["The Chemistry of a Pint of Beer," the third in a series of popular science articles which Dickens and Leigh based upon celebrated Royal Institution lectures by Michael Faraday, shows the novelist-editor both working with one of his underlings (a staff-writer who specialized in expaining scientific and technological innovations to the Victorian Common Reader) and popularizing the work of a leading intellectual. Follow for a discussion of the novelist's complex roles as author and editor of Household Words. Philip V. Allingham, Contributing Editor, Victorian Web, transcribed the essay and translated it into HTML. GPL]

AT a late meeting of a very useful little Metropolitan Mechanics' Institution, which it is not necessary to our present purpose to name, a discourse on the subject above-mentioned was delivered by Mr. James Saunders, practical plumber and glazier, amateur chemist and natural philosopher.

Mr. Saunders commenced his lecture by observing, that much ado was being made just now about the Papal Aggression. This remark might appear foreign to his subject, but, in fact, led up to it; for the Pope of Rome had occasioned a fermentation in this country; and without fermentation there could be no such thing as that which he was about to have the pleasure of discussing—a pint of beer. He should say no more on the fermentation caused by the Pope, except that he hoped it would be followed by the usual results of that process as observed in brewing—sinking of the dregs; a going off of flighty volatile gas; and strength communicated to the good stuff in the barrel.

"For many of the observations I'm about to make, Ladies and Gentlemen," continued Mr. Saunders, "I shall have to apply to my notes; for which I'm beholden to our worthy Doctor, who is now amongst us; and I hope he'll excuse me for any mistakes I may make in pronouncing some of his words.

"In the first place, what is a pint of beer? 'Twopence,' says some of you, 'and a deal too much!' That's not the question. There's a great many beers. There's porter, there's heavy, or brown stout, and there's strong beer, and ales of ever so many sorts, and, then, there's swipes. Which is it to be? Well; please to take beer as meaning malt-liquor in general—a fermented drink made out of malt and hops. In a chemical sense, it don't much matter what tap it is. Here I may be asked, perhaps, what chemistry has to do with beer? Everything. Brewing's a regular chemical operation. Of course I haven't time to go into the whole art and mystery of brewing. I shan't attempt more than to give you some sort of notion of the science of that beautiful process. Well; now then we'll begin by inquiring what beer is made of?

"The answer most of you would make to this question, I take it, would be, 'Malt, hops, and water.' Some would add, perhaps, 'and a little isinglass, for finings.' That's what it ought to be made of, to be sure. But there's more things in ale and beer, ladies and gentlemen, than is dreamt of in your society—However, let us take beer as brewed simply of water, malt, and hops—what you may call Utopian Entire; though, mind, 'tis in the power of all of us to realise this salubrious and agreeable beverage, if so be as we've got the means, and will take the trouble ourselves, for to brew the same. "We'll say, then, that beer is made of malt, hops, and water. Very good. But now comes another query. What is water, and hops, and malt made of?

"First, what is water made of? Ah!—there was a time when heads, with big wigs on 'em, would have been shook at me for asking that question. I should have been thought mad—perhaps worse. But we live in better times, thanks be. You've been told afore, most of you, no doubt, that water, when quite neat, which you can't get except by distilling, of it, is made of oxygen and hydrogen, which are two sorts of gas; that is, when separated one from the other, as can be done by galvanism and other ways and means, and collected apart. Rain-water, fresh from the clouds, contains a little fixed air besides; the same air that comes out of soda-water and ginger-beer: what they call carbonic acid; namely, carbon, the same thing as charcoal, turned into gas by being combined, as the word is, with oxygen. What river-water contains depends a good deal on what goes into the river; the idea whereof may be left to imagination, with the hope it won't disorder the stomach. Same with well-water drawn from night sewers and churchyards. Besides these things, which have no business in water, both river and well-water contain various salts, more or less. There's carbonate of lime in 'em, carbonate of magnesia, carbonate of potash, now and then sulphate of iron, and so on, according to the soil they run through, or spring out of. Sulphate and carbonate of lime (in other words, plaster of Paris and chalk) cause water to be, what is called, hard; which is bad and wasteful for making tea; [498/499] but whether it is the worse or no for brewing beer is a dispute among brewers; and who's to decide when brewers disagree. It stands to reason that the quality of the water must have more or less effect upon the quality of beer; so, no doubt, the difference between the beers of different places depends, for one thing, on the kind of water they are brewed from.

"Next, as to the hops. The hop-flower belonging to the vegetable creation, is made of carbon, oxygen and hydrogen. Besides, there's a bitter extract in it, and likewise a drowsifying sort of principle, something like what there is in opium, called Humulin.

"Now for the malt. What is malt? Not many of you, I suppose, are such Cockneys as not to know that malt is barley, steeped in water, laid out on a floor, let be there till it is just about to sprout, and then dried on a kiln, at a heat high or low, according to the colour you want it to be; pale, or amber, or brown. Here begin the chemical manoeuvres required to produce a pint of beer. Malting is a process of chemistry that goes on in each grain of barley inside of the husk. What are the chemical ingredients of barley? Carbon, oxygen, hydrogen, and a little nitrogen. Malt has the same. But the difference between barley and malt is, that the carbon, oxygen, and hydrogen in the barley are in the shape of starch; whereas, in the malt they are in the state of sugar. In going to sprout, the barley gets sweet. The starch in it changes into sugar. Both sugar and starch have the same proportions of carbon, oxygen, and hydrogen ; twelve of carbon, ten of oxygen, and ten of hydrogen, in each—that is to say, water and charcoal. The difference between starch and sugar is thought to depend on the carbon, oxygen, and hydrogen in the one, being ranged together in a different way from what they are in the other. The 'ultimate particles' of carbon, oxygen, and hydrogen, being 'grouped together,' as the phrase is, in one way, form starch, and in another, sugar. So with gum, and several other things, that have the same elements—as chemists say—and in the same proportions as sugar, but differ from it in look and taste, and feel, and some other properties. It seems as though, whilst they are the same in point of chemical ingredients, they differ as to chemical texture. So they are the same things in different forms. All these things turn very easily into sugar. You can make sugar of linen rags, by boiling them gently in oil of vitriol. Dame Nature makes the sugar for us in malting. She always does make sugar in grain for the young sprout to start from. The change of starch into sugar by the name of the 'saccharine fermentation;' about which there's a curious fact I have to mention presently.

"The rest of the carbon, oxygen, and hydro-gen in the malt is in the shape of gum or mucilage, and colouring-matter. In the barley before it became malt, there was a small quantity of a substance called diastase. This contains the other chemical element of things that live and grow; animals and plants: nitrogen. There is very little diastase in barley: not more than one part in five hundred; but without it the change of starch into sugar could not be set a going.

"Now, Chemistry says, that there are such and such things in malt; but it does not follow that there may not be more. Those niceties in the composition of things that make flavours and perfumes, most of them, are not to be laid hold of or shown up by the art and instruments of philosophers, at least at present, and all we know about them, is by their effect on our palates and our noses: as the Doctor says, "on our gustatory and olfactory nerves." But, however, all this does not signify for our present purpose; and to understand the chemical part of brewing, we need only to look upon malt as so much grain turned into so much sugar.

"Seeing then that we know, in a general way, what water, and malt, and hops, are made of, and that we've got them to make beer with: the question is, how to use them for that important purpose. As I said before, I am not going to describe the process of brewing. Talking as I am to the wives and daughters of England, which latter will of course, become the former in good time, I should as soon think of lecturing on the darning of stockings or sewing of buttons on; to say nothing of the crochet which is so favourite a fancy just at present. No: I trust that the practice of brewing, and let me add of baking, and of cookery in all its branches, is as familiar to all young ladies as geography, astronomy, and the use of the globes, callisthenic exercises, elocution, dancing, and deportment; and if I pretended to teach them how to brew, the next piece of conceit I should be guilty of, would probably be, in the words of my learned friend the Doctor, "instructing my parent's maternal parent in the art of applying the power of suction, in order to extract the contents of gallinaceous ova." After which trying quotation, ladies and gentlemen, you'll perhaps allow me to take a sip of a beverage, which by name comes under the head of this discourse; however 'tis only the celebrated Adam's Ale: and no bad thing neither, when genuine, which is hard to get in these times, except in your cottage near a wood, if you happen to be so fortunately situated, in a sanitary point of view."

Having refreshed himself with a glass of water, the lecturer proceeded:—

"The first step in brewing consists in making an infusion of malt. Never mind about the physicky sound of this phrase. In other words, we will say mashing, if you like. But I use it because, in doctors' language, the word infusion means a liquor made by steeping a thing in hot water, to soak the goodness out of it, as counter-distinguished from boiling out the virtue; which last process is [499/500] called decoction. Infusion is enough to extract the goodness from malt; the goodness being the sweet, or sugar, whereinto the starch of the barley was turned, when it was changed to malt. It is a great point to make the infusion properly. The water ought to be of the right degree of heat, which, to make good beer, in a general way, is one hundred and seventy degrees by Fahrenheit's thermometer to begin with. A mistake in this particular may occasion the beer to turn sour, or become blinked, which when it used to be afore the thermometer was known, was often set down to witchcraft by the wisdom of our ancestors in the times of priestcraft and superstition.

"Water enough to stir and separate the malt, is first poured into a proper vessel—that is, a mash-tub;—the malt is now put into it and stirred about more water is then added at a greater heat the mash, or mixture of malt-and-water, is let stand for two hours, at the end of which it is drawn off, and is now called wort, or sweet-wort, in the vulgar tongue, and infusion of malt, or 'solution of the saccharine and extracted matter of malt,' by the learned.

"Now, to make wort it is not necessary that the grain used should all have been malted. About one part of malt mixed with two of raw grain in the mash-tub, will communicate the nature of malt to the whole quantity of goods. The raw grain or barley, must be cut into fine meal; meal powdered to dust, does not answer the purpose. This is a curious instance of 'saccharine fermentation,' and is the fact, concerning it, that I alluded to just now: how to account for it, nobody knows, I believe, farther than that through contact with the sweet of the malt, a movement takes place in the starch of the grain, between its particles of carbon, oxygen, and hydrogen; they altering their places with respect to each other, in such a way as to take that form of vegetable matter which we call sugar. But this is little more than merely stating a circumstance we can't explain.

"The starch in rasped potatoes even, may be turned into sweet or saccharine stuff, in the same way, by means of mashing or steeping with malt; and then a sort of beer may be made from it, and was made from it, so Mr. Booth says, in his "Treatise on the Art of Brewing," published under the superintendence of the Society for the Diffusion of Useful Knowledge. By his account, beer was so brewed from potatoes by a Monsieur Dubrunfaut, a Frenchman; and we are told it "resembled the beer which is made in Paris." Perhaps it may resemble, and something more, not a little of the beer that is sold in London, too.

"Brewers seem to approve of brewing from raw grain though I believe that, on their part, is against the laws, which however don't prevent private persons from so doing, if they choose. But one, who was a tolerable authority on the subject, William Cobbett, doesn't hold with it at all. He says, 'As to using barley in the making of beer, I have given it a full and fair trial, twice over; and I would recommend it to neither rich nor poor. The barley produces strength, though nothing like the malt; but the beer is flat, even though you use half malt and half barley; and flat beer lies heavy on the stomach, and of course, besides the bad taste, is unwholesome.' Cobbett's Cottage Economy, page 26, paragraph 38. How the truth may be, I can't say, but I can easily understand how the sort of sugar made in the sprouting of a seed, or 'germination,' may yield beer, different in point of taste and flavour from what that does which is produced in the mash-tub; the principles of flavour and taste being so very delicate, and perhaps, also, roasting or drying the malt may have some influence in the same particulars. I should be inclined to apply these remarks, likewise, to beer brewed from sugar and treacle, as it may be, and under certain circumstances is sometimes allowed to be, by the Excise. For the subject of a chemical discourse such beer is just as good beer as any other, and I've no objection to it whatever, as a lecturer ; but, as a consumer, if I am to have a choice, I should say, 'If you please, I should rather prefer the genuine original commodity, provided it's all the same to you.'

"When you have got your wort, or sweet-wort, the next step in brewing is to boil the hops with it: thereby making a decoction of hops in infusion of malt. By this operation you get out the bitter principle of the top; and there is no chemical change in it requiring particular notice.

"The liquor, strained from the hops, having been brought down in the coolers to the propertemperature, which is about seventy degrees, is now put into the tun-tub. In that respect it undergoes the great change that converts it into beer. This is called, fermentation. The process of fermentation is set a-going, as you know, by mixing yeast with the wort.

"Now, for fermentation to take place, it is, that besides carbon, oxygen, and necessary, that besides carbon, hydrogen, there should be nitrogen present in the liquor or substance to be fermented. Wort, from the small quantity of nitrogen still left in the malt, maybe made to ferment of itself with some trouble; but, to save that, the yeast is mixed with it. Yeast is the froth of a previous fermentation; and contains nitrogen enough to make the fermentation sufficiently quick. It is a sort of stuff in which you see a continual motion is going on. According to the German chemist Liebig, yeast causes fermentation by communicating its own motion, in a mechanical manner, to the particles of carbon, oxygen, and hydrogen, that compose sugar, dissolved in the wort, for instance. The hydrogen and oxygen, in sugar, as I said before, stand, in sugar, each to each, in the proportions of twelve, carbon; [500/501] ten, hydrogen; and ten, oxygen—though some reckon the two last at eleven. In ten, hydrogen; and ten, oxygen—though some reckon the two last at eleven. In fermentation these elements are dislodged, so to speak, from the position they hold, one to another, and then a re-arrangement of them takes place. Part of the carbon of the sugar unites with most of the oxygen so as to form carbonic acid, which flies off in gas. The rest of it combines with all the hydrogen and some of the oxygen, and becomes alcohol, or spirit, the production whereof in infusion malt, converts it into that generous and invigorating beverage on the philosophy of which I have now the honour of addressing you. Alcohol consists of four proportions of carbon, six of hydrogen, and two of oxygen. The proportions of these elements one to another in sugar and alcohol, as well as other things, are made out by separating one from the other according to art, in ways which it would take too long to describe, called Analysis. Well; you see fermentation is a sort of inward commotion ending in a new constitution; a sort of natural revolution in point of fact. Alcohol is formed in making wine, and all strong drinks, in the same manner as in brewing. A certain quantity of it, perhaps you may know, is even produced in fermenting bread. This is mostly lost in the baking; but some years ago there was a company formed to supply the Public with cheap bread, in the hopes of being enabled to afford to sell it at a lower price by collecting the spirit that is generally wasted. Whereupon a baker, who was up to snuff a great deal more than to chemistry, set up a shop where he professed to sell bread at the same rate as the company with the gin in it!

"The carbonic acid given off from beer while fermenting, is what makes it so dangerous to go down into vats, and sometimes occasions death by this being done without precaution.

"The proper plan is to send a candle down first; if there is much carbonic acid it puts it out. So, if you let a light down into the tun-tub, over the fermenting liquor. All the inside of the tub, above the liquor, while it is working, is full of carbonic acid gas; and if you dip a cup into the gas gently, you can ladle it out, and then if you turn the cup upside down over a candle you extinguish it as completely as if you were to pour water upon it, by that means astonishing the weak minds of spectators in a considerable degree.

"When the froth, or yeast, ceases to be formed on the surface of the liquor in the tun-tub, your wort has become beer, which you allow to get cold, and then put it into the cask or barrel. Here the fermentation still goes slowly on, as is shown by the yeast, that keeps gradually working out of the cask, till all the sugar, or as much of it as can be, is changed into spirit. Beer that tastes week, owes its sweetness to containing sugar not decomposed, or changed into spirit. Bottled beer is beer in which the carbonic acid, made by the decomposition of the sugar, or other vegetable matter in the beer, is pre-vented from escaping by being corked down.

"A liquor, to ferment, requires a certain amount of heat, not lower than between fifty-five and sixty-five degrees. It likewise grows hotter during fermentation; and as carbonic acid gas is thrown off at the same time, as from a fire, this makes fermentation seem somewhat like a burning or combustion. Only this, which is called the vinous fermentation, is a sort of burning independent of the air, the oxygen that feeds it being contained in the liquor.

"All fermentation in beer—or wine either—ought to stop with the change of sugar into spirit. But by being exposed to the air, or to the action of electricity, and some other causes, a. second fermentation is set up in it. The alcohol takes in oxygen from the air, and is changed into acetic acid, or vinegar. This is the reason why it is so necessary to have beer-casks thoroughly air-tight; for though what is called the acetous fermentation is interesting as a matter of science, to have one's beer turn sour is a great misfortune, in a domestic and economical point of view. What is termed hard beer is beer in which vinegar, or acetic acid, has begun to form.

"Good beer, then, is a mixture of alcohol and water, more or less undecomposed sugar, mucilage, and other extractive matter, carbonic acid, in greater or less quantity, and those delicate principles on which flavour depends, besides bitter of the hop. To these things there is added colouring-matter, which is given by the malt. In porter this is got by malt that has been roasted almost to charcoal. The carbonic acid in beer is what its briskness depends upon. The little bubbles you see in sparkling ale are composed of this gas, and without it the beer tastes flat. Old beer is beer wherein the vegetable matter has been wholly or mostly decomposed. In mild beer the decomposition has not been quite completed. It is a pleasing relish to a pot of beer to reflect on the chemical facts which that particular taste in it, which you fancy, depends upon.

"So much, ladies and gentlemen, for the chemistry of beer. Now for a word or two about the druggyistry of it. Instead of malt, sugar, treacle, honey, and other sweet things may be used—though contrary to law in the case of brewers—and are so, I fancy, more or less; without much harm. Wormwood, quassia, and other bitters, may in like manner, be employed in lieu of hops, without poisoning the consumer. Buckbean, or Menyanthes trifoliata, is another substitute—to be marked "dangerous." Aloes has likewise been used for the same purpose; but, being physic, I think it had much better be confined to regular medicinal purposes and not used to doctor beer with.

"I won't say, however, that beer may never [501/502] require a little doctoring. It is apt to be rather indisposed at times ; that is, to turn somewhat sour. When slightly afflicted with this complaint, a few egg-shells, which, in fact, are so much chalk, to absorb the acidity, may not be injurious. A little salt is supposed to make beer keep: there can be no great harm in that. Some have given their beer jalap, in the proportion of two or three ounces to twenty barrels; the reason for which proceeding is unknown; it may not do harm; but I don't see that it can do much good. Copperas is used for the sake of giving porter a frothy top. For this purpose, there need not be used more than would lie on a half-crown piece for a barrel. But I, for my part, should be disposed to think that so much copperas as would affect the head of a pot of beer, would be not unlikely also to affect the human stomach; and, I would, therefore, prefer not to have any copperas in my beer, if I knew it.

"However, this copperas, or sulphate of iron, is found in a great many springs of water, which the Excise does not prevent brewers from brewing from, although it forbids them to put the same quantity of copperas as what there is in those springs into the common water which they use. But this only proves that the law knows nothing about chemistry; and I'm afraid it don't know much more about philosophy and science of any sort. "The root of the sweet flag, coriander and carraway seeds, orange-peel, and other aromatics, are also used to give beer that flavour, which, if properly made, it would derive, without any such medical treatment, from malt and hops.

"Lastly, there are drugs which are put into beer merely to increase its fuddling power—Cocculus Indices, St. Ignatius's Bean, Nux Vomica, or Ratsbane, Opium and Tobacco. Concerning which, I shall only make the brief remark, that though in this age of enlightenment and civilisation, we must be naturally averse to capital punishments, I wish every brewer who puts any such stuff into his liquor, was condemned to drink his own beer, and nothing else, till he died—which I fancy he would in no very long time.

"I feel that I have not exhausted the subject of beer; but I am afraid I may have exhausted your patience. However, if my discourse has occasioned on your parts a feeling of dryness, the subject of it no doubt will suggest to you a ready means of relieving that uncomfortable sensation."

The lecture of Mr. Saunders was listened to with marked attention by a crowded auditory. At its conclusion, a teetotaller stepped forward, and begged to ask the lecturer's opinion on the relation of beer to health and morality? To which Mr. Saunders replied, that he considered it highly favourable to both, provided moderation—a virtue in itself—was observed in the use thereof. Too much of any good thing was bad; and this remark was as true of tea as of any malt liquor. [ends on page 502, top of right-hand column.]

Related Material


Leigh, Percival. "The Chemistry of a pint of Beer."Household Words (15 February 1851; 3 August 1850): 439-444, 498-502.

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Last modified 13 December 2008