve to twenty-four hours. The salted 

 mass is then thoroughly worked by mechanical rollers, to 

 remove the buttermilk and water, following the general 

 practice of ci'eameries in this and subsequent operations of 

 packing, etc. 



Oleomargarine is placed on the market either "solid 

 packed " or in prints or rolls. Four grades are generally 

 made, known as "dairy" and " extra dairy oleomargarine," 

 creamery," and "extra creapoery butterine," the last two 

 containing from 10 to 25 per cent of the best creamery butter. 

 In the lower grades, from 25 to 60 per cent of neutral lard, 

 from 20 to 50 per cent of oleo oil, from 5 to 35 per cent of 

 vegetable oils, and in some cases from 2 to 10 per cent of 

 butter, with 10 to 20 per cent of milk or cream, are the pro- 

 portions used. Some factories employ no vegetable oils in 

 their oleomargarine, preferring to use a larger proportion of 

 neutral lard with a small amount of butter to obtain the de- 

 sired butter consistency. In the higher grades the propor- 

 tions of oleo oil are reduced, the vegetable oils are discarded, 

 and creamery butter is used to make up the charge. 



[To be continued.] EdGAR EICHA.EDS. 



NOTES AND NEWS. 



It is reported that a deposit of coal of good quality has re- 

 cently been discovered in West AustraUa. 



— The enormous increase in the frozen meat export trade from 

 New Zealand during the past few years must be exceeding grati- 

 fying to all persons interested in the colony. The value of the 

 exports to Great Britain in 1882 amounted to only about nine 

 two thousand dollars, while in 1887 it had risen to upwards of two 

 million dollars. Over a million carcases of mutton are now sent 

 annually to England, and there seems to be every prospect that 

 the trade will go on increasing at a similarly rapid rate. 



