BREWERY BY-PRODUCTS 103 



ing the hulled seeds. These two by-products when ground together con- 

 stitute millet bran. 



Buckzvheat bran is a by-product of the manufacture of buckwheat 

 flour and buckwheat meal. It is liable, under certain conditions, to cause 

 buckwheat disease, fagopyrism (see p. 53). 



Rice feed-meal is produced as a by-product when rice grains are pol- 

 ished. This should contain no hulls, but frequently these are added and 

 ground into a mixed meal. The rice hulls, or glumes, are fery silicious 

 and consequently hard to digest. Even when quite fresh, rice feed-meal 

 contains free fatty acids and consequently has a sour smell and an acid 

 reaction. When fed to cows the butter is soft in character. Swine fat- 

 tened on this meal produce soft meat and bacon. This efifect can be 

 counteracted by simultaneous feeding of pea or barley meal : 



So-called rice bran is composed chiefly of hulls and broken kernels. 



Corn bran and corn feed-meal are characterized by their high fat con- 

 tent. 



In the factory manipulations of the seeds of legumes the outer leathery 

 skins (almost wholly indigestible) and the seed germs with some of the 

 starchy matter, etc., constitute the by-products. 



These substances are frequently ground up together and put on the 

 market as corn bran. Compared with rye or wheat bran, this material 

 is of very inferior value. 



VI. Brewery and Distillery By-Products, Etc. 



This group includes the by-products of (1) breweries (brewers' 

 grains, malt sprouts, hops and yeast), (2) distilleries (distillery slop), 

 (3) wineries (skins or husks of pressed grapes), (4) cider presses 

 (pomace of apples and similar fruit). 



1. Brewery By-Products 



The principal steps in beer brewing arc : Soaking the barley in water, followed 

 by spreading it out in a layer and the sprouting of the grain, and the formation of 

 a ferment which converts starch into sugar (so-called diastase and peptone) . When the 

 sprouted germ has attained one or two times the length of the grain the germinating 

 process is artificially interrupted by drying (55° to 100° C). This is followed by- 

 partial caramelization and the formation of aromatic substances. 



The sprouts (malt sprouts) are then removed from the grain, which is known 

 in this stage as malt. Malt has the external appearance of barley but possesses a 

 pronounced sweet taste. 



The malt is then digested in water at a temperature of 60° C. (malted) until the 

 starch has been converted into malt sugar and dextrin and the latter have become 

 dissolved. The fluid, mash, is then separated from the grain (brewers' grains) 

 and boiled with hops, thus made into wort, filtered, cooled in special apparatus, and 

 then fermented in special vats with the aid of yeast. After fermentation is com- 

 pleted and the fluid has cleared by settling, the beer is ripe. 



Malt sprouts contain 12 per cent of water, 11.4 per cent digestible 

 protein and 39 per cent starch value. The lighter in color that malt 

 sprouts are, the more easily they are digested. In a general way they 

 are a valuable concentrate feeding stuff for horses (up to 6 pounds), 

 for fattening cattle and milk cows (2 to 4 pounds), for swine (1 to 2 

 pounds), for sheep (>4 to 1 pound). They should be soaked or scalded 



