Lager Beer I


Mr. James G. Wells in the Chair.

The following paper was read and discussed:—

Lager Beer, Raw Materials, and Malting
by C. Rühl

I would explain that my paper deals with lager beer of the German type. Whereas top-fermentation was known at a very early date, bottom fermentation beer is of comparatively recent origin. It was first mentioned and authentically described by documents belonging to a Bavarian cloister, named Weihenstephan, where, towards the end of the fifteenth century, monks are said to have “produced” beer from barley, malt, and hops “only” and “the wort fermented by a special way of cold-fermentation and storage.”

But the general popularity and predominating importance of lager beer did not make its way until the second half of the eighteenth century, when from Bavaria and Bohemia this typical beer spread all over Germany and Austria, slowly but almost entirely superseding the common sorts of top-fermentation beers, and only leaving in existence a few special varieties produced in certain areas. However, top-fermentation beers were still leading up to and during the first half of the 19th century, and especially was it the English brewing industry which held the world’s fame and which was to strike the key note, so that brewers from all parts of the Continent went to England in order to study and practise English brewing methods.

From the total amount of all beers brewed in the year 1814 in the Kingdom of Saxony, 95 per cent, were still top-fermentation beers, whilst the statistics taken from the year 1900 show that all breweries belonging to North Germany produced altogether 37,300,000 hectolitres of lager beer, against but 7,412,000 hectolitres top-fermentation beer.

In Bavaria the production of top-fermentation beer amounted to only 1 per cent, of the total.

In 1907, statistics prove another remarkable decrease of top fermentation beer in favour of lager beer. The figures are as follows:—

Lager beers produced in North Germany, about 40,000,000 hectolitres, against but 5,867,000 hectolitres of top-fermentation beers. The whole of beer produced in all the German States together, in the year 1907, runs to 73,159,000 hectolitres.

The law prohibits the use of malt substitutes of any kind in Germany, and only malt, hops, water, and yeast are allowed to be used for the production of lager beer. So barley is “the only extract-yielding raw material” and of greatest importance. Therefore lager beer brewers are very careful in the selection of barley for brewing purposes. As far as Germany is concerned, 4- and 6-rowed barleys are generally not employed. Two species of summer barley are mainly preferred, and these are Hordeum distichum erectum and Hordeum distichum nutans.

The former group includes a few types not unknown in this country, viz.: Imperial, Juwel, or Goldthorpe, and Webb’s beardless barley. The latter group (nutans) is jointed in two sub-groups—Chevallier barleys and Land barleys. All these types, although differing in thickness or delicacy of skin, size and shape of the grains, and other physical characteristics, when grown in favourable soil possess all the characteristics required for the production of lager beer. One of the chief aims of the lager beer brewer is to procure barleys which are as rich as possible in starch, and this is the reason why summer barleys are preferred and bought, either by type or on guarantee not to contain more than a certain percentage of nitrogenous matter. With regard to buying barley on a guarantee of nitrogenous matters, my own experience has shown that barleys poor in nitrogen give higher extracts of a more desirable character, and cause less difficulties in malting, brewing, and during the whole of the process, than barleys rich in nitrogen. But barleys sold by this guarantee are certainly not cheap. The question is whether, when calculating the results, anticipations have been realised; and in this connection I may state that my experience has not always proved so. I have malted a great deal of barley, containing 15 per cent, and more of nitrogenous matters, and I may say that much can be done by suitable treatment in steeping, and during the whole of the malting as well, as in the brewing process. Within certain limits and for certain purposes—for instance, for the production of dark beers with much aroma and flavour—it may be advisable to buy cheaper barley, in spite of its higher content of nitrogenous matter, when this barley may yield, after being malted in a suitable way, a satisfactory beer meeting all the requirements. I shall later on have more to say on this point when dealing with malting and the different processes of brewing. For the present I need only remark with respect to barley of higher protein contents that, for the intelligent lager beer brewer there is a wide field for investigation, and I agree with Windisch that lager beer brewing will probably undergo a complete revolution in the near future. This revolution may extend to methods of malting. This is a subject of extraordinary importance, and I shall touch in detail upon it when speaking about the mash-filter.

Reverting to barleys and their valuation, I ought to say that there are generally two methods or systems in vogue by which brewing barley is valued, the Berlin and the Vienna systems. Both are well applicable and practical. Every practical brewer knows that external characteristics are sometimes very misleading, though, doubtless, some of them give very reliable information as to the suitability of the barley. Shape and fineness of the grain, the crinkles of the skin, soundness of smell and colour, supply indications which can never be ignored.

Another means of valuing barley is the hectolitre weight. There are some little apparatus acting very reliably, combining measurement and balance. Barleys having the hectolitre weight of 143—147 lb. are poor in starch and have thick husks; they do not pay to purchase even at a low price. Barleys having a hectolitre weight of 147—158 lb. are considered good and rich in starch, but it would be wrong to go to the extreme, and to assume that a barley having a high hectolitre weight must therefore be richest in starch, because there are some barleys poor in starch, rich in nitrogen, but nevertheless very heavy (lead barley).

The 1000 corn weight is also a valuable factor. Lager beer brewers do not regard barleys having the highest weight as the best, though barleys having large corns usually are rich in starch. The preference is given to corns of medium size. Most suitable for lager beer brewing are barleys having a 1000 corn weight of 38—44 grams, barleys having a 1000 corn weight of less than 35 grams are not fit for lager beer, whilst such in which the 1000 corn weight is as high; is 45—50 grams are considered as having too large corns, liable to cause disturbances, inasmuch as such large corns cannot be modified in the same time as smaller ones.

The Berlin system for the valuation of barley according to its percentage of nitrogenous matter is 7—10 per cent, for the choicest, 10—12 per cent, for choice to medium, and 12—15 per cent, for medium. Barleys containing more than 15 per cent of nitrogenous matters are refused as unsuitable for brewing purposes.

I am aware that there were many other points worth mentioning, as stack-sweating, kiln-sweating, storage germinating power, and so on, but I am compelled to pass on to another raw material, namely, hops. The first authentic report on culture of hops comes again from documents belonging to the cloister Weihenstephan, dated from the early years of the ninth century. I may state that hops were used long before this, but I have never heard from any authentic documents of an earlier date how they were cultivated.

It is the variety Humulus lupulus which is used for lager beer brewing.

The question which country or which hop-growing district on the Continent, under normal meteorological conditions, supplies the best qualities or highest grade is not easily described. Bohemia claims to produce the best; but there are certain districts in Bavaria which have long been famous for their high-grade hops, and, again, there are many Continental brewers and exports who have sworn fidelity to Wurtemberg hops, and prefer them above all. It would be waste of time to dwell on such-like opinions, because they are founded on personal experience, and every brewer draws his own conclusions from this. I would urge in this connection that it is quality which should be considered before everything else. But there are several wide-spread misapprehensions about hops regarding place-name as well as the quality, respectively valuation. One is that a considerable number of brewers base their judgment on colour, choosing very green hops, and thus running the risk of getting hops picked too early, and therefore not sufficiently ripe. This does not, of course, apply to the early sorts. The colour of good, sound, and well ripened hops should be a slightly yellowish green.

Hops, after being picked, must be dried most carefully in order not to spoil their most important ingredient, the lupulin. This is the constituent which in reality measures the value, which gives the correct standard of value, and for which the money should be paid.

The lupulin content should be as high as possible, and care should be taken that it is in the best condition. It should be of a light green yellow colour; dark yellow and brownish lupulin is either overdried or unsound. Hops may also be judged by their characteristic odour, and a connoisseur may from this, in conjunction with other factors, ascertain the district in which the hops have been grown. Size, appearance, and typical form of the cones are other factors characteristic of certain districts of fame. But I would point out that, although fame is generally well deserved, there are some factors of importance which no brewer should leave out of consideration.

The quality of a hop will vary according to the situation of the hop garden, the climatic conditions, and the nature of the soil. Hops grown in the same neighbourhood may exhibit differences. For instance, Bavaria is roughly divided into five chief hop-growing

districts, of which Hallertau is the most favoured, because the district produces on its large territory a very fine quality of hops, and there are practically no differences, or but very minute ones, with respect to quality all over the district. The same cannot be said, however, as regards the remaining four districts. Though each of them represents, so to speak, a certain hop variety, or better, a distinct commercial mark, the differences occurring within every single district are remarkable, and the varieties of hops grown in Bavaria number in reality up to more than twenty.

This is the state of things in Bavaria; and it follows, therefore, that the name alone is not always, and by all means, a criterion of value.

Coarse strigs and fruits are of very little or of no value, and hop types characterised by them are generally poor in lupulin, and should be refused. Some sulphur, when not applied in excess, does no harm, and serves well for keeping purposes. Lupulin is very unstable; this accounts for the fact that hops of the highest grade as well as others are liable to deterioration, especially when not suitably packed or stored. Dry, cool storage, at as constant a temperature as possible, is very essential. Hops of new crop are liable to self-heating, when not thoroughly dried and cured, and should therefore be carefully controlled for some time.

It happens more frequently than may generally be believed that the greater part of the lupulin is spoiled by unfit storage. This is bad, because the purposes for which hop is used cannot properly be served by spoiled substances.

The normal flavour and bouquet can only be attained when the essential oil, the bitter principle, the soft resins, the tannin—when, in fact, all the constituents of the hop are in a sound condition.

Bittering agents, as quassia, antiseptics, and preservatives, are prohibited by law.

Before dismissing the subject of hops, I wish to say a few words as to the size of hop-backs. I have seen hop-backs of very large dimensions, and in order to get a sufficient filter bed, a correspondingly large quantity of hops is necessary in such a case. This quantity, when consisting of high-grade hops only, will give too strong a flavour, and cost too much money, so an inferior quality of hops very often is used, not to the advantage of the resulting beer. Such beers must subsequently be flavoured in some way by appliance of high-grade hops. A hop-back of small size, fitted with mechanical sparger and press, allowing a quick and ready filtration, giving adequate filter bed area with a small proportion of hops, has proved a great benefit to many brewers. Such a hop-back has in practice not only saved much money, but it has greatly improved the quality of the beers. By its use the fermentations have been cleared, and many difficulties have been avoided, since they no longer have been compelled to use large quantities of inferior hops for the sake of filtration.

Malting.—The German law describes “malt” as cereal, artificially brought to germination. So, barley-malt is barley brought to germination. That sounds so plain, so simple, but, in reality, what sum of knowledge, ability, and experience is compressed into the simple little word malt. The late Professor Lintner used to term malt as “the soul of the beer,” and he justified this as follows:—

We take barley and make it grow—we are awakening its soul—we keep it alive and allow it to grow till the very moment when in nature it would be ready to make its appearance in springtime and sunshine; then we stop its growth by the process of kilning.

The barley, after being delivered to the malt house, is submitted to screening operations. The half-corns are removed, the barley is to be screened and sorted with regard to size of corns. Then the malting process, and I will only speak of floor-malting—starts, or better, the preliminary treatment begins, that is, washing and steeping. A good wash is very essential: it cleans the grains’ surface from dust, filth, soil, &c, as there are mould, bacteria, and other adhering parasites. This is done in connection with steeping and by manifold means or applications, frequently under assistance of lime water, occasional small quantities of sulphuric acid, or by means of air current, blown through with high pressure in the presence of water; thus, one corn cleansing the other by surface friction. The main purposes for which steeping is responsible are: providing the grain with the amount of water and oxygen necessary for germination, and extracting from the husks some undesirable substances.

The quantity of moisture and oxygen barley is allowed to take up in steeping stimulates and partly regulates respiration and growth. A barleycorn can absorb a quantity of water weighing more than half its own weight; but so much moisture is not requisite, and oversteeping, though it does not dissolve or extract anything from the interior of the corn, involves some disagreeable and objectionable consequences; it lowers the germinative capacity, and may give cause for rapid development of mould and bacteria.

German brewers name the absorption of moisture in steeping by degrees. They speak of high, medium, or low degree of steeping, and denote an absorption of:—

In order to obtain a uniform growth, barley should never be allowed to take up moisture to its full capacity; it is better to depend to some extent upon sprinkling on the floors. Apart from over-steeping the germinative energy increases in ratio with quantity of absorbed moisture; that is to say, that a barley of medium steeping degree is inclined to develop higher temperatures, to grow longer roots and acrospire, than a barley having a lower degree of steeping. The ratio for the absorption of moisture during the steeping process depends upon the condition of the steeping liquor, as well as on that of the barley.

The proportion of water absorbed in steeping is highest on the first day of steeping, very much lower the second, and lowest the last day. By application of cold water at about 60° F., the time required for the attainment of complete steeping varies from 60 to 90 hours, and in some cases it may differ more; but the absorption of steeping water can he accelerated considerably by the employment of temperatures from 100° to 120° F. We are indebted for this knowledge, as far as I know, to Professor Windisch, who first proved the applicability of hot water for steeping. I take the opportunity of mentioning at the same time another steeping process, which we also owe to Professor Windisch: the alternating air and water steeping. This process has, in Germany, and especially in North Germany, many advocates, and has come in vogue in very many leading makings. The process is based on the observation that the acrospire exhibits an eager desire for air. This was not taken into account in any former steeping processes, in which the steep was kept always under water and the latter was usually changed, perhaps twice daily. So the acrospire could not obtain the requisite quantity of air and consequently could not develop during steeping; frequently it was oven weakened in energy, and many maltsters of olden times will remember that they sometimes wondered for what reason a well-steeped barley lay for 24 hours on the floor and did not start sprouting. Here is the answer. Windisch recommends to steep the barley in hot water for some hours, change water and wash the steep, apply cold lime water and ordinary water in equal proportion, and let the steep remain in that solution for 2 to 3 hours. After this the steep is again changed, water being applied for a few hours and subsequently the grain left exposed a few hours without water. A sparger for filling is recommended. By this method the acrospire will get the requisite quantity of air, it can breathe and develop, and the barley will sprout, if not actually in the cistern, soon after being brought to the malting floor. Steeping as well as flooring can be shortened considerably by aid of the treatment above described, and the alternate air-water-steeping process is most favourably applied to barley which has been harvested during wet weather. Barley so steeped will require less work in flooring, because the growth is more uniform and develops less heat, consequently requires to be turned less frequently than usually; but it may happen that in a proportionally high percentage of corns the acrospire will grow to one-half of the length of a corn, whilst scarcely any root development has taken place—this does no harm, because all these corns will he found completely modified and in satisfactory condition at the end of the flooring process.

The flooring process has for its object the production of a well modified malt, with the minimum of waste. This result may be attained in different ways. As mentioned before, this germination is a kind of breathing of oxidation, and its intensity depends upon the applied proportion of moisture and air (or, better, oxygen). The respiration of the corn begins as soon as the acrospire starts growing, and internal modifications take place.

The starch of the corn is rendered partly soluble by the influence of enzymes, formed by the development of the acrospire and transformed into invert sugar, which is transported to the aleurone layer and back to the scutellum, where it, by reversion, is changed into cane sugar.

From there the cane sugar goes on to the acrospire, serving as food and building up new cells. Increasing temperature accelerates the acrospire’s growth, the formation of enzymes, and the hydrolysation of endosperm.

It is said that the starch cellulose is dissolved at the same time by the action of diastatic enzymes, probably cytase, and that inside the aleurone layer proteolytic enzymes are formed; the latter, analogous to the effect of diastatic power, hydrolysing the insoluble nitrogenous matters and degrading them to albumose, peptone, asparagin. All those processes are more or less effective, according to higher or lower temperature and to the proportion of moisture. By the process of respiration, oxygen is consumed, carbonic acid produced, and the temperature increased; these effects being decidedly apparent within a few hours after the steeped barley has been brought on the floor. The thermometer, placed in a bed, will slowly but continually show the mercury rising, the germinating grain will soon begin to sweat, and the quantity of carbonic acid will rapidly increase within the bed; if, then, the bed is not turned in tine time, the whole process will proceed with rapidity, too much diastase will be produced at the time, more sugar will be created than the acrospire is able to consume, because its respiration is cheeked by the presence of too much carbonic acid; by the influence of peptase, an excess of insoluble nitrogenous material will be rendered soluble, and the degradation of soluble nitrogenous matter will go so far that, instead of bodies similar to albumose, there will be produced substances similar to amides and peptones.

Modification, when carried to such a degree, entails a good deal of waste and is not therefore desirable, but the germinating beds have from time to time to be aerated, carbonic acid to be driven away, and temperature lowered down by way of turning the bed in the known mariner. The character of malt and the character of beer for which the malt is intended is the guiding factor as to the manner in which a germinating bed is to be led through flooring.

The task of the maltster who makes material for the lager beer brewer is not only the attainment of a uniform growth and sufficient modification with the least waste of time and valuable substance, the transformation of insoluble nitrogenous matter into soluble varieties, the secretion of diastase; his aim and care is just as much to provide for the requisite characteristics, according to the fact that he is preparing the only extract-yielding material for the beer. It is always advisable to conduct the germination, without forcing, on cool and uniform lines, so that the growth remains fresh till the end; thus the modification will be effected by a slower process, but more efficiently and thoroughly, up to the end of the corn; the loss of substance will be less, the degradation of albuminoids will go into the desired varieties, and the danger of attacks from mould will be diminished. The time required for flooring fluctuates between 7 and 8 days in Germany, depending upon the system which is in use; in Austria, 10—12 days.

Kilning.—This process has not only the purpose of bringing malt into keeping condition by depriving it of its moisture content, but, in addition to this, it is intended to supply certain peculiar malt characteristics. The process of kilning is divided into two operations:—

(1) In the process of preliminary drying; and
(2) In the process of finishing and curing.

In earlier times the former process was effected simply by exposing the green malt in very thin layers to draught and fresh air, whilst curing has been always brought about by means of kilning. Nowadays ordinary air drying is done away with and cleverly constructed buildings fitted with heating arrangements, air-mixing chambers, draught regulations—the latter separating one floor from the other by means of cold air—have taken its place. The number of constructions and different systems of kilns is remarkable. Some are especially constructed for the production of a certain type of malt only (Munich malt, Pilsen malt), others procure every type of malt required. I will keep clear of all special systems and only say that a good system of malt kiln is of greatest importance and very essential.

The modern malt kiln has to fulfil both duties, the preliminary drying and the finishing, and for these purposes two or three floors are provided. The upper floor is the preliminary drying floor, the lower the finishing floor. Most important is the function of the upper floor: it is the chamber where characters are produced—according to employment of heat in proportion to moisture content. When there is a good draught applied so that the malt dries quickly at low temperatures, then the diastase soon loses its influence upon starch and little or no invert sugar can be produced. The invert sugar present is turned by reversion into cane sugar or possibly into starch; a flour body is formed which, removed to the lower, floor with not more than 4—5 per cent, moisture, can be finished by application of comparatively high temperatures, say 130—190° F. Such malt will not get any torrefaction products, nor will it caramelise. The heat penetrates by the pores of the corn into the flour body, puffs up the latter and thus produces the “flour malt” above described.

Munich malt, on the contrary, has to remain as long as the time which is at disposal for the whole process will allow, on the upper floor with as much moisture as possible. This can be attained by partly closing the draught-canals, thus not allowing the air to pass through the upper floor-goods too quickly.

The proportions of air permitted to go through the upper floor are regulated by the moisture percentage which the malt must still contain when removed to the lower floor—and this is 18—20 per cent. Another way of attaining the same purpose is to load the upper floor by a larger quantity of green malt.

Large quantities of invert sugar will then be formed and this at suitable temperatures will partly be caramelised. Care must be taken that heat is not applied too early or too sudden, because vitreous malt would result.

This depends very much upon the condition of the kiln, and no fixed rule can be stated. As a rule, the temperature should never be raised over 110° F. as long as the kiln goods have 25 per cent, of moisture or more.

It must be understood that the lager beer brewer, in making “Munich malt” (a dark, highly flavoured malt), aims at a torrefaction, caused by steady heat and moisture, proceeding from the centre of the corn through the endosperm on to the periphery. He aims at saturating the malt with that peculiar aroma which is mainly due to the caramelisation of sugar, but, secondly, also to certain albuminoids which are destroyed by heat. Munich brewers, therefore, close all the draught-canals of their kilns for 4—8 hours, thus creating a steady heat inside the kiln goods on the lower floor—and not allowing the upper floor to lose too much moisture. The temperature depends, again, upon quality of barley and torrefaction power of the kiln at disposal; the latter is very fluctuating and it is essential that a new head maltster should first study his kiln apparatus entirely before fixing the details of the process and the finishing temperatures. The curing off temperature for “Munich malt” is 212° F. for a few hours.

The Chairman, in opening the discussion which followed, said they were fortunate in having been privileged to listen to Mr. Rühl, who was a practical German lager beer brewer. It was interesting to hear the experience of a man whose method of brewing was entirely different from that of the brewer of English beer. Whilst he was unable to endorse all Mr. Rühl had said from the scientific point of view, he (the speaker) did not purpose dealing with this aspect of the paper, but would make a few remarks more on the practical side of it. He gathered that barley growers selling to lager brewers gave a guarantee as to the nitrogen content of the barley, and the question that suggested itself was, what was considered a proper limit of the nitrogen content? Brewers in England were not accustomed to the idea of buying barley subject to a nitrogen limit; in fact, he did not think farmers would have time to get their barleys analysed before putting them on the market. He could quite understand that the nitrogen content—which seemed to be high—was not of so much importance in its bearing to lager beer as it was to English beers.

Many of the nitrogenous compounds which came from the malt were thrown out in the process of lager beer manufacture, i.e. in the long fermentation in cold storage. Mr. Rühl referred to the lead barleys as being very rich in nitrogen, and he would like to know where they were grown. Then Mr. Rühl laid emphasis on the weight test of barleys, and seemed to judge them more by the weight they yielded per certain bulk than by the quality. He (the speaker) thought they would hesitate to judge English barleys by that standard. Some of the lightest English barleys were amongst the best, and some of the heaviest types might at times be the very worst they could use. Mr. Rühl, as a German lager beer brewer, naturally praised highly the value of Continental hops, but, of course, had not had experience in brewing with English hops. He (the speaker) did not see that Continental hops were so much superior to those grown in England. The former certainly had qualities which were lacking in English hops; on the other hand, in his opinion, the Continental hops had some undesirable features, from which English hops were free. The green hop seemed to be characteristic of the Continental growth, but those present would agree with him that from an English brewer’s point of view, the green hop was not desirable. As to the bouquet in lager beers referred to by Mr. Rühl, he would like to know how he considered this was obtained? One would have supposed that the cold fermentation process would practically precipitate all aroma-giving bodies—then where did the aroma, or bouquet, come from? When Mr. Rühl spoke about the steeping of barley and referred to the various materials used in the steeping water, he thought he should have said “sulphurous acid” instead of a “sulphuric acid.” The question of steeping was one of much importance, as was also that of the amount of moisture remaining in the barley at the end of the steeping process. That again involved laboratory investigations which he did not think that ordinary commercial processes allowed of. He thought that the English system of so many hours’ steeping was to be preferred; in fact, he felt he would experience difficulty in arranging a steep to leave at the end a specified percentage of moisture. As to the temperature of the steeping water, he was surprised to hear this was so high as 104-° or 106° F. Mr. Rühl had spoken of the aeration of the steep, and this was recognised in England as being advantageous to the germination of barleys. He was also surprised to hear that the flooring of the malt in Germany was limited to seven or eight days, but perhaps this was explained by the fact that the steeping was carried on for part of the time at a temperature of 104° or 106° F. In England, a flooring of only seven or eight days would mean they would get steely ends and flinty corns, which would certainly not be to the advantage of the brewer.

Mr. Rühl reminded the gathering that his paper had exclusive reference to lager beer brewing. As to lead barley, he said there were some districts in Bulgaria which produced barleys very rich in nitrogenous matter. These barleys were very heavy, and were not suitable for lager beer brewing. The bouquet in lager beer was imparted by the hops. The hops were not all used at the beginning of the brewing process, but usually they were employed in portions, the finest grade of hop being added a few minutes before the process was finished, with the object of giving a bouquet to the beer. This bouquet was made permanent by means of cold storage, for the reason that the oils in the hops kept better at a low than at a high temperature. Mr. Wells was in error in suggesting that the acid used in steeping was “sulphurous” and not “sulphuric.” Sulphuric acid was used in cases where the barley had suffered by rain. A small quantity of this acid removed any smell there might be in barley affected by rain.

Mr. C. F. Hyde inquired what percentage of sulphuric acid was used.

Mr. Rühl replied that only very small quantities were used. The first steeping water might contain a few cubic centimetres of sulphuric acid. He referred to Professor Brown’s observations that sulphuric acid was not absorbed by barley. Adverting to steeping temperatures, Mr. Rühl remarked that if they took a small proportion of barley and steeped it in hot water of 100—120° P. for a few hours, then washed it and put it into the germinating apparatus, they would find that it would not grow a bit quicker; in fact, he should say that in this case the barley would grow slower than ordinarily steeped barley. Some lager brewers steeped a small proportion of barley for four, five or six hours in hot water.

The Chairman inquired if it grew any better.

Mr. Rühl replied that it grew more regularly. Practical experience had proved these facts.

Mr. F. G. Richards asked whether in those cases when the first steep contained sulphuric acid it was the practice to follow with steeping liquor containing lime water.

Mr. Rühl, in reply, said he could not say. He first heard of the use of sulphuric acid in steeping about two years ago when a friend, who produced malt for sale, told him that a barley with a bad smell might mean a loss to him. This led him to make experiments, and he found that sulphuric acid removed the smell. Replying to another question by Mr. Richards, Mr. Rühl expressed regret, that, as he was not a chemist, he was unable to place before them the value of hops from the point of view of tannin. His experience was only that of a practical brewer, but he was aware of Mr. Chapman’s work, and he mentioned hop tannin, because he had heard that every high grade hop contained a proportionally high percentage of hop tannin and, if that proved true, it might furnish an easy criterion for the valuation of hops.

Mr. Hyde said that he understood that in North Germany they used raw grain to some extent.

Mr. Rühl said the North Gorman brewers a few years ago agitated and got passed a law prohibiting the use of substitutes. Up to a few years ago the brewers in North Germany had been free to use sugar and raw materials, such as barley or rice or other ingredients, so long as they were of good quality. The competition of Bavarian beers however (which were only allowed to be made from malt and hops), led to the North German brewers getting a law passed prohibiting the use of substitutes, so that in North and South Germany the brewers were now under the same law, and could not use anything in the production of lager beer but malt, hops, yeast, and water.

Mr. C. F. Hyde pointed out that in the January Number of the Brewers’ Journal, p. 43, under “Continental Brewing Notes: Rootless Malt,” the authors steeped for 20 hours at 130° F.; barley that was then floored at 57o F. for three days turned lightly and then cured slowly and lightly, no spire or root being developed. He asked Mr. Rühl if this treatment was not closely related to the first mash of Bavarian brewers, wherein the proteolytic enzymes’ action plays an important part in the modification of the insoluble albuminoids.

Mr. Rühl replied that he understood that proteolytic enzymes acted both in the malting and brewing processes.

Mr. A. H. Morris, alluding to the nitrogen content of barley, said a brewer buying barley in small lots, as was the usual custom in England, could not wait for the results of analysis for nitrogen content, and he would ask, therefore, if in Germany barley was bought in large lots, in which case it might be possible to wait for the result of analysis.

Mr. Rühl answered that in Germany the small dealer, selling a few hundredweights of barley of his own production, would know nothing about nitrogenous matter, and would not give any guarantee as to nitrogen content. This was only done in cases where barley was bought in large quantities. In Germany there were certain districts where barley was largely grown, and the merchants sold in large lots. If he bought from those merchants he would receive a guarantee that the barley contained between 10 and 12 or 13—15 per cent, of nitrogenous matter. Small dealers, however, gave no such guarantee.

Mr. E. Boulton asked if the hop-press, of which a sketch had been shown, was used before or after the boiling of the wort.

Mr. Rühl said that it was used when the process was finished—when the beer left the hop copper.

Mr. Morris said that he had heard of “Chit” malt being used in Germany, and ho would like to know with what benefit, if any.

Mr. Rühl answered that he had intended to speak about “Chit” malt, but found that if he introduced this subject his paper would have been too long. He, however, promised to deal with it before commencing the second part of the paper.

Mr. Morris inquired what benefit was supposed to be derived from “Chit “malt.

Mr. Rühl said the benefit was a higher extract, but they could not get more extract with their present brewery plants. This was one of the things for the future consideration of the brewhouse. “Chit” malt could not at present be worked by itself. It required a certain quantity of ordinary malt to obtain the necessary amount of diastase. Only where fine flour mills were available could there be extracted 1 per cent, or a slightly greater extract; but where the malt could be ground very fine, and by means of the filter press, it was absolutely certain they would get more extract than had been obtained in the laboratory.

Mr. A. E. Taylor asked the author if he favoured the filtration of the mash through the filter press just as he favoured the filtration of the wort through the hop-press shown.

Mr. Rühl said what he had stated about the filter presses was not based upon his own experience. Although he had not worked such a press, he had seen them in use and noticed how they had been gradually improved.

Dr. A. K. Miller, in moving a hearty vote of thanks to Mr. Rühl, said the practical nature of the discussion proved how really his paper had been appreciated. In his opening remarks the Chairman pointed out that Mr. Rühl came before them, not as a chemist but as a practical brewer. At the same time, they must admit that he had shown a considerable amount of scientific knowledge of the subject he had dealt with. He had the privilege of reading the paper before the Meeting, and had asked Mr. Rühl the same question as Mr. Wells with reference to the use of sulphuric acid in the steep. Mr. Rühl, however, maintained that he did not mean sulphurous acid, and he (Dr. Miller) saw no reason for doubting the use of sulphuric acid in the steep water. Mr. Rühl had referred to Professor Brown, who had shown that sulphuric acid did not penetrate to the interior of the corn and did not interfere with its subsequent growth.

Mr. Boulton seconded the motion, and, referring to cold storage, asked if, in Germany, cold storage of hops was adopted in lager beer brewing.

Mr. Rühl said that it was, but opinions differed about it. Some brewers favoured it, and others declared they could not find much good in it.

The resolution was then carried unanimously.

%d bloggers like this: