The two great classes of malt liquor above referred to, are, independently of mere differences of strength, excellence, and commercial value, practically subdivided into an almost infinite number of varieties. Every county, every town, and almost every brewer, is distinguished by the production of a different-flavoured beer, readily perceived, and highly appreciated by their respective votaries. These differences may be traced to—variations in the quantity and quality of the materials employed in their manufacture—the temperature of the water used for mashing—the duration of the boiling—the temperature at which the fermentation is conducted, and the extent to which it is carried, together with numerous other circumstances, which, though usually of an accidental and uncertain character, are nevertheless sufficient to affect the flavour and quality of a brewing. Among these, those depending on the condition of the building, the locality, the apparatus, the water, the management, &c., are not the least important. In general, however, when the same quantity and quality of materials are employed, and the same time allowed for the maturation of the liquor, the chief causes of this diversity will be found to depend on the water used in the brewing, and the method followed in the preparation of the malt. Thus, Bavarian, Scotch, and Burton ales differ in style from other ales chiefly from being fermented at a lower temperature, and from the water employed in the brewing being that usually denominated ‘hard,’ whilst porter and stout differ from all these because they are brewed from a mixture of pale and roasted malt. It is from causes like these, though apparently trivial, that the many varieties of malt liquor met with, at the present day, originate.
The per-centage in English beers of malt extract (dextrin and sugar glucose) is least in bitter, and highest in the sweet ales. The hop extract (lupulin and hop resin) is in much smaller amount.
The alcohol varies considerably, as does also the free acidity.
The albuminous matter in most beers does not average more than 0·5 per cent.
The salts, which consist of alkaline chlorides and phosphates, and some earthy phosphates, average 0·1 to 0·2 per cent. Ammoniacal salts are found in small quantities. Caramel and assamar are found in the dark beers and porters. Carbonic acid is always more or less present. The average is 0·1 to 0·2 parts by weight per cent., or about 13⁄4 cubic inches per ounce. Volatile and essential oils are also present.
Parkes says, “Adopting means numbers; one pint (20 oz.) of beer will contain—
| Alcohol | 1 | ounce. | |
| Extractive (dextrin), sugar, &c. | 1·2 | ” | (534 grains). |
| Free acid | 25 | grains. | |
| Salts | 13 | ” |
The following beer analyses are given by Professor Wanklyn:
Bass’s bottled bitter ale contains in 100 cubic centimètres:
| 5·3 | grams of | alcohol. |
| 5·52 | ” | organic residue. |
| 0·36 | ” | ash. |