BREWING and BREWERIES. Whether ale or beer be the object of the brewer's at tention, the chemistry of the manufacture is pretty nearly the same. It consists in the pro cess of extracting a saccharine solution from grain, and in converting that solution into a fermented and spirituous beverage. This art, although a perfectly chemical one in nearly all its stages, has not until recent times been in debted to chemistry for any of the improve ments which have been made in its details.
In brewing the various beers, as ale,porter, and table-ale, two kinds of malt are employed, the pale and the brown. The first is used for ales, and for the finer qualities the malt is dried very pale indeed; the brown malt is used for porters and stouts. Roasted or black malt is used as a colouring material, in place of burnt sugar.
The malt is first ground or crushed; and the grist or ground malt being prepared, the next part of the process is the mashing. The mash-tan, or vessel in which this operation is carried on, is usually of wood, varying in size according to the quantity of malt to be wetted, and having two or more taps in the bottom. From one to two inches above this bottom is a false bottom pierced full of small holes, on which the grist is placed; the hot water is then admitted, and the grist is intimately mixed with the water. For this purpose ma chinery is used to stir it about, and cause it to assume a homogeneous consistence. The whole is then allowed to stand at rest for a certain time; and the taps being opened, the infusion, or sweet wort, is allowed to run off into a vessel called the iintlerbaek, whence it is pumped or otherwise conveyed to the copper for boiling. When the wort has run off, the taps are closed, and a fresh quantity of hot water is run on for a second mash. When the whole of the wort is pumped into the copper, the hops are thrown in, and the boiling com mences. For large coppers machinery is used to prevent the hops from settling down and burning. When the boiling is complete, the whole contents of the copper are turned into the hop-back, which is a large square or oblong vessel of wood or iron, having a false bottom for large brewings, and a sieve par tition at the corner for small ones.
As the boiled wort drains from the hops it is allowed to run, or is pumped, into the cool ers. These hops, when sufficiently drained, may be again boiled with a second copper of wort, or with the return wort or table-beer. The coolers are large shallow vessels, placed in as open a part of the brewery as possible, so as to command a free current of air over the whole of their surface: they may be con structed of either wood or iron. Fans and blowers are sometimes used to assist the rapidity of this part of the process. When sufficiently cool, the wort is allowed to run into the fermenting tun.
The wort is next fermented in a large vessel called a gyle, or fermenting tan. As soon as the wort begins to run from tho coolers, and when a sufficient quantity is in the tun, tho yest is added. When the fermentation has arrived at a certain point of attenuation, that is, when a certain quantity of the saccharine matter of the wort has been converted into alcohol or spirit, it is cleansed from the yest; for this purpose it is either run into smaller vessels, such as casks or rounds, or the yesty head is skimmed off from the top ; and this is repeated at intervals until the beer is clean. This operation of skimming is generally con fined to the cleansing of ales. The casks are simply filled with the fermenting beer, and so arranged as to be always kept quite full, with a trough or stillion to catch the yest as it works out at the orifice of these vessels. The beer, being thus cleansed from all the yest, is now either racked directly into casks as for ale, or run into vats prepared for it. On the large scale a large vessel is first used, into which the beer intended to be vatted is allowed to run so as to be perfectly well mixed, and also to deposit a further portion of yest by standing. The beer is by this means also rendered flat, which is necessary for stock or store beer that is to be kept some time before coming into use.