The factory should always be well provided with gas-producing materials, stored in the most convenient place. Acid cisterns should be kept carefully covered in order to prevent accidents, and the contents should be handled only by those whose duty it is to manipulate the supplies. The car bonate, of whatever description, and the vitriol must be of the purest ; this is another point upon which much depends. Samples of the former ought to contain no foreign salts, and especially no salts of iron or earthy oxides. The acid ought to have been carefully rectified ; the use of common vitriol imparts to the water a nitrous taste which can frequently be detected in the produce of inferior makers.
Beer. (Fa., Biere ; GER., Bier.)—Beer is a fermented liquor produced from malted barley, and flavoured by the addition of hops. Different varieties of this liquor are known as "bitter ale," " mild ale," " porter," and " stout," according to their flavour, strength, or colour, and to the nature and quantity of ingredients used in their production. Beer and porter are manufactured in enormous quantities in England, comparatively little being made anywhere else. Tho produce of some of the largest breweries, and particularly those of Burton-on-Trent, is famed throughout the whole of the civilized world. The article itself and its peculiarities are too well known to need description.
The materials employed in brewing are, in the main, water, barley, and hops, and since much care is requisite in making selection of the ingredients, it will be necessary to describe minutely those kinds of each which are best adapted to the requirements of the brewer. The process by which beer is brewed from these may bo divided into two operations : malting and brewing. Full particulars of the operation of malting, or of converting barley into malt, and of the apparatus employed, will be found in the article on Malt, and hence it will be only necessary to point out here tho nature of the changes undergone by the barley in its conversion. The subsequent processes of brewing will be treated in minute detail.
Water.—A oonstant, unfailing supply of good water is indispensable in brewing; though what really constitutes good water is a point upon which many brewers and chemists have long been at issue. Some rest their faith upon a soft water; others will use only the hardest water they can get ; while others, again, are quite indifferent, and will use either. It is now, however, a generally accepted fact that water for brewing should not contain organic matter, but a considerable quantity of inorganic or saline constituents, these varying in nature and quantity, according as the beer to bo made is required for keeping or for immediate consumption. English brewers are now agreed that the water should contain much carbonate and sulphate of lime. The former of these two ingre dients is the most necessary, but they should both be present in the water from which ale is to be made ; water used in brewing porter may contain the carbonate alone. For the best ales,
tho proportions seem to be from 10 to 20 grains a gallon of eaoh. The excellence of the ales made by the Burton brewers is doubtless due to the quality of the water used by them ; it is very hard, and oontains, as will be seen from the analyses given below, a large proportion of alkaline sulphates and carbonates ; this is the best argument that oan be brought forward in favour of the use of hard water. The supply is derived entirely from springs, and uot, as some suppose, from the river Trent. It has also been urged, as an advantage, that hard water increases the quantity of saccharine matter held in the wort, thus heightening the flavour and preventing it from be coming acid. The following tables represent analyses of the waters used by several of the largest brewing firms in the United Kingdom :— When nothing but soft water can be had, it is possible to imitate the Burton water very closely by the addition of sulphate of lime, and the chlorides of sodium, magnesium, and calcium. These salts are added in the water cisterns or coppers. Gypsum, or sulphate of lime, which is sufficiently soluble, is used in lumps, one or two inches square ; when added to the hot-water coppers, it is employed in a fine powder.
Bstrley.—The selection of the barley used hy the brewer calls for the exercise of much skill and judgment ; unless the quality be of the very best, it is impossible to obtain good malt, and without good malt, it is useless to attempt to make good beer. A. practised brewer can judge of the quality of his barley by its appearance. The heaviest, if in good condition, is always the best ; the grains should be plump, and of a pale-yellow colour ; they should have a thin skin, aud a free, chalky fracture. That which has been grown in a light soil and harvested early, is also preferable. It is of much importance to the monster that barley be lodged in the stack for few weeks before being thrashed, in order to allow the moisture from the soil to dry off before it comes into his hands. If this is done, the operation of drying in the kiln is avoided. In moist districts, however, where tho grain never gets thoroughly dried, this process must invariably be had recourse to ; the temperature of the kilns must never be allowed to rise above 50° (120° F.). Care must be taken to avoid breaking or crushing the grains of malting barley, so as to minimize the chances of its becoming mouldy in the subsequent processes of malting, a contingency which should be avoided in every possible way. It should also be screened before steeping, in order that the grains may all be of equal size on the spireing floor. These remarks, of eourse, apply only to the brewer who is, as he ought always to be, his own maltster.