The composition of beer naturally varies according to the kind of grain from which it is made and the process of fermentation employed. The chief ingredients are alcohol, carbonic acid, sugar (maltose), dextrine, the oil and bitter principle of hops (lupuline), albuminoids, lactic, acetic, succinic and propionic acids, inorganic salts, and traces of glycerine. The term “extract” is applied to the non-volatile constituents, which include the sugar, dextrine, albuminoids, ash, etc. The foregoing table, collated from the analyses of various chemists, gives the general composition of some of the best known brands of malt liquor, as well as the minimum and maximum proportions that have been found.
| Variety. | Specific Gravity. | Carbonic Acid. | Alcohol (by weight). | Extract. | Albuminoids. | Sugar. | Dextrine. | Acid. | Ash. | Phosphoric Acid. | ||
| per cent. | per cent. | per cent. | per cent. | per cent. | per cent. | per cent. | per cent. | per cent. | ||||
| Porter | 1·0207 | 0·16 | 5·4 | 6·0 | 0·83 | .. | 7·72 | 0·24 | 0·40 | .. | ||
| Scotch ale | .. | 0·15 | 8·5 | 10·9 | 0·77 | 0·34 | 2·50 | 0·19 | .. | .. | ||
| Burton ale | 1·0106 | .. | 5·9 | 14·5 | 0·57 | .. | 3·64 | 0·32 | .. | .. | ||
| Munich (Salvator) | 1·0129 | 0·18 | 4·6 | 9·4 | 0·67 | .. | .. | .. | .. | .. | ||
| „ (Bock) | 1·0118 | 0·17 | 4·2 | 9·2 | .. | 0·80 | .. | .. | 0·22 | 0·024 | ||
| „ (Schenk) | .. | .. | 3·8 | 5·8 | .. | .. | 6·17 | 0·14 | .. | .. | ||
| „ (Lager) | 1·0110 | 0·15 | 5·1 | 5·0 | 0·83 | 0·35 | .. | 0·20 | 0·21 | .. | ||
| Berlin | .. | .. | 3·1 | 5·8 | .. | .. | .. | .. | 0·21 | .. | ||
| „ (Tivoli) | .. | .. | 4·35 | 5·14 | .. | .. | .. | 0·23 | 0·19 | .. | ||
| Erlanger | .. | .. | 4·56 | 4·81 | .. | 0·40 | 1·44 | .. | 0·48 | .. | ||
| Thüringer (common) | .. | .. | 2·00 | .. | .. | 0·31 | 7·71 | .. | .. | .. | ||
| Culmbacher | 1·0228 | .. | 4·00 | 7·38 | 0·53 | .. | .. | 0·16 | .. | .. | ||
| American lager, average 19 samples | 1·0162 | .. | 2·78 | 6·05 | .. | 1·52 | .. | 0·19 | 0·305 | 0·105 | ||
| American ale | 1·0150 | .. | 4·69 | 6·50 | 0·74 | 4·96 | .. | .. | 0·253 | 0·080 | ||
| American lager, 474 samples |  | maximum | 1·0370 | .. | 8·99 | 9·54 | .. | .. | .. | .. | 0·46 | 0·166 |
| minimum | 0·999 | .. | 0·68 | 1·28 | .. | .. | .. | .. | 0·10 | 0·028 | ||
| According to König | | maximum | 1·034 | 0·500 | 7·3 | 11·24 | 1·98 | 2·45 | 7·85 | 0·40 | 0·48 | 0·09 |
| minimum | 1·0100 | 0·100 | 1·00 | 2·60 | 0·02 | 0·10 | 1·46 | 0·08 | 0·14 | 0·02 | ||
The composition of beer ash is evidently affected by the character of the water used in the brewing process. Blyth gives the following as the average composition of the ash of English beers:—
| Per cent. | |
| Potash | 37·22 |
| Soda | 8·04 |
| Lime | 1·93 |
| Magnesia | 5·51 |
| Ferric oxide | traces |
| Sulphuric acid | 1·44 |
| Phosphoric acid | 32·09 |
| Chlorine | 2·91 |
| Silica | 10·82 |
The following results were obtained by the writer from the analysis of the ash of American lager beer of fair quality:—
| Per cent. | |
| Silica | 9·97 |
| Alumina and ferric oxide | 0·46 |
| Lime | 3·55 |
| Magnesia | 7·27 |
| Soda | 13·81 |
| Potassa | 19·59 |
| Sulphuric acid | 3·25 |
| Chlorine | 4·40 |
| Phosphoric acid | 37·70 |
| 100·00 | |
| Percentage of ash | 0·274 |
Strictly speaking, normal beer consists solely of the product of malt and hops, and the presence of any ingredients other than these should be regarded as an adulteration. It is maintained by brewers, and with justice, that the term “malt” is not necessarily restricted to barley, but includes other varieties of malted grain, such as wheat, corn, and rice. The old English law, while permitting the addition of wholesome bitters, prohibits the use of various other substances, but in the United States, no legal definition of pure beer has, as yet, been formulated, and the necessity for such a measure is being experienced.[70] The past literature of beer adulteration makes mention of very numerous substances which, in former times, have been resorted to as admixtures. Among these the following are the most prominent:—
1st. Artificial bitters.—Picric acid, picrotoxine, aloes, gentian, quassia, and wormwood. Several years ago the author had occasion to examine two samples, imported under the name of “hop substitutes,” both of which proved to consist of salicine, the bitter principle of the willow. The fruit of the hop tree (Ptelea trifoliata), has also been employed as an artificial bitter for beer.
2nd. Flavourings.—For flavouring purposes, cayenne pepper, “grains of paradise,” cloves, orris root, coriander seeds, the oils of anise, nutmegs, and carraway, are stated to have been used.