The art of preparing ale or beer. The materials commonly used for this purpose are malted barley and hops. The ingredients serve as the basis of all ale and beer, and, indeed, are the only ones permitted by law; but most public brewers, in addition, make use of a variety of other articles to improve the appearance of the beer, or to suit the taste of their customers. Each brewer has his own recipes for these purposes, which he endeavours to keep secret; but many of the substances so employed are known to be of a very noxious nature. The brewing of beer of all kinds is conducted by the same general process; the principal variations in it depend upon the scale upon which the operation is carried on; we shall therefore first give an outline of the process as adapted to private families, and afterwards a description of the manner in which the operation is conducted in public breweries on a large scale. The method usually followed in brewing on a small scale is as follows: The malt coarsely ground, or rather crushed, is strewed evenly over the bottom of a broad tub, called the mash-tub, which is furnished with a wooden spigot or cock, near the bottom, over the inner end of which is fitted a strainer of basket-work to keep out the grains.
A quantity of water, proportioned to the quantity of malt and the strength intended for the beer, is then boiled in a copper, and afterwards allowed to cool down to about 170° Fahr.; this is then poured gradually over the malt, which is stirred all the time with a sort of rake of a triangular form. When the whole of the water has been poured on the malt, the tub is covered with matting or sacking to retain the heat, and the malt is stirred from time to time. When the water has been two hours on the malt, it will have dissolved the greatest portion of the saccharine matter of the grain; the solution is called wort, which is drawn off into a tub beneath the mash-tub, and another portion of water, less than the first, and at about 180° Fahr., is poured over the malt. After this has stood for about an hour, it is likewise drawn off, and may either be mixed with the former worts, or kept separate to form an inferior description of beer. A third water is sometimes given, which should be at 190° Fahr. When the whole of the saccharine matter is extracted from the malt, the remainder is called grains, and is used for feeding pigs.
The worts are then removed to the copper, and either boiled with the hops, in the proportion of l1/2 lb. of hops to a bushel of malt, or (which is a better way) an infusion of hops, previously prepared at a gentle heat, is added to the worts, and the whole is boiled rapidly until the liquor parts, as it is called, that is, the mucilaginous parts which were suspended in the liquor, and rendered it turbid, separate from it, appearing like a quantity of white worms swimming through the liquor, and if a small portion of it be taken in a glass, the liquor quickly becomes clear, and a thick sediment is precipitated. The liquor is then poured through a coarse strainer (to separate the hops) into shallow tubs, placed, if possible, where there is a current of air, in order to cool as rapidly as possible; and when it has come down to about 60° Fahr, it is collected into the fermenting tun, and the yeast (first mixed with a small quantity of worts) is added to the liquor, and well incorporated with it by stirring it with a new birch broom; the tun is then covered up with cloths, and the temperature of the room maintained a little above 60°.
In a short time fermentation commences, forming a white head on the surface of the worts, and a large portion of carbonic acid gas is evolved, accompanied by a strong vinous odour. As soon as the head begins to fall, the beer is removed into casks, with the bungs left out for the escape of the yeast, which comes over in considerable quantities; the casks being replenished at intervals to compensate for the portion of beer which is carried over with the yeast; and when the yeast ceases to come over, the casks are first lightly, and afterwards securely, bunged up for future consumption.
We shall now proceed to describe the process as usually conducted in a brewing establishment on a moderately large scale. The first operation is the proper grinding, or rather crushing of the malt; this is sometimes performed between mill-stones, in the manner in which corn is ground, only the stones are set rather further asunder; but of late years it has become more common to crush the malt between two cylinders. The malt is then suffered to lie some time in a bin or cool room, to mellow, as it is called. Grist thus exposed to the air it is said requires less mashing, and the strength of the malt is more perfectly obtained. Mashing in the large way is usually performed in a circular wooden or cast iron vessel, called the mash tun, and furnished with a false bottom perforated with holes. Between the real and false bottom, which are generally a few inches asunder, are two side openings; to one is fixed a pipe for conveying hot water into the tun, and to the other a pipe and cock for discharging the liquor into another vessel. The mashing is performed by machinery invented for that purpose. These machines are variously constructed; the following is one of the most approved description.
Upon this axis is a bevelled wheel, which turns a horizontal axis extending from the centre to the circumference of the tun. This axis has four wheels upon it, over which pass four endless chains, which also pass round wheels on a horizontal axis near the bottom of the tun. Upon the endless chains are fixed iron rakes, which, as the wheels revolve, bring up the malt from the bottom of the tun to the top. These also receive a slow progressive motion round the tun by the following means: the outer ends of these axes are supported in bearings in a vertical frame, which rises to the top of the mash tun, and is braced to a collar on the vertical shaft. On the top of this frame is a bearing, to support the outer extremity of a horizontal shaft, on the inner end of which shaft is a bevelled wheel, which works in another bevelled wheel on the vertical shaft. The horizontal shaft, by means of another bevelled wheel fixed at its outer extremity, gives motion to an endless screw, supported by a carriage attached to the vertical frame, and the endless screw acting upon a ring of teeth fixed upon the curb of the mash tun, causes the mashing apparatus slowly to perform the circuit of the tun.