Malt The malt as it comes from the lower kiln is not yet suitable for brewing as it contains the rootlets and some kernels that were crushed or injured on the floors or during conveying. The malt now passes through cleaning machines consisting of sieves and blowers which remove the rootlets, dust and small and broken kernels.
Mechanical As floor malting is restricted to only the cooler months of the year and possesses other disadvantages as to cost of labor and buildings, mechanical systems are coming more and more into use. The steeping of the grain as well as the kiln drying, however, remain generally the same as in the floor sys tem.
Pneumatic Floor This system employs box-shaped compartments to hold the grain during the growing period. Through this receptacle air that has been purified and •given the proper degree of moisture, as well as cooled or warmed to the proper temperature, is circulated. The conditions of temperature and humidity can thus be made the same all the .year round no matter what the conditions of weather may be outside. The green malt in this system is not turned by hand, but by a series of screws or propellers driven by power, traveling through it at regular intervals.
Drum The advantages here are similar to those stated above. The drums con sist of two concentric cylinders having the same ends. In the space between the cylinders the steeped grain is placed, this space not be ing filled quite full. The cylinders are per forated with small holes so that moistened or heated or cooled air can be forced through the grain from the centres or sucked through from the outside. By revolving the drum the grain is constantly tumbling, that is, the kernels nearest the inside cylinder fall against the out side cylinder, and this in connection with the air current passing through gives the same turning and aeration to the grain as in turning a heap in floor malting, and requires no labor. There are several systems of malting drums, differing principally in the manner in which the air is warmed and moistened and the di rection in which it is forced through the drum.
Brewing Materials, Operations and Equip ment, Especially for the Production of Lager Beer is produced from the materials, mainly barley-malt, hops, water and yeast, through the processes of cleaning and crushing the malt, mashing of the malt (with or without other cereals) ; straining or filtering the resulting solution which contains the ex tractive substances of the materials from the grains or insoluble portion: washing out the grains with hot water; boiling this solution, which is now termed wort, together with hops; straining or filtering the hopped wort from the spent hops; cooling of the wort; adding yeast for fermentation; drawing off the fermented beer ; clarifying and giving life to the beer; racking the beer into trade packages.
Besides these operations, which more par ticularly concern the character of the finished product, there are many supplementary oper ations necessary as precautionary measures to ensure freedom of the beverage from taint or contamination of any kind, such as foreign odors or ferments, by varnishing of all large wooden receptacles, such as tanks and casks; staining or otherwise coating iron vessels, such as hop-jack; pitching the wooden trade pack ages, such as barrels and kegs; thorough cleansing of all beer receptacles and utensils, aseptic or antiseptic treatment of all wort or beer conduits and of cellar floors, walls and ceilings by applying suitable washes, paints or calcimine; treatment of brewing and boiler feed water, etc.
Brewing Materials.—The materials used in the United States are principally the follow ing: Barley malt is the most important and generally used. It gives to the beer not only its substances, but also to a great extent its character. Malt also supplies peptase and diastase, two substances that change the nature of certain other constituents during mashing. Peptase changes the insoluble albuminoids of the malt into soluble or desirable ones. Dias tase changes the unfermentable starch con-• tained in the malt and other materials into fer mentable sugars and dextrins.
Caramel and black malt, consisting of or dinary malt that has been treated differently during malting, are used to impart color to the wort in order to produce darker beers, also to impart to the beer a more pronounced malt aroma or flavor. Only a small amount, propor tionately, of these are used mixed with other materials.