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Originally appearing in Volume V17, Page 507 of the 1911 Encyclopedia Britannica.
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IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIII,IIIIIIIIIIIIiIIIIIIIIIIIIII f.IIII~:i111IIhIll:flll = v 1111iiPlIP 11.11141111 II la II !MI I la MINI ii y yi (rri -I °l LAI Ground Lour/ Figure 8 shows a longitudinal section of Messrs Watney, Combe, Reid & Co.'s zoo quarter malting at Mortlake. The barley is carried to the top of the building by the elevator A, where the screening and dressing machinery is situated. After leaving these machines the grain is conveyed on bands to the barley floors B and C. The floor C contains also the steeping cisterns. The six working floors are D, E, F, G, H, K. The floors are ventilated by louvres, .N, N, N. The cisterns are connected to the floors by means of plugs. The " pieces," as they are termed, of germinating barley are gradually worked along the floors to the kilns M, M, on to which they are loaded by rotary bands. The fire-places 0, 0, are arranged so that the draught may be easily controlled. The hot air and products of combustion pass up the shafts P, P, to the hot-air chamber R, R, where they strike the baffle plates S, S. These plates disperse the hot air and gases evenly beneath the kiln floors T, T, through the green malt. After drying and curing, the malt is allowed to cool and is then carried by bands to the floor U, where by suitable machinery the coombs or rootlets are removed. The finished malt is stored in the bins V, V, V. On arrival at the malting the barley has to be put through the following operations seriatim: receiving, hoisting and weighing, rough screening, drying and sweating, storing until required for use, screening, grading and removing broken corns, steeping, couching, flooring, withering, drying and curing, dressing and polishing, storing, weighing, sacking and discharging the finished malt. In sweating barley the temperature should not be allowed to rise above 120° F.; it is usually conducted at too° F.; and subsequently the barley should be stored for some weeks before it is are conical and constructed of iron; they have arrangements at the apex of the cone, the lower portion, for discharging the grain by gravitation. The steeping period ranges from 48 to 70 hours; it varies according to the kind of barley, and .the time of the year. In some of the older maltings there are no arrangements for heating the steep water, and in the winter steeping has occasionally to be performed with water at a temperature near its freezing-point. Steeping should be carried out at a temperature as near as possible to 550 and not higher than 6o° F. The usual practice is to fill the cistern up to a certain height with water and throw the barley into it, stirring it until it is about level; the heavy corns will then sink directly to the bottom, whilst the light corns and refuse float on the surface and may be skimmed off. During the time the barley remains in the cistern it is usual to change the steep water two or three times, generally at intervals of twelve hours or tides. The advantage of this is not merely to keep the grain fresh and sweet, but to bring it into contact with the air during the time it is taking up water. Aeration of the steep has long been recognized in Germany as promoting germination, and several arrangements are on the market enabling air to be passed through the grain while it is in the cistern. It has been recommended by Graham, Stopes, Moritz and Morris, and experimental evidence as to its beneficial effects has been published by Windisch, Bleisch, Will, and Baker and Dick. When the corn is steep ripe it contains some 6o% of water. Steeping does not consist, however, merely in the MALT the grain will begin to sweat, and the rootlets will be thrown out suddenly and unevenly. As a rule, under these circumstances, the rootlets will be long and thin, when they are said to be " wild." A piece which has been allowed to get into this condition must at once be spread thinner. If the sweating has not continued long, the harm done may be confined to increased loss by respiration. The young floor is usually turned with a plough twice during twelve hours, and it may be forked between whiles, but no hard and fast rule can be laid down as to when this is necessary; it must be left to the maltster's judgment, as it depends entirely on what is going on within the grain. The object of turning is in the first place to aerate the grain and freshen it, secondly to check excessive rise of temperature, and thirdly to promote evenness of growth. Too frequent turning is not to be advised. After remaining four days on the young floor three or four rootlets should have appeared, and the acrospire should have begun to grow up the back of the corn. The apple-like odour of the piece then gives place to one resembling that of the common rush, and this should continue the whole time that the malt remains on the floor. On the fifth day the piece is next moved to No. 2 position, a stage nearer the kiln. It is here that sprinkling is resorted to when necessary. The amount of sprinkling and the time it is given cannot be exactly prescribed. The amount may vary from two to five gallons per quarter, and it should only be given when the rootlets, which ought to be short and curly, and five or more in number, show signs of losing their freshness. If an excessive amount of sprinkling be given forced growth ensues. It is preferable not to add the whole of the water at one time, but to divide it over two lots; and immediately after the piece has been sprinkled it should be thoroughly and carefully mixed, otherwise some of the grain will receive an undue proportion of water. When all the sprinkling water has been given to the piece, which as a rule should not be done later than at the sixth or seventh day of flooring, the temperature should be kept down to about 55° F. by turning. Too frequent turning may, however, detach the rootlet, and it may cause the grain to lose its vitality prematurely, so that growth of the acrospire stops. By about the eighth day of flooring the acrospire should be about three-quarters up the corn. After this the germinating corn is moved forward to No. 3 piece, which is at first spread as thinly on the floors as in the previous pieces. Here it gradually dries and incipient withering of the rootlets sets in. The only treatment which is now given to the grain is to heap it up thicker and thicker by degrees until it is ready for loading on the kiln. This increase in thickness of the piece (now called the old piece) should not be too sudden, especially if the grain be fresh in appearance and contain a large quantity of water. When the piece is thickened up to say xo in. in depth, while it is in a very moist condition, heating and sweating take place, with additional growth of acrospire and rootlet. Under such forcing conditions a large production of sugar and degradation of the proteins will take place. When, however, the moisture has been gradually reduced before thickening up, the rootlet dies off; and al-though increase of temperature may occur, this is accompanied by little or no further growth of the acrospire, action being con-fined to the mellowing of the grain by the enzymes. When the malt is ready for loading on the kiln it should be possible to break down the contents of each corn between the thumb and finger. Opinions differ as to what the final temperature on the withering floor should be. If the moisture content of the malt be about 50 %, the piece must be kept thin to avoid sweating. But under these conditions mellowing does not occur, hence the necessity of reducing the moisture content gradually after the last sprinkling water has been given. When the process has been conducted properly the temperature of the old piece may be allowed to rise as high as 700 F. during the six hours previous to loading. The moisture content of the green malt when loaded should not be much above 40 %. The endosperm of green malt which is ready for the kiln should be soft and mealy, and should not exude moisture when imbibition of a certain amount of water; in order to bring about germination this water must remain within the corn a certain length of time. Thus, although it is quite possible to force the necessary amount of water into the grain in less than the 48-70 hours usually taken up by the steeping process, the grain is not steep-ripe until certain changes initiated by the water have taken place, and these require time for their completion. The following average data are useful to remember in connexion with the steeping process: Amount of water in steep-ripe barley (about) 6o%. Matter removed from barley during steeping (about) 1•5 Increase in volume of barley due to water absorption (about) 18—20 %. There has been much discussion as to the influence of saline matters in water on the steeping process. The late Professor Lintner stated that common salt in water tended to extract the nitrogenous constituents of the grain, but impeded its germination. Mills and Pettigrew found that waters containing calcium salts extracted a minimum of nitrogenous compounds from the barley; they also came to the conclusion that the esteem in which the Lichfield water is held for steeping purposes is due to the presence of nitrates which, they assert, have a stimulating effect on the subsequent germination of the grain. The writer has added lime-water to the extent of one-third of the total volume of water at the first change, believing it to promote regularity of germination. Bearing in mind, however, the observations of Adrian J. Brown, that the barleycorn is enclosed in a membrane permeable to water but impermeable to most salts, it is difficult to see how the saline constituents of water can have any effect except in removing matter from the external portions of the grain and on those corns which are broken. The apparent beneficial effect of lime-water in the steep is probably entirely due to the removal of matters from the husks or paleae. Malting floors may be constructed of cement, tiles or slate, the two former being preferable to the latter. Ford, in 1849, recommended 200 sq. ft. per quarter of barley steeped as the area of the working floors, and he was quite convinced of the necessity of allowing ample floor room, so that the grain could be worked on the slow, cool system. Subsequently, however, maltsters reduced their floor area, and put the grain rapidly through the malting, thus producing what is termed " forced " malt. This kind of malt was, however, condemned by practical brewers, and a chemical test whereby forcing could be detected having been devised by E. R. Moritz and G. H. Morris, maltsters have been compelled again to increase the area of their working floors. At the present time the approved area may be placed at 175-200 sq. ft. per quarter of barley steeped. The area is, however, largely ruled by the kind of barley to be malted. After the barley has been thrown out of the cistern it is made up in a rectangular heap 16-2o in. deep, called the " couch "; the object of this is to enable it to gather heat and so start germinating. It usually remains in couch for 12-24 hours, until in fact the interior portion of the heap registers a temperature of about 6o° F. During the days of the malt tax the exciseman gauged the quantity of the barley while it was in the couch. After couching the barley is spread thinly and evenly on the floor, forming what is known as the young floor or No. 1 piece. The first visible sign of germination is the sprouting of the rootlet, termed " chitting," and this occurs either while the grain is on the couch or on the young floor. As already mentioned, it may be quickened by aerating the grain in the cistern. From the time the barley is first cast out of the cistern up to the stage of the young floor, or No. r piece, it has a pleasant ethereal odour resembling apples. Drs Thomson, Hope and Coventry stated in the earlier part of the Igth century that they distilled " spirits " from germinating barley at this stage. In the light of our present knowledge it would not be surprising if alcoholic fermentation were proved to occur within the grain at this stage, since intramolecular or anaerobic respiration in certain vegetables has been found to be due to alcoholic fermentation. The thickness at which the young floor is spread depends upon the outside temperature and the nature of the barley. If the weather be warm, or if there be a tendency for the barley to heat, the piece must be spread all the thinner. At this stage the grain loses its external wet appearance. When spread too thickly pressed between the thumb-nails, but should crumble and disintegrate to a chalky mass having little or no adhesiveness. The foregoing observations are not to be regarded as hard and fast rules, but they are simply intended to give some indications of the malting process when it proceeds on normal lines; it may be that on account of the presence of damaged corns the piece begins to develop mould by about the tenth day, and it then has to be kept thin and sometimes even loaded on kiln prematurely. The malt made for grain distillers, in which a high diastatic activity is required, is manufactured on quite different lines from those above indicated. It is often sprinkled late, and loaded on kiln often in a sodden condition. In some cases sprinkling on kiln is resorted to, but it is doubtful if this the desired object. Other things being equal, the smaller the corns—i.e the greater number of embryos in a given weight—the higher the diastatic activity of the malt. In selecting a barley for the production of highly diastatic malt, the diastatic power of the original raw grain is a factor of great importance. Kilning.—When loaded on kiln, malt intended for brewing ale and stout is, if properly withered, in a moribund condition; nevertheless, during the first stages of the kilning process a certain amount of vital activity is manifested, and the malt undergoes mellowing by the action of enzymes on the contents of the endosperm. If the malt be loaded while the rootlets appear fresh on account of the presence of too much moisture, rapid growth of the acrospire ensues, giving rise to overshot corns, known in Germany as " hussars." To check this the moisture must be rapidly removed by the passage of large volumes of air through the malt. But under such circumstances mellowing does not occur. The ideal conditions of kilning are when the malt has been properly withered on the floors before loading, and, assuming that drying and curing occupy four days, that 25—30 % of the moisture be removed very gradually, this occupying the first three days, at the end of which the malt is said to be hand-dry. The thickness at which the malt is spread on the kiln should not exceed 7-8 in., and until hand-dry (that is to say, reduced to a moisture content of 12—15%) it should not be turned; if moved at all (and that only is necessary when reek occurs), it should only be lightly forked. The rate at which the temperature is raised depends largely on the kind of malt to be made and the construction of the kiln. If high flavour and colour are required, these are produced by keeping the malt for several hours near a temperature of x6o° F. while it still contains 12—15% of moisture. If more than this amount of moisture be present when the temperature reaches the limit just mentioned, the conditions known as stewing would obtain, with the result that " forced " malt would be produced. A certain amount of colour is produced at the final temperature to which the malt is raised; but when such means are relied upon for the production of the greater part of the colour, reduction of extract and deficiency of flavour follow, the colour being then almost exclusively the result of caramelization of the carbohydrates. The so-called curing stage constitutes the last part of the kilning process, and the malt must then be turned frequently to ensure uniformity of action. Mechanical turners are exceedingly useful for this purpose. Curing in a drum, as in the so-called pneumatic malting process (see below), also effects satisfactory curing. The following table will give an idea of the kilning temperatures usually employed for the three kinds of malt mentioned, but it must be remembered that these temperatures are largely regulated by the construction of the kiln and the amount of draught available. In this connexion it may be mentioned that the final curing temperature is not necessarily a criterion of the tint of the malt. A malt may have been finished off at a very high temperature and still be a pale malt, provided the moisture percentage has been sufficiently reduced in the initial stages of kilning. Running Pale Malt. Ale Malt. Amber Malt. 1st day temp. 90-100° F. 9o-too° F. 90-100° F.The average laboratory values obtained from malts of the descrip. tions after about two months' storage should be as follows: Running 2nd „ „ 100—120 I00—I20 I00—130 3rd „ „ 120-130(10 hrs.) 120—130(6 hrs.) 130-150( 6 hrs.) 3rd ,. „ 13o-18o( 8 130-150(12 „ ) 150-160(12 ,, ) 3rd „ , 18o-19o( 6 I o—180( 6 „ ) 16o-18o( 6 „ ) 5 4th ,, ,, drop to 170(12 ) 180—190(12 „ ) 18o—200(12 ) 4th ,, „ 190—200( 6 „ ) 200-220( 6 ,, ) 4th „ drop to 18o( 6 „ ) drop to 190( 6 „ ) Pale Malt. Ale Malt. Amber Malt. Extract per standard quarter of 336 lb 95-98 lb 94—96 lb 94-96 lb Moisture about 2.0 % in each case Diastatic activity (Lintner) . 30-35 20-30 8-10 Tint (Lovibond 52 series neutral) . 3-5 6-8 20—25 Metabolic Changes.—All through the malting process metabolic changes are proceeding, in which both carbohydrates and proteins are concerned. In its resting stage the embryo of a barley-corn is generally free from starch; as soon as germination sets in, however, starch appears in the scutellum, while the amount of sucrose there present increases, these being apparently formed from maltose originating from the action of diastase on the starch of the endosperm. Sucrose also augments in the aleurone layer, but starch is never formed in the aleurone cells. These changes occur when the malt is first loaded on kiln; indeed, at no part of the malting process is there greater physiological activity. Kilning has been specially studied by J. Gruss, who divides the process into four stages, the first being that at which the temperature limit is 113° F. It is characterized by a continuation of the living processes, especially growth of the acrospire, which, as already stated, proceeds too far if the malt be loaded too wet. In any case the rootlet dies away. The metabolism of the carbohydrates already mentioned is accompanied by that of the nitrogenous constituents, the reserve protein of the sub-aleurone layer being attacked by proteolytic enzymes and broken down into simpler compounds. This is a most important matter from the point of view of the brewing value of barley, for the degradation products of the proteins are necessary constituents of wort as yeast food. Moreover, unless proper modification of these protein bodies occurs it is impossible to produce tender malt. A barley which contains a high percentage of reserve protein is as a rule unfitted for malting purposes, and indeed, the higher the protein content the greater the difficulty the maltster experiences in dealing with it. Protein hydrolysis requires the presence of a certain amount of moisture, and if this be removed too rapidly by a forced draught at the early stages of kilning the proteolytic enzymes cannot perform their function. If, on the other hand, the grain be loaded in too moist a condition, and the temperature be raised too quickly, the proteolytic enzymes lose their activity and the proteins remain for the most part unattacked. When germination is allowed to proceed on the kiln too great degradation of the protein occurs, and the malt is liable to produce fretty beers, on account of the presence of an. excessive amount of nitrogenous nutritive matter, which leads to the development of disease organisms. The second stage of the kilning process, according to Gruss, is that at which the temperatures range from 113° to 167° F. The life of the corn is now suspended, but enzymatic processes continue. The starch is further saccharified, and the dividing line of the aleurone layer at the furrow is attacked, as are also the cell walls of the endosperm, which are still intact, these being partially converted into gummy substances. This change, however, also requires the presence of a certain amount of moisture. If too much air be passed through the malt at this stage the above-named dividing partition of the cell walls is not attacked. The air may expand the grain to some extent and produce malt of a low bushel weight, which, however, is not properly modified and cannot give satisfactory results in practice. During the third stage of kilning, an enzyme, which Grtiss claims to have recognized, and which he denotes spermoxidase, is said to exert its activity. Schonfeld has confirmed the discoveries of Gruss by practical experiments. Fuel.—The fuel used for drying and curing malt is either anthra, cite or coke, and the greatest care is necessary in selecting it on less extent an invariable constituent of all coal. The fuel used for malting purposes should not contain more arsenic than :nth grain per lb. Gas coke should on no account be used, unless it has been account of its liability to contain arsenic, which is to a greater or proved to be sufficiently free from arsenic; but the best oven coke frequently contains so little arsenic that it may be employed with perfect safety, especially if it be mixed with a proportion (e.g. 5 %) of milk of lime, which retains the arsenic as calcium arsenate. In Germany malt is, as a rule, dried and cured with hot air, whilst in Great Britain the products of combustion are passed through the malt, as it is believed that they exert a beneficial influence on the flavour. The proportion of fuel used for drying and curing malt varies according to the quality of the fuel and the construction of the kiln, but on an average it may be placed at 50-80 lb per quarter. Storing.—After the malt has passed through the curing stage it is generally heaped up for a few hours. This is believed to increase its flavour. The malt is then stripped from the kiln, and the rootlets, technically known as the coombs, are removed. Formerly this was effected by workmen treading the malt, who wore heavy boots for the purpose. At the present time, however, the rootlets are usually removed by machinery, special forms of which have been devisedthe green malt is loaded on an ordinary kiln and the initial stages of kilning (see above) conducted in the usual way; the curing, however, may be carried out successfully in a special form of drum. Yield and Weight.—The malting process is attended with a certain amount of loss of dry substance of the barley, as follows: In the steep 1.5 to 2.0% By respiration on floors and on kilns 3.0 „ 5.0 % Coombs 3 0 „ 4.0% Total 7.5 „ I 1.0% In addition to this, barley, as already mentioned, contains from 15 to 20 % of moisture, whereas finished malt contains i to 2 %. The total loss in weight which barley undergoes in the malting process may be put down at from 17 to 28%. Since, however, malt is lighter than barley (and the quantity of both was in former years [From Sykes & Ling, Principles and Practice of Brewing (1907), Charles Griffin & Co., Ltd.] for this as well as for dressing and polishing the malt. It is the custom of some maltsters to store malt with the rootlets still attached ; but this is an objectionable practice, since malt coombs attract moisture, and the presence of more than 3% of moisture in malt produces the condition known as " slackness." When the malt is packed in bin it is often covered with a layer of coombs, which then prevent access of atmospheric moisture. Malt, to preserve its good qualities intact, should be stored in bins made as nearly as possible air-tight, and it should never be placed in bin until it is quite cool. It is probably wrong to store malt in bins adjacent to the kilns, where it is kept at a higher temperature than that of the surrounding atmosphere. During storage of the malt a kind of mellowing occurs, the mechanism of which is not understood. It is, however, known by practical brewers that the best results cannot be obtained when new malt is used. Premature Malting.—Several years ago Galland suggested germinating barley in a drum, his idea being to do away with handling of the grain, and also to be independent of changes of atmospheric temperature. The latest development of this system, the so-called Galland-Henning process of pneumatic malting, has been improved by Mr R. Blair Robertson, and a diagrammatic view of the interior of one of these maltings, showing the drums and conical steeping cisterns, is shown in fig. 9. The drums are provided with a perforated channel for the passage of air through the malt, which is packed in the annular space between this channel and outside wall of the drum. Each drum is capable of revolving on its axis, and there are arrangements for passing either moist, saturated or dry air through the malt. The system as now improved is capable of producing some of the best malt, especially if, after germination has been completed in the drums,measured exclusively by volume), it frequently happens that a given number of quarters of barley yields a larger number of quarters of finished malt. When this happens it is usual to speak of an increase having been obtained. At the present time weight replaces measure for both barley and malt, and although it is usual to speak of the quantity of grain in terms of quarters, what is meant is not the measured quarter, but so many weighed standard quarters. The standard quarter for English malting barley is 448 lb and for malt 336 lb. From this it will be seen that when a given number of weighed quarters of barley yields the same number of quarters of finished malt, the actual yield is 75%, and there is then said to be neither increase nor decrease. As a rule, in practical working the yield of malt varies from a 4% decrease to a to % increase, corresponding to an actual yield on the original barley of 72 to 82.5 %. J. Baverstock, an old writer, says that finished malt should weigh one-fifth less than the barley from which it is produced. This corresponds to a malting increase of about 7%, which is a high yield. As a rule, foreign barley will give a greater malting increase than English barley, because, on the one hand, the former usually contains less moisture than the latter, and, further, because there is less loss on the floors by respiration and rootlet growth. The yield of malt from barley may be determined in the laboratory in an extremely simple manner. Since every grain of barley must yield a grain of malt, if we know the respective weights of a definite number of barley and malt grains, provided that this number is large enough to represent the average, then obviously this gives the data requisite for calculating the yield of malt from barley. The number of corns the weight of which is determined for this purpose is usually moo, and if the weight of this number be determined on several different i000 corns, the average will closely approximate to the truth. Instead of counting the corns by hand, an instrument may be used for this purpose. If i000 corns of a barley were found to weigh 42 grammes, and moo corns of a finished malt from the same bailey 32 grammes, then the yield of malt is 32 42 100= 76.1, this corresponding to a 1% increase. Assuming that the moisture content of the barley was 15% and that of the finished malt 2%, 100 grammes of malt will contain 2 grammes of moisture, and 76.1 grammes will contain 76.1 X 2 = 1.5 grammes moisture; therefore 76.1 grammes of malt Ioo contain 76.1 — 1.5 = 74.6 grammes of dry matter. This was obtained from ioo — 15 = 85 grammes of barley dry substance. Hence ioo parts of barley dry substance will yield 74.6 5 loo = 87.7 8 corresponding with a loss of dry substance equal to 12.5 % of the dry substance of the barley, or with a loss of 10.7% on the barley containing 15% of moisture. The results obtained by this method of laboratory control when it is accurately carried out agree very closely with those deduced from the practical results of weighing the barley, malt and coombs in the malting. Special Malts.—In addition to the kinds of malt considered in what precedes, there are others mostly used for imparting specific flavours and colour to beers and stout. These are crystal malt, imperial malt, brown or blown malt, and black or roasted malt. Crystal malt is grown for a shortened period on the floors, and then placed in a wire cylinder, which is rotated over a fire so that it is dried at a very high temperature. The weight per quarter is from 25o to 28o lb. Imperial malt is dried off on an ordinary kiln at a final temperature of 240—270° F., but it is not allowed the usual length of time on the withering floor. It is placed on the drying kiln in a layer not exceeding one inch and a half in thickness. A moderate heat from burnt wood is first applied until the bulk of the moisture has been driven off, when the temperature is suddenly raised so that the grains swell some 25% and the malt takes up a strong empyreumatic flavour from the products of combustion. This kind of malt weighs 270—300 lb per quarter. Black or roasted malt is pre-pared by roasting malt in a cylinder. Ford states that perfectly malted corn gives a colour of less intensity and permanence than does partially malted corn, and this has been confirmed by other observers. A certain quantity of the so-called black malt is actually made from raw barley, but this gives a product of inferior flavour. The weight per quarter of black malt varies as much as from 215 to 290 lb. Valuation.—For the valuation of malt the following determinations are usually carried out: Extract per standard quarter, moisture, diastatic activity by the Lintner process, tint, and matters soluble in cold water. The physical examination of malt is also a matter of importance, inasmuch as direct evidence is obtained thereby of the modification of the malt. Among the methods adopted for this purpose may be mentioned counting the percentage of corns in which the acrospire has grown up to one-half, two-thirds and three-fourths the entire length of the corn. In properly made malt the modification of the endosperm should proceed pars passu with the growth of the acrospire. The sinker test is also useful when carried out in an intelligent manner. Those corns which sink in water and lie flat are improperly modified. Normal malt has a specific gravity less than water and the corns have equal density throughout ; consequently they float horizontally in water. In forced samples the proximal ends are frequently lighter than the distal ends, and the corns float horizontally in water, with the germ directed upwards. The latter, however, may in some cases fill with water, and the corns lie flat or sink. This is a characteristic of over-modified malt. It will be seen from these remarks that it is essential to carry out the sinker test under standard conditions. The modification of the malt may also he determined by means of the diaphanoscope already referred to under Barley. A. R. Ling, Principles and Practice of Brewing (1907); H. Van Laer Bull. de la soc. chim. de Belgique (1905), 337 ; R. Wahl, Amer. Brewers' Rev. (1904), 18, 89. (A. R. L.*)
33 321 3111 222 221I 2IIII IIIIII

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