14 



SCIENTIFIC NEWS. 



[March ist, 1SS7. 



SCIENCE IN BREWING. 



IN these days when the names of Pasteur and Huxley are 

 familiar as household words, and the study of the exact 

 changes which take place during fermentation is deemed 

 worthy of our deepest thinkers, it may be interesting to try 

 to realise how far the scientific spirit has permeated the 

 manufacturing mind, and how far the empirical customs of 

 trade are in accordance with the exact laws of science, and 

 consequently promote true economy. The fiscal changes of 

 1880 have done much to develop the technical knowledge of 

 brewers, because, under the new plan, the finished beer is 

 taxed instead of the raw material from which it is made ; 

 unless from want of skill or proper appliances the brewer's 

 produce is below a certain standard, n which case the 

 Government claims the privilege of taxing the raw material. 

 As a consequence, a large number of small brewers who, 

 from want either of capital or knowledge, are unable to 

 compete with their more fortunate opponents, have disap- 

 peared altogether, and the Darwinian law of the survival 

 of the fittest leaves only such as can afford to obtain the 

 necessary technical knowledge. 



But what is this technical knowledge, and what has it done 

 for the good of the people ? Within the remembrance of the 

 present generation all brewing operations were looked upon 

 as secrets, and mysterious recipes were sold, sometimes at 

 fabulous prices, purporting to instruct brewers in the 

 manufacture of any kind of beer.* Now, happily, chemistry 

 teaches the brewer to test the real value of the materials 

 with which he has to work, and with the assistance of the 

 microscope, gives him some knowledge oi those changes 

 which take place between the growth of the raw material 

 and the finished beer. 



The materials necessary to produce pure beer in the 

 present day are water, malted grain, raw grain or sugar, 

 hops, and yeast. For the first of these (water) the chemist 

 can do much. The sources of the water are first ascertained, 

 and it is then tested for traces of recent sewage contamina- 

 tion, and for the presence of organic matter. It needs no 

 very deep knowledge of chemistry to make an analysis of 

 the solids contained in the water, i.e., to find its mineral 

 constituents and the acids with which they are in combina- 

 tion, and by carrying his practical knowledge one step 

 further, the chemist can, in the absence of serious organic 

 impurity, make the water suit the kind of beer which he 

 wishes to brew. 



It has long been known that the London and Dubhn 

 waters are good for stout and porter brewing, and that they 

 are soft waters. The water of the Trent valley, on the 

 other hand, is hard, and is suitable for pale ales ; but the 

 modern technical brewer finds no difficulty in adding to soft 

 water the salts contained in the Burton water, and making 

 it practically the same. Even in some districts where such 

 objectionable compounds as Glauber's salts are present in 

 the natural water, it is by no means a complicated chemical 

 reaction, which, by the addition of another objectionable 

 compound (calcic chloride), renders them both beneficial. 

 Sodic sulphate and calcic chloride give sodic chloride (com- 

 mon salt) and calcic sulphate; common salt being valuable 

 in brewing, as in cooking, to preserve those albuminoid 

 substances which would impair the keeping qualities of 

 the beer. Calcic sulphate is the principal salt that renders 

 the Burton water valuable, and, according to old theories, 

 inimitable. The permanent hardness caused by calcic sul- 

 phate prevents the colouring substances being dissolved, 

 and gives the pale ale now so much preferred. It must be 

 observed, however, that although common salt is a valuable 



* " Brewing No Mystery." By R. Bannister. 



constituent of brewing water, it does not follow that waters 

 containing salt are desirable for brewing purposes ; on the 

 contrary, the presence of the potassic and sodic chlorides 

 is sometimes an indication of sewage contamination. 



It is perhaps with the second group of materials referred 

 to that the brewer's chemist can do the most good, for he is 

 able to ascertain the value and suitability of his material 

 for the purpose required. 



By the legislation of 1880 a brewer may use almost any 

 material from which an alcoholic drink can be prepared ; 

 but experience shows that, except for extreme cheapness, 

 the drink produced from germinated barley is preferable to 

 that made from any other material. The analysis of malts 

 thus becomes an important part of the brewer's work. To 

 ascertain the amount of fermentable sugar or maltose, the 

 dextrin, the nitrogenous matters in the form of soluble 

 albuminoids, and the acid in a decoction (prepared as nearly 

 as possible under the same conditions as the mash in the 

 brewery), has become one of the common processes in a 

 brewer's laboratory. Having ascertained his facts and 

 compared them with the facts ascertained and discovered by 

 physical examination (including the old method of throwing 

 corns into water and finding the percentage of sinkers), 

 comparing the deductions drawn from both, the brewer then 

 knovi^s whether his material is worth buying at any price, 

 and whether it is suitable for a highly alcoholic clean beer, 

 the full-drinking beer generally supplied to the publican, or 

 for the dextrinous beer of Germany. The keeping qualities 

 of the beer are also largely dependent on the excellence of 

 the malt used, and in this, more than in any other respect, 

 the brewer profits by modern science, and knows that he 

 need not have recourse to those numerous panaceas adver- 

 tised in the trade journals, preservatives which promise 

 such wonderful results, and which are as little beneficial to 

 a pure beer as to a pure milk. 



The amount of moisture contained in the malt itself is 

 also important to the brewer, and can readily be ascertained 

 by simple experiment. 



If, however, malt happens to be dear, or the brewer 

 wishes to produce a very strong wort, or from preference of 

 flavour, or any other cause he chooses to use sugar, the 

 chemist can do much to help him. In the case of cane 

 sugar, chemical analysis will show, by very simple tests, 

 how much pure sugar is contained in the material pur- 

 chased. Much of the cane sugar of commerce contains a large 

 proportion of invert or fermentable sugar, and it is, there- _ 

 fore, often valuable to the brewer, although it commands 

 but a low price in the market. This recommendation 

 of cheapness does not apply to such theoretically beautiful 

 preparations as the dextrine-maltose of O'Sullivan, or many 

 saccharines now used ; but these have their advantage in 

 being uniform, and the brewer who does not constantly 

 analyse and watch his malt, may depend on regularity of 

 quality and colour obtained from many excellent glucoses 

 now sold. 



Another legitimate economic substitute for malt is raw 

 grain, and within certain limits the brewer can use the 

 diastase of the malt, not merely to convert the malt itself 

 into a fermentable sugar, but, with its superfluous power, 

 to convert the starch of the raw grain into the same, so that 

 it can be acted upon by the yeast. Whatever the raw 

 grain maj' be, whether rice or maize, the two grains most 

 easily used for this purpose, the beers prepared from them 

 have hitherto been lacking in the empyreumatic flavour ot 

 the malt beers. Beers so flavoured are preferred in 

 England, but the question of there being danger to health 

 in the use of grain, other than malt, is still open to doubt.* 



* Nineteenth Century, January, 1887, p. 131. 



