Method of detecting the Adulteration of Beer
The detection of the adulteration of beer with deleterious vegetable substances is beyond the reach of chemical analysis. The presence of sulphate of iron (p. 134) may be detected by evaporating the beer to perfect dryness, and burning away the vegetable matter obtained, by the action of chlorate of pot-ash in a red-hot crucible. The sulphate of iron will be left behind among the residue in the crucible, which when dissolved in water, may be assayed, for the constituent parts of the salt, namely, iron and sulphuric acid: for the former, by tincture of galls, ammonia, and prussiate of potash; and for the latter, by muriate of barytes.80
Beer, which has been rendered fraudulently hard (see p. 148) by the admixture of sulphuric acid, affords a white precipitate (sulphate of barytes), by dropping into it a solution of acetate or muriate of barytes; and this precipitate, when collected by filtering the mass, and after having been dried, and heated red-hot for a few minutes in a platina crucible, does not disappear by the addition of nitric, or muriatic acid. Genuine old beer may produce a precipitate; but the precipitate which it affords, after having been made red-hot in a platina crucible, instantly becomes re-dissolved with effervescence by pouring on it some pure nitric or muriatic acid; in that case the precipitate is malate (not sulphate) of barytes, and is owing to a portion of malic acid having been formed in the beer.
But with regard to the vegetable materials deleterious to health, it is extremely difficult, in any instance, to detect them by chemical agencies; and in most cases it is quite impossible, as in that of cocculus indicus in beer.
METHOD OF ASCERTAINING THE QUANTITY OF SPIRIT CONTAINED IN PORTER, ALE, OR OTHER KINDS OF MALT LIQUORS.
Take any quantity of the beer, put it into a glass retort, furnished with a receiver, and distil, with a gentle heat, as long as any spirit passes over into the receiver; which may be known by heating from time to time a small quantity of the obtained fluid in a tea-spoon over a candle, and bringing into contact with the vapour of it the flame of a piece of paper. If the vapour of the distilled fluid catches fire, the distillation must be continued until the vapour ceases to be set on fire by the contact of a flaming body. To the distilled liquid thus obtained, which is the spirit of the beer, combined with water, add, in small quantities at a time, pure subcarbonate of potash (previously freed from water by having been exposed to a red heat,) till the last portion of this salt added, remains undissolved in the fluid. The spirit will thus become separated from the water, because the subcarbonate of potash abstracts from it the whole of the water which it contained; and this combination sinks to the bottom, and the spirit alone floats on the top. If this experiment be made in a glass tube, about half or three-quarters of an inch in diameter, and graduated into 50 or 100 equal parts, the relative per centage of spirit in a given quantity of beer may be seen by mere inspection.
Quantity of Alcohol contained in Porter, Ale, and other kinds of Malt Liquors.81
| One hundred parts, by Measure, contained. | Parts of Alcohol, by Measure. |
|---|---|
| Ale, home-brewed | 8,30 |
| Ale, Burton, three Samples | 6,25 |
| Ale, Burton82 | 8,88 |
| Ale, Edinburgh82 | 6,20 |
| Ale, Dorchester82 | 5,50 |
| Ale, common London-brewed, six samples | 5,82 |
| Ale, Scotch, three samples | 5,75 |
| Porter, London, eight samples | 4,00 |
| Ditto, Ditto83 | 4,20 |
| Ditto, Ditto83 | 4,45 |
| Ditto, Ditto, bottled. | 4,75 |
| Brown Stout, four samples | 5 |
| Ditto, Ditto83 | 6,80 |
| Small Beer, six samples | 0,75 |
| Ditto, Ditto84 | 1,28 |
Footnotes
48 See pages 119, &c.
49 Child, on Brewing Porter, p. 7.
50 Child, on Brewing Porter, p. 16.
51 Ibid. p. 16.
52 “Minutes of the Committee of the House of Commons, to whom the petition of several inhabitants of London and its vicinity, complaining of the high price and inferior quality of beer, was referred, to examine the matter thereof, and to report the same, with their observations thereupon, to the House. Printed by order of the House of Commons, April, 1819.”
53 56 Geo. III. c. 2.
54 Copied from the Minutes of the Committee of the House of Commons, appointed for examining the price and quality of Beer.—See pages 18, 29, 30, 31, 36, 43.
55 The average specific gravity of different samples of brown stout, obtained direct from the breweries of Messrs. Barclay, Perkins, and Co. Messrs. Truman, Hanbury, and Co. Messrs. Henry Meux and Co. and from several other eminent London brewers, amounted to 1,022; and the average specific gravity of porter, from the same breweries, 1,018.
56 2 Geo. III. c. 14, § 2.
57 59 Geo. III. c. 53, § 25.
58 Copied from the Minutes of the Committee of the House of Commons, appointed for examining the price and quality of beer, p. 19, 29, 36, 37, 43.
59 See Minutes of the Committee of the House of Commons for reporting on the Price and Quality of Beer, 1819, p. 29.
60 7 Geo. II. c. 19, § 2.
61 See List of Publicans prosecuted and convicted for mixing table beer with strong beer, &c. p. 129.
“Alum gives likewise a smack of age to beer, and is penetrating to the palate.”—S. Child on Brewing.
62 Copied from the Minutes of the Committee of the House of Commons, appointed for examining the price and quality of beer, p. 38.
63 See Mr. Carr’s evidence in the Minutes of the House of Commons, p. 32.
64 42 George III, c. 38, § 12.
65 See Minutes of the House of Commons, p. 32.
66 Copied from the minutes of the Committee of the House of Commons, appointed for examining the price and quality of Beer, 1819, p. 29, 36, 43.
67 See the Parliamentary Minutes, p. 94.
68 Mr. Barclay has not specified the relative proportions of brown stout and of bottling beer which are introduced at such an augmentation of expense.
69 Mr. Child, in his Treatise on Brewing, p. 23 directs, to make new beer older, use oil of vitriol.
70 Copied from the Minutes of the Committee of the House of Commons appointed for examining the price and quality of beer, p. 29, 36.
71 The deleterious effect of Cocculus Indicus (the fruit of the memispermum cocculus) is owing to a peculiar bitter principle contained in it; which, when swallowed in minute quantities, intoxicates and acts as poison. It may be obtained from cocculus indicus berries in a detached state:—chemists call it picrotoxin, from πικρός, bitter; and τοξικόν poison.
72 See Minutes of the House of Commons, p. 28, 36.
73 Messrs. Barclay, Perkins, and Co.—Truman, Hanbury and Co.—Reid and Co.—Whitbread and Co.—Combe, Delafield, and Co.—Henry Meux, and Co.—Calvert and Co.—Goodwin and Co.—Elliot and Co.—Taylor and Co.—Cox, and Camble and Co.
See the Minutes, before quoted, p. 32.
74 Ibid. p. 58.
75 A partner in the brewery of Messrs. Whitbread and Co.
76 Minutes of the House of Commons, p. 104.
77 Minutes, before quoted, p. 22.
78 Minutes of the House of Commons, p. 40.
79 Minutes of the House of Commons, p. 32.
80 See a Treatise on the Use and Application of Chemical Tests, 3d edition; Tests for Sulphuric Acid, &c.
81 Repository of Arts, No. 2, p. 74.—1816.
82 Copied from Professor Brande’s Paper in the Philosophical Transactions, 1811, p. 345.
83 Result of our own Experiments, see p. 127.
84 Professor Brande’s Experiments.