4. Upon agitating 20 c.c. of the suspected beer in a test-tube with 10 c.c. of amylic alcohol, allowing the mixture to remain at rest, and then removing the amylic alcohol, a solution is obtained which contains any picric acid present in the sample treated. It is evaporated to dryness, the residue dissolved in a little warm distilled water, and the aqueous solution submitted to the following tests:—
(a) To one portion a concentrated solution of potassium cyanide is added; in presence of picric acid, a blood-red colour is produced, due to the formation of iso-purpuric acid.
(b) A second portion is treated with a solution of cupric-ammonium sulphate; if picric acid be present, minute greenish crystals of cupric-ammonium picrate will be formed.
(c) To a third portion, a little ammonium sulphide, containing free ammonium hydroxide, is added; in presence of picric acid, picramic acid is produced, the formation of which is accelerated by the application of heat, and is made evident by the appearance of an intensely red colour.
The detection of cocculus indicus, or its poisonous alkaloid, picrotoxine, may be effected by first agitating the beer with plumbic acetate, filtering, removing the lead from the filtrate by means of sulphuretted hydrogen, and again filtering. The filtrate is first boiled, then carefully evaporated until it possesses a thickish consistency, when it is shaken up with animal charcoal, which is afterwards brought upon a filter, washed with a very little cold water, and dried at 100°. The picrotoxine possibly present is then extracted from the animal charcoal by boiling it with strong alcohol, from which the alkaloid separates on evaporating the solution, either in quadrilateral prisms or in feathery tufts.
Again reverting to beer adulteration, Prof. H. B. Cornwall has lately made an interesting report in this regard.[82] Several years ago, in reply to a circular issued by the “Business Men’s Moderation Society of New York City,” the “Association of United Lager Beer Brewers” asserted that the only substitutes for barley malt employed were corn starch, corn meal, rice, glucose, and grape sugar, no artificial bitters being used. The addition of glucose and grape sugar, the association stated, was not necessarily on account of economy, but had for its object an increase in the strength of the wort, without resorting to concentration and the production of beer of desirable flavour and colour. Rüdlinger[83] denies that beer is subjected to injurious adulteration in Germany. He states substantially as follows: “Cases of sickness, frequently claimed to be caused by the beer, are due either to excess or to the consumption of the new and incompletely fermented beverage. It has been affirmed that brewers often economise in hops by the use of other and deleterious bitters, and that picric acid and strychnine have been employed for this purpose. Nonsense, once written, is frequently copied by hundreds, and in this way circulates among the masses. The maximum amount of hops used in beer is really inconsiderable, and, there exists no necessity for resorting to foreign substitutes, even in seasons when the price of hops is abnormally high, since the proportion of this ingredient could be slightly decreased without incurring the danger of detection which would follow the use of artificial bitters.” On the other hand, it is certain that, in past years, such injurious additions as cocculus indicus, picric acid, aloes, etc., have actually been discovered by chemists of high standing in bitter ale and other forms of beer. A. Schmidt,[84] asserts that glycerine, alum, and sodium bicarbonate are added to beer, and states that beer, poor in extractive and alcoholic constituents, is liable to become sour, a defect which is remedied by the use of alkalies and chalk, the resulting disagreeable taste being disguised by means of glycerine. The same authority deprecates the use of glucose on account of the absence of nutritious albuminoids and phosphates in this substance. It would certainly appear obvious that the direct addition of starch-sugar to the wort, which results in augmenting the alcoholic strength of beer without correspondingly increasing the proportion of valuable extractive matter, is of doubtful propriety. Grains are less open to this objection. Of these, maize is generally regarded as the best substitute for barley malt, both on account of its similarity in composition and its cheapness. The International Congress of Medical Sciences, held at Brussels in 1875, adopted the following resolutions:—
1. Genuine beer should be made from grain and hops.
2. No other substances should replace these, either wholly or partially.
3. All substitutes should be considered as adulterations, and should come under the penalty of the law, even if not deleterious to health.
The German Brewers’ Association, at its Frankfort meeting, defined wholesome beer as the produce of malt, hops, yeast, and water with a partial substitution of the malt by starch meal, rice, maize, and glucose, and regarded the use of some malt substitutes as permissible on scientific and hygienic grounds. It recommended, however, that, in case such substitutes are employed, the beer so prepared should be designated by a distinctive name, such as “rice beer,” “sugar beer,” etc.