A Practical Treatise on Brewing

Front matter

A

PRACTICAL TREATISE

ON

Introduction

A

PRACTICAL TREATISE

ON

BREWING.

INTRODUCTION.

So many treatises on Brewing, both theoretical and practical, have already appeared, that the subject may very naturally be considered to have been exhausted. Some of these productions, however, are too homely; while others so abound with scientific technicalities, as to be altogether unintelligible to the general reader.

That Brewing is a chemical process, no one can deny, and of course, in every work on the subject, some chemical terms must be used. In the following pages, however, it is not intended to give any account of the production or nature of gases or other chemical agents, further than may be absolutely requisite to elucidate the subject. Nor is it intended to introduce a history of the origin of Beer, which must in a great measure be conjectural.

In most arts, such as dyeing, iron-making, calico-printing, glass-making, &c., great improvements have been introduced by the assistance of che

while the art of Brewing, which may be

considered equally important, has remained, to say the least, stationary. This may be easily accounted for. It is well known that many eminent chemists have turned their attention to this subject, and would no doubt have made as great improvements in it, as they have done in other arts, had they been furnished with the same advantages in regard to practical information. This, however, unfortunately has not been the case; for practical brewers, generally speaking, either from self-sufficiency, jealousy, or ignorance, are very unwilling to impart their real or supposed information to any one; but particularly to men of science, whose inquiries excite their jealousy. This in many instances, prompts them rather to mislead than to inform the inquirers.

Another obstacle to improvement is, that almost every brewer in the course of his practice, persuades himself that he has made some discovery, by which he can make his beer better than that of his neighbour. These nostrums, though often worse than useless to the possessors, might, if freely communicated to scientific inquirers, lead to some improvement; but they are invariably concealed, and thus the want of the combination of science with practice, throws insurmountable difficulties in the way of acquiring useful and accurate information. Had it been otherwise, there can be no doubt, that the Art of Brewing would have been long ago placed, by the assistance of chemistry, on a more scientific footing.

Having had occasion, in the course of a connection of more than forty years with the brewery, to work in premises very differently constructed, we have invariably found, that in each some cause existed which prevented uniformity in the process of fermentation; and until that cause, whatever it might be, was traced and removed, no regular system could be introduced. This sufficiently shows why brewers who go from one brewery to another, cannot arrive at the same successful results with regard to the quality of the beer, although they pursue precisely the same system, and even on some occasions employ the same materials as before. They are thus, from want of chemical knowledge, left completely in the dark, without the possibility of tracing causes and effects. This shows the absolute necessity of applying the discoveries of chemistry, as in other arts, to account for and rectify these anomalies, which without such aid cannot be effected.

The principal object of the following treatise is to trace the causes of these anomalies, and as far as possible to point out the means of removing or rectifying them; and on all occasions to advance only such opinions as are founded on principles strictly chemical and practical, without which, in the present improved mode of research, they can be but of little value; dogmas being now entirely exploded.

Many brewers are highly indignant when supposed not to be thoroughly acquainted with the art of brewing, in every department. We generally find, however, that they who exhibit the greatest self-conceit, are the most ignorant; trusting every thing to chance, and professedly paying no regard either to aromas or appearances of any kind. Strange to say, however, in some instances, such brewers succeed better than those who follow a more scientific system. This may be accounted for on principles which have no reference to any scientific knowledge of brewing. It is possible that their brew-houses may have been, by mere chance, so constructed, as to render their operations less liable to the electro-chemical fluctuations which are constantly going on in the earth and atmosphere, or which are caused by an injudicious mixture of metals connected with their gyle tuns or other utensils. When, however, the said brew-houses must be altered or enlarged as circumstances may require, how often do we find that the chance turns against them, and that by the introduction of different metals, in what is called the new and improved mode of constructing utensils, or from other causes, the quality of their beer is so much deteriorated as materially to injure the trade. It is then only that the self-sufficient brewer begins to discover, that his knowledge of brewing is only superficial, and his process dependent upon fortuitous circumstances, which nothing but a distinct knowledge of chemistry can enable him to comprehend.

It will, therefore, clearly appear, that when alterations are required in an old brew-house, or a new one has to be constructed, the greatest care must be taken to avoid, as far as possible, in the formation of the utensils all electro-chemical agency.

Should the following work be the means of drawing the attention of brewers in general, not only to the injurious effects of electro-chemical action, but also to other causes which prevent successful fermentations, and thus introduce a more scientific and a more uniformly certain system of brewing than has been hitherto established, the Author’s object will be accomplished.

It is impossible to describe in writing the different aromas and appearances, so as to make them intelligible, according to our own sentiments on the subject. We have, however, endeavoured to give as much information as possible, in plain, simple language, so as to suit every capacity: but it is only as they may occur in practice, that the different appearances and aromas, indicative of good or bad fermentations, can be described and pointed out; and no one should pretend to possess a thorough knowledge of brewing, until he can at once discover and rectify every thing which happens unfavourable to the desired result,—the production of good, sound, malt liquor.

Brewing

BREWING.

Before commencing the subject of brewing, it may be proper to say something of the nature of the ingredients used in the manufacture of beer. We shall, therefore, begin with water, the most indispensable ingredient.

Water

WATER.

The word Liquor is technically applied in the brewery to water. A great deal more importance is attached to the quality of this indispensable article than perhaps it deserves. Many are of opinion that the difference in the flavour and quality of beer proceeds in some measure from the different substances contained in the water used by the brewer. To this opinion we cannot subscribe, for it is im possible to suppose that any slight difference discoverable by analysis, in the quantities of carbonates or sulphates which may be dissolved in the water, could possibly affect either the flavour or quality of the beer.

Water, as usually met with, contains the following substances, which may, chemically speaking, be called impurities; namely,

Carbonic acid gas, to which the sparkling appearance of pump or spring water is owing.

Carbonate of lime, which is nearly insoluble in water, but which is often held in solution by excess of carbonic acid. When such water is boiled, the carbonic acid in excess is expelled, and the lime falls down, forming the crust in boilers and other similar vessels.

Sulphate of lime: this salt communicates the “hard” property, as it is called, to water, and is always known to be present, when soap which is dissolved in it curdles.

Besides these impurities, water always contains muriate of soda (common salt), and often other muriates. By using the term impurities, we do not intend to imply that anything exists in the Water, which, when it is drunk, renders it prejudicial: the term simply signifies any substance foreign to the real composition of water. Even rain-water, which is the result of a natural distillation, contains impurities.

Of mineral waters we shall say nothing, as no one could think of employing them in brewing, unless from necessity.

The above mentioned saline substances, we believe, cannot impart any flavour either to the worts or the beer. Carbonate of lime, as above mentioned, is partially separated by boiling, and sulphate of lime may be easily decomposed and the lime separated by a little alkali; as, for instance, by carbonate of soda. We thus reduce the different kinds of water to the same condition, and the products will also be the same.

While brewers and others are continually speaking of the water with which they brew being preferable to any other water, they never think of the difference of the soils on which the barley is grown. Now as the wine from grapes raised on one soil is inferior to wine from grapes produced on another, so every farmer, from experience, will tell you, that such and such soil is not fit for barley; and there can be no doubt that barley grown on certain soils will make inferior malt. In such cases the water used in brewing is often blamed, while the inferior malt, which is the real cause, is blameless.

Stagnant Water.

Many brewers suppose that, by exposing water to the action of the atmosphere for a certain period, they soften it, and make it more fit for the purposes of brewing, and others even prefer stagnant water, even when they have an abundant supply of fine pump-water at command. Exposing spring-water to the atmosphere can do very little harm in winter, and perhaps as little good; but in summer it soon becomes, by exposure, impregnated with filth like stagnant water. Would any one, we ask, after having seen a drop of stagnant water, as exhibited by the oxy-hydrogen microscope, think of using it for brewing, unless from necessity? Yet we have seen people, who were so prejudiced in favour of old customs, as to persist in using it even at considerable expense, and after its baneful effects had been distinctly pointed out, at the same time that they had an abundant supply of fine spring-water always at command, which cost them nothing. There can be no doubt that putrefactive fermentation must at all times, during summer, be going on in all stagnant waters, produced by the falling of leaves, and the depositions of innumerable insects.

This water, we all know, cannot be drunk without prejudice to health; and it is also very unfit for culinary purposes. How then can it be fit for brewing?

In some parts of the kingdom, however, no other water can be procured, and we have seen it impart putrescence to the beer, which could be discovered when smelling or tasting it. In all such cases, the water should be boiled, and allowed to cool naturally before mashing; or still better, a quantity of charcoal and lime should be boiled in it, which will, in some measure, correct the putridity. Would the action of chloride of lime be advantageous in such cases?

Running Water.

Running water from rivers or rivulets, although preferable to stagnant water, is still open to some of the same objections, being liable to contain some organic matter. In the first place, We do not know how many different mineral springs may be discharged into it; and in the next place, it is, in summer, liable to be contaminated with the same impurities as stagnant water, although perhaps not to so great an extent.

We shall sum up the Whole that may be advanced on this subject, by recommending the purest water which can be found, as fittest for brewing; and by stating that spring-water (not mineral) when immediately pumped up, has the best chance of being pure.

Barley

BARLEY.

Any kind of grain can be converted into malt: but in England it is most usual to employ barley for that purpose. There are three species of barley.

1. Hordeum Distichon, the common barley, characterised by two lateral rows of seeds on the spike. Professor Thomson’s experiments give 0.343 inch as the average length of a seed; 0.143 the breadth; and 0.108 the thickness.

2. Hordeum Vulgare, commonly termed Bigg in Scotland, having, according to Linnæus, two rows of seeds more distinct, and two imperfect ones.

3. Hordeum Hexastichon, with hermaphrodite flowers and six rows of seeds.—Records of General Science, vol. i. 441.

By the experiments of Professor Thomson in 1806, malt of bigg of that year was found inferior to that of English barley by 14 per cent.: the weight of the bigg being 48.848 lbs. per imperial bushel, while the barley weighed 51.444 lbs. From these experiments the excise duty on malted bigg was fixed at 16s. per quarter, whilst that on malted barley was 20s. 8d. per quarter.

Since 1806, from superior knowledge of agriculture, and the selection of improved varieties of the different grains, &c., both barley and bigg have much improved in quality, and have increased in weight per bushel: and it is now the opinion of some practical men, that the best bigg is very little inferior to barley for malting.

In malting barley, the loss in weight is from 21 to 22 per cent. Of this 14 consists of moisture, 1½ disappears during the steeping, 3 on the floors, 3 by commings or rootlets, and the waste 1½. As barley when thoroughly dried loses 6 per cent. of moisture, Professor Thomson considers the actual loss in malting as only 8 per cent.

The specific gravity of barley is from 1.280 to 1.333, that of malt 1.201.

From the interesting experiments of Messrs. Colin and Edwards upon the germination of different kinds of grain, it appears that when wheat, barley, French beans, or linseed, were immersed for a quarter of an hour in water at the temperature of 154° F., the power of germination was completely destroyed; and that water at 122° F. is the highest limit at which it is possible for barley to germinate after immersion.

It is very beneficial to kiln-dry the barley before malting. In the early part of the malting season, when the barley is damp, it cannot be made into good malt, unless thoroughly dried on the kiln. The grain absorbs moisture with greater avidity and regularity, and the process is facilitated. In good seasons, when barley is abundant, of good quality, and of a low price, brewers would find it very advantageous to lay in and kiln-dry a large stock, to be kept for malting the next season. By kiln-drying it will be kept perfectly sound, and will malt as freely or more so than new barley; and should the season prove unfavourable, such provision will be a considerable saving.

By the same valuable experiments of Messrs. Colin and Edwards upon the germination of different kinds of grain, we are led to suggest that the temperature used for drying the barley should not exceed 122° F., while in drying pale malt, the temperature is frequently as high as 160° or 170°. In the Records of General Science, vol. i. 445, Dr. Thomson states that very pale malt may be dried, although the temperature be brought as high as 175°.

The medium, however, through which the heat is communicated, modifies the range of temperature considerably. Thus the seeds before mentioned, if exposed to a temperature of 143° in air containing vapour, or of 167° in dry air, are deprived of their vegetating properties; and when wheat, oats, or barley, had been kept in sand at 113°, they would not germinate. Immersion in water at 167° for 14 seconds destroyed the power of germination. The grains of starch burst at a temperature of 167° according to Raspail.

In the Ann. de Chimie et de Phys. tom. v., Ann. Philos. xii. p. 201., Proust gives the following comparative analysis of barley and malt:

| | BARLEY. | MALT.

Resin | . . . . . . . . . . . . | 1 | 1

Gum | . . . . . . . . . . . . | 4 | 15

Sugar | . . . . . . . . . . . . | 5 | 15

Gluten | . . . . . . . . . . . . | 3 | 1

Starch | . . . . . . . . . . . . | 32 | 56

Hordein | . . . . . . . . . . . . | 55 | 12

100 | 100

These component parts, however, must differ considerably according to the different qualities of the barley from which the malt is made. Dr. Turner says, “the conditions necessary to vegetation are three-fold; namely, moisture, a certain temperature, and the presence of oxygen gas.” The necessity of moisture to this process has been proved by extensive observation. It is well known that the concurrence of other conditions cannot enable seeds to germinate, provided they are kept dry. That the presence of air is necessary to germination was demonstrated by several philosophers, such as Ray, Boyle, Boerhaave, and Muschenbroeck, before the chemical nature of the atmosphere was discovered. Achard afterwards demonstrated that seeds in general would not germinate without the presence of oxygen gas; and his experiments have been fully confirmed by subsequent observers. It has even been shewn by Humboldt, that a dilute solution of chlorine, owing to the tendency of that gas to decompose water and set oxygen at liberty, promotes the germination of seeds.

The late experiments of Saussure (1834) prove that in germination nitrogen is always absorbed.

The best barleys for malting are those called mellow in contradistinction to those which are hard or steely. The mellow barleys, generally speaking, are thin-skinned, and when the pickle is divided, either by the teeth or a pen-knife, the kernel is white and floury. The steely barley may also be thin-skinned, but when divided in the same way, the kernel has a bluish cast something like rice. This barley, although equally heavy, or even heavier than the other, will never produce such good malt, nor will the beer brewed from it have the same mellowness or richness of flavour as that produced from mellow malt.

Care should also be taken, that corn of different weights and from different soils, should be kept separate, so as that each different quality may be used alone. The heavier barley will generally require to be longer under water than the other, and when mixed will not grow equally on the floors, (an objection usually attending shipped or foreign barley), thus preventing the possibility of making fine malt. It will also be found, that cargoes of barley will never make such fine malt as that bought directly from the farmers. The reason is obvious—the different qualities cannot be kept separate.

Malting

MALTING.

Many opinions are entertained as to the best mode of making malt; some persons being great advocates for sprinkling the corn with water during certain stages of the process upon the floors, while others maintain that nothing of the kind is necessary, but rather injurious. As this is not intended for a treatise on malting, we shall not enter into any discussion upon that subject; but shall merely observe, that the practice may be either necessary or not, according to circumstances. In some malt-houses we have found it absolutely necessary to sprinkle for promoting vegetation, while in others, differently constructed, nothing of the kind was required.

The Excise allows sufficient latitude for wetting any kind of barley; it must not, however, be less than forty hours under water. The general mode of ascertaining when barley has been sufficiently steeped for malting, is first by its increase in bulk as shown by the dipping rod. A practical maltster generally judges from the compressibility of the pickle when squeezed endways between the thumb and finger. When sufficiently steeped, and after the water has been discharged, the barley is thrown (or in some instances drops through a valve or socket) from the cistern into the couch, where it must by law be let remain undisturbed not less than twenty-six hours, but longer if thought necessary. It is then spread out upon the floor to a thickness greater or less, according to the season and temperature of the atmosphere, at the discretion of the maltster. The rootlets now begin to make their appearance, and great care must be taken to turn the corn occasionally, but gently, so as to prevent any of the fibres shooting out too long, or wiry, as it is technically called. A short bushy root is most desirable. But each variety of barley exhibits different lengths of rootlets. Thus the chevalier is very different from the common barley and the bigg.

No definite rules can be laid down as to how often the floor or piece of malt may require to be turned during the process; this must be left to the skill and judgment of the operator.

Although the law does not permit water to be sprinkled on the corn until after a certain period, when in our opinion it should be no longer necessary, yet the maltster is allowed to sprinkle water upon the bare floor before turning the corn either forward or backward, and this may often be found very beneficial.

Some maltsters have now adopted the thermometer as a sure guide during the process: whenever that instrument indicates an increase of temperature of so many degrees, the malt is turned. This, however, is not a certain criterion. The thermometer will be found a highly useful instrument to guide an inexperienced operator to a certain extent, but it should be used in conjunction with practical skill, else it may do as much harm as good. The humidity of the atmosphere over the malt should be taken into account. The thermometer only shows the temperature, a hygrometer (Daniel’s) would point out the moisture, &c. Quite as much injury is done by turning too often, as by repeating that operation too seldom. An experienced maltster is guided a great deal by the appearance and smell of the corn in process, and also by the increase of temperature. The common mode of judging is by thrusting the hand into any piece of malt, and taking from the bottom a sample. The state of the rootlets of this portion are then examined; if they are running wild, as it is technically termed, or one fibre be protruding far beyond the others—the corn should be turned—if any fœtid smell be perceptible, the same operation is necessary, and also a fresh current of atmospheric air to supply more nitrogen and oxygen to the malt. Mr. Rigg’s late publication states that a great deal of carbon must be given out during the germination of the malt. It has been already stated that short bushy rootlets are the best; the great desideratum, therefore, is to preserve these bushy rootlets, which can only be accomplished by proper care and judgment in turning the corn. The skill of the maltster may be always known by this criterion. Whenever the rootlets begin to appear the spire or acrospire begins to shoot up at the back of the pickle, and as it proceeds the barley is converted into malt. The nearer, therefore, that the spire can be brought to the far end of the pickle, without protruding beyond it, the more perfect will be the malt. About the fourteenth day, generally speaking, the malt should be ready to be brought to the kiln—previously, however, it should be gradually made mellow, by gathering it thicker on the floors, so as to come to a temperature of 75° or 80° F. The steep or any water which may have been applied during the process, should have been by this time pretty nearly evaporated, so that the malt may feel dry to the hand.

Drying Malt.

There are various opinions as to the best mode of drying malt, some adopting a long process, and others a process much shorter. If the kilns are properly constructed, and the malt be thoroughly made before being put upon the kiln, twenty-four hours, or perhaps less, will be found fully adequate for that purpose. The greater the quantity of heated air that can be thrown in during the process of drying, the more mellow will the malt be. The best constructed kilns, therefore, are those by which the greatest quantity of heated air can be most quickly introduced. If a great current of heated air be constantly directed through the malt on the kiln no danger of acquiring colour need be apprehended. This current of heated air, however, should be admitted through open apertures, running longitudinally along the furnace fire, on the outside of the Welch lumps of fire-bricks. If, on the contrary, colour should be wanted, it is only necessary, just before taking the malt off the kiln, that all currents of air should be shut off or prevented, excepting from below the bottom of the furnace; a quick fire having been previously made and kept up, any colour may be very speedily acquired. Care, however, must be taken, during this process, by frequently turning on the kiln, to prevent the malt being burnt.

There is a prevailing error, that malt should be frequently turned on the kiln during the process of drying. A little consideration, however, will show the inaccuracy of this opinion. It has been already stated, that when the proper currents of heated air are introduced in drying, no colouring of the malt need be apprehended. We know that the portion of the malt nearest the covering of the kiln sometimes feels quite dry, while that on the top is quite damp; if, therefore, by turning, we throw this part of the malt upon the top and the wet to the bottom, the steam of the wet malt from below must pass through the drier malt on the top, thus creating double work. The steam, also, by again passing through the drier malt on the top, tends to render it tough. If the kilns be properly constructed, turning is not only unnecessary, but injurious, until the malt be nearly ready for removal from the kiln, when several turns, with a brisk fire, may be necessary to render the dryness of the malt uniform; by which, also, the malt will be rendered uniformly mellow.

This, perhaps, may be thought merely theoretical; but the author’s own practice as a maltster, and also that of several experienced maltsters, to whom it has been communicated, and by them adopted, will prove the contrary.

Malt

Selecting Malt for Brewing.

It is of material consequence to the brewer to have the best malts for the purpose of brewing. Some brewers, when working with inferior malt, think that an additional quantity will compensate for quality. This is, however, an erroneous opinion. Inferior malts can never impart the same mellowness and richness to ale or beer as those of superior quality. From using inferior malt, we also run a risk of having unsound worts. The best, therefore, will be found the cheapest.

Shipped Malts.

Shipped malts, as they are generally termed, are those which have been manufactured in various parts of the country, and from thence sent by sea to London.

Such malts have not, in general, been thought so good, nor have they brought so high a price, in this market as those made at Ware, or in other districts nearer town. The beer when brewed from them was not considered so good, nor thought to keep so well, as that from malts made nearer home, and the country maltsters were not considered to be so well acquainted with their business, and, consequently, their malt did not bring so good a price as that of the others. We are, however, inclined to think that the bad repute into which their malt had fallen did not proceed from any want of skill or care in the country maltsters, or even from any inferiority in the article itself, but from their having adopted an erroneous mode of treating it, immediately after it had been taken off the kiln. They had an idea that by sprinkling it with a little water when it was quite hot, it was rendered mellow, and that this being done before the malt was shipped, caused it to stand out to its measure upon its arrival at its destination, without otherwise in any way injuring it.

Wetting the malt in this way, would not only make it stand out to its measure, but perhaps even produce a little increase in bulk, which was no doubt a great desideratum.

When the malt was used immediately, this treatment might possibly do no harm, further than occasioning some little decrease in the quantity of the extract, the wetting having caused a trifling increase in its bulk, without improving its quality. When, however, the malt so wetted before shipping, was kept for any length of time, it became slack, and the beer brewed with it, as will invariably happen under such circumstances, did not keep, and soon became acid or stale.

This, therefore, was without doubt the cause of the shipped malts having got into such bad repute in the London market. It is to be hoped that the country maltsters have by this time discovered their error, and that they do not now practise the injurious system of watering (or liquoring, as it is called) their malt after its being taken off the kiln. The better price they would be enabled to obtain by the production of a really good article, would more than compensate for the profit arising out of any little increase in measure, which they might have formerly realised by their liquoring.