38 MILLS ASD PETTIGREW ON THE VIIL-On the Steeping of Barley. By EDMUKD J. MILLS D.Sc. F.R.S. “ Young ” Professor of Technica,l Chemistry in Anderson’s College Glasgow and J. PETTIGREW. 1. IN the course of the processes which have for their object the preparation of malt from barley the grain has to undergo a more or less prolonged immersion in water. Various kinds of natural water, some of them of scarcely compatible character are highly esteemed €or the purpose of this steeping. We have not however been able t STEEPIKG OF BARLEY. 3 9 find any published statements * of a detailed description as to the action of water upon barley ; and it appeared to us desirable to make an experimental outline a t least of this undoubtedly complicated phenomenon. Our results are contained in the following para-graphs.2. The barley we employed throughout our investigations was a fine sample of “ chevalier,” grown on limestone soil. Its analysis furnished the percentages recorded below-Moisture . . . . . . . . . . . . . . 13.95 Nitrogen. . 1.87 Ash 2-25 3. The apparatus we employed consisted of a series of glazed cylin-drical earthen pots which were placed on a platform in a tank of water kept constantly running and supplied from the main. Into each pot we introduced 300 grams of barley and 400 cc. of water or some aqueous solution under trial and the whole was covered with a glass plate. Each set of experiments hereafter referred to in the tables was made at one time and under the same conditions. Tem-peratures were taken at noon by direct observation and at midnight by an automatic recording thermometer ; the mean of these tempera-tures is stated in each case.4. It is obvious that in working with a numberof individual grains of barley there may have been some whose outer coatings were injured and which may have yielded extract with more than average rapidity; this is a source of error to which we are undoubtedly, though-as we believe from actual inspection of many of the grains-but very little exposed. Moreover to destroy other small errors we always employed 300 grams of barley-a by no means inconsider-able weight ; and for the sake of obtaining largerresults we prolonged the operation of steeping to 72 hours. I. Calcic Curbonate. ti. A solution of calcic carbonate was made by passing purified car-bonic dioxide through distilled water in which well washed calcic carbonate was suspended.The filtered (saturated) solution contained -0896 per cent. of carbonate. * Xessrs. Lawes and Gilbert in a Parliamentary Report (1866 Reprint 1868) “ On the Relative Values of Unmalted and Malted Barley,” drew attention to the loss in steeping of “ a certain amount of solid matter which consisted of saccharine, nitrogenous and mineral substances” (p. 22). They also found (p. 65) that the barley imparted 391.66 grains per gallon of solid matter (containing 8-62 grains of nitrogen) to the water they had occasion to employ. Our tlianks are due to Dr. Gilbert for a copy of this Report Average temperature 4.8" C. TABLE I. Extract in 100 C.C. 0 *1800 0*1800 0 *1756 0 *1688 0 *1475 Carbonate Residue from Ash from 2:;:- 1 in 100 c.c.1 100 c.c. 1 100 c.c. Nitrogen from 150 C.C. --0 '00546 0 *00742 0.00770 0 '00973 0 '00932 I ,. I1 . . . . 111 . . TV V ,. 0.0896 1 0.4817 0 -3017 0 '0672 0 *4670 0 *2870 0 '0448 0 -4582 0.2830 . O*OOOO* I 0.4015 0 *2540 0.0224 1 0.4440 0.2752 According to these numbers as we diminish :the amount of car-bonate in the water so the extract decreases. The nitrogenous con-stituents of the extract simultaneously increase up to Expt. I V ; but distilled water extracts distinctly less of them than the *0224 solution of calcic carbonate. I I1 IJI . . . . IV v . . . . . . 11. Calcic Xdphate. 6. This salt was prepared by bringing well washed chalk in contact with very dilute snlphuric acid stirring frequently during three weeks and filtering the neutral liquid.Average temperature 11.0". 0'2210 0 *7240 0 -4440 0.1657 0.7470 0 *4296 0-1105 0 *6000 0 -344.0 0.0552 0.5480 0 -3400 0 '0000 0 -5110 0 -2760 TABLE 11. s($$'$e Residue from Ash from Extract in Experi- ment. 1 in c.c. 1 100 C.C. 1 100 C.C. 1 100 C.C. I I--I-- - I- I 0 * 2800 0'3174 0 '2560 0 *2080 0 '2350 Nitrogen from 150 C.C. __I-0 -00546 0 '00616 0 00532 0 *00560 0 -00716 Here also we notice that the extract decreases pari passu with the calcic sulphate from Expt. I1 to Expt. IV. The nitrogen and extract results are greatest of all at Expt. 11. At Expt. V as in the case of the carbonate we get a disproportionate increase of nitrogen in the extract but in addition a greater total extract.The total extract or nitrogen per unit of calcic salts is much greater with calcic sulphate than with carbonate. * Distilled water alone wns hcre used STEEPING OF BARLEY. 41 Buyton Water. 7. Through the good offices of a friend we were able to procure some water which is much used and held in great esteem for steeping purposes in Burton. The water is actually drawn at Lichfield and our sample was turbid. In the following determinations we hare compared it with a water analysed by the Rivers Commission (Report, p. 105) and described as being derived from a deep well in the new red sandstone a t Lichfield. The numbers refer to parts per 100,000, excepting those relating to dissolved gases which represent volumes per cent.TABLE 111. Total solid matter Organic carbon Organic nitrogen Nitric nitrogen Magnesia (MgO) Sulphate (SO,). . Ammonia Silica Lime (CaO) Chlorine. . Hardness (temporary). . , (permanent). . , (total) 32.440 ---0.393 0.656 1.412 10.034 4.450 1-950 7.0 70 11.100 18-700 Dissolved Gases. Ca,rbonic dioxide 3,0211 Nitrogen 3.4747 Oxygen 5.1080 Rivers Commission. 32.060 0.163 0.038 0.003 0.489 ----2.200 9.300 9.000 18.300 The Rivers Commission considered their sample to have been pol-The measured .effects of steeping are as follows :-luted as was doubtless the case with our own. TABLE IV. Residue from Ash from Extract from Nitrogen 1 100 C.C.I 100 C . C . I 100 C.C. jftom 150 C.C. Experiment. I. Burton water 0 -4540 0 *2113 0 *00525 11. Half Burton water 1 0*4100 1 :':;:; 1 0.1893 I lost 111. Distilled water 0 *4132 0 -2230 0 *1902 0 90630 Mean temperature 4.7O 43 hlILLS AKD PETTIGREW OK THE 0'2372 1 0.2156 0.2350 0.2280 0.2274 I 0.2060 Here again the extract decreases as we approach to distilled water. 8. On account of the great importance of this particular water we prepared two waters bearing a partial resemblance to it arid tried with them some steeping experiments. We shall call these liquids '' Factitious Water A " aiid " Factitious Water B." 0*00488 O.OC600 0*00588 Factitious Water A. Assuming the whole of the sulphate in the Burton product to be calcic and all the chlorine to be sodic we compounded this Water A, which was a solution of sulphatc aiid chloride in distilled water in the same proportions as we had fonnd in the Burton supply.Mean temperature 6.9". TABLE V. Experinien t. Residue from Ash from Extract from Nitrogen I 100 C.C. I 100 C.C. 1 100 C.C. 1 from 150c.c. I. Water A ,. 1 0'4382 1 0'2430 1 0'1952 I 0'00448 11. Half water A . . 0.4734 0 *2450 0 -2284 0 *00651 111. Distilled water . . . . 0 -4.132 0 -8112 0 -2020 0 -00483 Thus Water A gives rise on the whole t o more extract and less Water A and distilled water have nitrogen than the Burton sample. about the same effect. * Fuctitiozis Water R. 9. Assuming the temporary hardness to be due to calcic carbonate. and the chlorine to be wholly sodic we prepared this water so as to be a solution in these respects of the same composition as our Burton sample.[The carbonate had been previously dissolved in carbonic water.] Mean temperature 8.0". TABLE VI. Residue from Experiment. 100 C.C. I. Water B . . . . . . . . . . 11. Half water B . . . . . . 111. Distilled water . . . . 0 *4334 1 0 -4528 0 *4630 Like Water A this water takes up most extract and most nitrogen at the half dilution and in nearly the same absolute amount. Water B takes up less nitrogen than distilled water STEEPJSG OF B-\RLEY. 43 Sicpplemeutary Experim elits. 10. We took occasion t o examine several of the liquids in which we had steeped barley. All the solutions and ashes contained phosphates. In the gypsum solution there was an alkaline sulphate.The carbonate solution was slightly acid and gave a precipitate on boiling; the filtrate was not acid and was free from phosphate. 11. The reaction of water in which barley has been steeped is slightly acid and its colour orange or deep orange-yellow. Such water gives a white precipitate with hydric metaphosphnteX in the cold and the filtrate yields a further precipitate on boiling. Water contaiuing calcic sulphate was found to have taken up less colouring water than distilled water and to be lighter when more calcic sulphate was present. One of the gypsum water extracts when heated to boiling gave far less precipitate than the aqueous extract. It furnished no precipitai$e in the cold with hydric metaphosphate.12. Although the amount of orgamic constituents extracted from barley is small seldom exceeding four-tenths per cent. we cannot consider it unimportant. In the chemistry of minute quantities we repeatedly find vast qualitative effects arising from the presence of small masses and depending sometimes for their very occurrence on the condition that the masses are small. May not the absence a t a critical time in the life of the sprouting plant of a little or all of its most soluble albumino'id materially affect the quality of the resulting malt ; when even so apparently indifferent a circumstance as the mode of supplying air to the plant produces a marked alteration of cha-racter ? Aferences and BemarJis. It is obvious from the experiments recorded in (11) that water in which barley has been steeped contains a t least two albuminoid bodies, one of which is thrown down by metaphosphate in the cold the other on boiling.The former of these can be wholly kept back within the grain by the action of a gypsum solution and probably but with rather less efficiency by a chalk solution. 13. The results given in the Tables show that one general effect of a calcic solution is to keep back nitrogenous matter within the grain ; * This reagent which has been for sereral gears employed by one of us as an extremely delicate reagent for albumin is prepared as follows. A quantity of sodic metaphosphate (Madclrell's) is covered with strongly acetified m-ater set aside and occasionally shaken. The clear liquid which must always be kept over the undis-solved sodic salt constitutes the reagent.The metaphosphate has the great advan-tage over the nitrate of not decomposing albumin when boiled clierewitli 44 MILLS AND PETTIGREW ON THE STEEPING OF BARLEY. but the strongest solutions ever likely to be employed in malting are far from entirely preventing the escape of nitrogenous matter. If we glance also a t the " nitrogen " as compared with the " extracts," we cannot fail to perceive that the greater part of the extracts is made up of non-albuminous bodies. I n most cases the stronger the steep-water is in saline constituents the greater is the amount of extract with-drawn acd the less the amount of albuminoid matter allowed to escape. 14. I n comparing Table VI with Table V it will be found that the mineral constituents in Water A probably counterbalance each other's effects so that on the whole Water A acts like distilled water.Water B very closely resembles Watcr A as to extract; but when compared with distilled water it is seen to take out less nitrogen. If we have regard to temperature it is probable that the Burton water takes out more nitrogen than and a t least as much extract as, either gypsum or chalk solution or waters resembling the Burton sample in (I) gypsum + common salt or (2) chalk + common salt. The special esteem in which the Burton sample is held may therefore be due to its nitrate which is well known to hare a highly stimulant action in the germinating of malt -a process which demands much oxygen. 15. The practical value of our experiments will depend very much upon the view taken by maltsters as to the propriety of locking up as far as possible both the non-albuminous and albuminous matters of the grain.Opinions as to the employment of hard or soft waters are at present very much divided. For our own part we lean to the belief that the healthy germination of the seed will be best promoted by keeping within it as much as possible of its natural constituents as is done in ordinary processes of agricultural growth. We have how-ever shown that the usually available reagents for this purpose if employed in the concentrated form take out more extract ; if in the diluted form more albumin. The proper compromise then will be to select a reagent of medium strength; and the best a t present known to us is a gypsum solution containing about one-tenth per cent. It would be easy and probably advantageous to add to this such a pro-portion of calcic nitrate as would correspond to a few tenths per 100,000 of nitric nitrogen. Finally the question naturally occu1's, Why not use sufficient water just to saturate the grain and no more? If this plan were adopted (and we are unaware of any practical difi-culties in the way) the softest natural water might be employed with success and not a trace of its constituents would be lost as in the ljest existing practice to the germinating grain