A Practical Treatise on Brewing/Electricity
ELECTRICITY.
On the injurious influence of Electro-chemical Action in the Process of Brewing.
It is now admitted that electricity is a powerful agent in all processes both natural and artificial. Wherever heat is liberated spontaneously in any process, it must proceed from one or more of the substances employed, acting upon others of a different nature; and when heat is thus produced, it may be supposed to proceed from chemical action, and thus evolving electricity.
Fermentation is a process of this nature, and the production of alcohol may be said to be partly effected by galvanic or electric action. Although fermentation has always been considered a very uncertain operation, and subject to every fluctuation of weather, we entertain some doubts upon that subject, and are also inclined to think that the causes influencing fermentation are not so little under control as may be generally supposed. If alcohol be the production of a regular chemical action during the process of fermentation, by disturbing the progress of that action, we will no doubt materially interfere with the results. If we find that in certain situations, and under certain circumstances, fermentation goes on much more regularly and uniformly than others, while using precisely the same kind of materials, we have a right to suppose that the want of uniformity must proceed from causes, which may be traced and removed. That the direct application of common electricity or voltaic electricity materially affects fermentation, there cannot be the slightest doubt; indeed it is established by several undeniable facts.
We shall, however, in the first place, insert an abstract of a paper on this subject, which was communicated by the author, to the British Association at their meeting in Liverpool, in 1837.
“I trust I may be excused in drawing the attention of the meeting of the British Association to a short notice of the injurious influence which electricity exerts on the fermentation of the worts of the brewer and the wash of the distiller. The powerful and injurious effects produced by this agent in the manufacture of beer, I endeavoured to point out, in a little work, lately published, on Brewing; which, although it has excited some notice among a few practical men, yet the subject has not received that attention which its great importance deserves. But I entertain a hope, that this matter will stimulate some members of the Association minutely to examine the nature and extent of the electrical agency, and, by well-devised experiments (towards which, if required, I should most willingly give any information or assistance,) succeed in convincing brewers and distillers of the necessity of studying the laws which regulate this all-powerful agent, in order that they may avoid its injurious effects in the manufacture of beer or spirits. Beer, to the industrious classes in this country, may be considered a necessary of life; and its wholesomeness and purity must, therefore, be of vital importance. The quality varies exceedingly in different parts of the kingdom, and what is considered good beer in one district, may in other parts be pronounced execrable. One great cause of the inferiority of beer and ale in the country, and of the great diversity of flavour, is the want of competition; it being only in the large towns that effectual competition exists. In the country districts there is little or none. The brewers have been long in the habit of purchasing all the public-houses in their neighbourhood, and these houses being limited in number, the labouring classes are prevented from selecting their own beverage, and have no choice but to drink that of the proprietors of the public-houses, who are also the brewers. Most of such beers are very imperfectly manufactured, and are usually foul and yeast-bitten, and have a very disagreeble, rank bitter, derived from the yeast left in the beer, instead of its being thrown out by a proper process. This bitter, although often mistaken for it, is very different from the agreeable and aromatic flavour of the hop. Yeast-bitten beer is particularly injurious to wet-nurses in the suckling of infants. In some districts, unsound, stale beer is the favourite beverage; so that, from long use, good, sound beer would not be appreciated, but rejected. A frequent cause of such inferior beers proceeds from want of proper attention being paid to cleanliness, which produces tainted worts, and consequently bad fermentations. I suspect, however, that it very often proceeds from electric or galvanic agency: the fermenting vessels, being very frequently sunk in the ground, are particularly liable to be affected by all electrical and atmospherical changes, as I have had many opportunities of observing. It is to the latter that I wish to direct the attention of the meeting. It has long been familiarly known, that thunder sours beer; but, though generally known, very few brewers have inquired into the cause, or adopted means to prevent this atmospheric, or other action, affecting beer during thunder-storms, or in the different electric states of the earth and atmosphere. The extreme rapidity with which the electricity is evolved during a thunder-storm, is strikingly exhibited in a distiller’s fermenting back. These fermenting backs are often made of cast iron, and either fixed in the earth, or connected with it by an intermediate iron vessel, employed in regulating the temperature. A very short time after a thunder-storm begins, or when the atmosphere is highly charged with electric matter, the appearance in the back altogether changes. The usual healthy character of the fermentation disappears; and it is now attended with a hissing noise and frothy head: and when samples are drawn and examined, is found to have risen, instead of fallen in gravity many degrees, and to contain 5 per cent. or more, of acid. Under these circumstances, the distiller has no alternative but to run off his wash into the stills, although they may be as high as 10 or 12 degrees above water, or occasionally of much higher gravity.
“But the chemical agency exercised by a highly electrical state of the atmosphere, is not confined solely to the fermentation of vegetable substances; it affects even the smelting of iron. It is well known to iron-masters and smelters, that in certain conditions of the atmosphere, and particularly during sultry summer weather, they can never, with certainty, calculate upon producing good, soft, tenacious iron, technically called No. 1.; it is much more generally the white, hard, inferior kind, called No. 3., or a mixture of Nos. 2. and 3. Now, in such circumstances, it will be found that the iron was melted during a thunder-storm, or when the air was highly charged with electricity. In these cases the ore shall be of the best quality, and all the manipulations belonging to the melting be carefully looked after, and even a much greater charge of coke be employed (the dernier resort of the melter), when apprehensive of hard, inferior iron, yet, notwithstanding all these precautions, the yield of iron is of the quality No. 3. The operating cause we consider to be electricity. The result of my observations, in different parts of the kingdom (and they have been pretty widely extended), is, that where the fermenting tuns have been placed upon baked Wooden bearers, and supported upon brick or wooden tiers, or columns, and every other precaution used to insulate the vessels as much as possible, the fermentations proceed regularly and progressively, and the beer turns out good, bright, and sound, and will keep so; but when the tuns are placed on, or embedded in the earth, or when electric action is induced by a chain of copper or metal pipes, making a complete galvanic circle, the fermentations are very irregular, and do not go through their changes in anything like order, and show only extremely high, light, and puffy heads. Frequently the attenuation or decrease of specific gravity altogether stops; and the beer becomes sour, or partially unsound, before leaving the fermenting tun. A rather singular attendant on this galvanic action in the fermentation is, the rise of the temperature of the worts in the fermenting tun will, in the course of one night, be 10 or 12 degrees, or more, and without a corresponding attenuation; while, in all healthy fermentations, there is a regular and proportioned decrease of gravity for increase of temperature. This is a point (although at present very little known or attended to) of the utmost consequence in regulating the proper quantities of yeast to be employed as a ferment, according to the specific gravity of the worts, and quality of the beer to be produced. A great deal of attention has of late years been bestowed on the mechanical construction of the utensils employed in breweries, in order to diminish manual labour and the waste of beer, and in making them quite automatic. In these improvements, unfortunately, too little attention has been paid to the injurious action of galvanism, or electricity. We know of one exception. An extensive establishment in London, well aware of the action induced by electricity, took the wise precaution, a few years since, when erecting fermenting tuns, containing 1400 barrels each and supported by iron columns, to have them insulated, from which they have derived great benefit. The same house, sensible of the importance of observing the atmospheric changes, has kept a meteorological journal for the last ten years; the observations being made three times a day—at four o’clock A.M., at nine oclock A.M., and at three o’clock P.M. In order to prevent the electric action on the fermentations of beer or wash, the vessels should be thoroughly insulated, and the mains, or pipes, leading to or from these vessels, should be thoroughly disconnected from them, by means of union screws, or perhaps still better, by a short hose of leather, or caoutchouc, or Indian rubber. By these simple means, the galvanic circle, otherwise formed by the metal pipes and cocks, &c. employed in removing the worts, refrigerating, or cleansing, will be broken, and a uniform, regular, and healthy fermentation, be produced. I have been inclined to think, that the great difference in the quality of wines which we read of, produced from vineyards within a short distance of each other, may as often be traced to some electrical action, caused by a bad arrangement of the fermenting vessels, as to any difference in the soil or quality of the grapes. I hope these few observations, brief as they are, will draw the attention of men of science, and also of the manufacturer, to the subject, believing it one of primary importance in this branch of the chemical arts.”
Mr. Faraday and Dr. T. Thomson considered the above suggestions particularly worthy of the attention of brewers and distillers.
We know that thunder-storms are caused by the different electric conditions of the earth and atmosphere. Fermenting tuns may be so situated, as to be affected by these different electric conditions. We know that milk in some dairies is soured and injured by atmospheric electricity, while in others differently arranged, no such effect is produced. Most brewers will admit, that beer of the same brewing, when sent out in casks, will remain sound in the cellars of some of their customers, while in others it will become acid.
A shock of electricity sent through any beer will speedily cause it to become sour.
Fermenting tuns, when imbedded in the earth, are very liable to be affected by the various conditions of atmospheric electricity.
Many instances of injury, from such causes, have come under the author’s observation, from which he selects the following:
In the summer of 1828, being called into a town in Surrey to superintend some brewings, he found that the fermenting tuns were imbedded in the earth, and at once expressed his disapprobation of this mode of placing them, and at the same time his doubts of any certainty of success, until the tuns were differently situated. No change of position could, at that time, be made. The fermentations, however, although by no means right, went on indifferently well for several brewings. But in a brewing, which was made on the 2d of July, the fermentation the next day (the 3d) became quite stationary, with regard both to temperature and attenuation: and although all the usual means were resorted to, none had the desired effect of forwarding the process. Having previously seen the same cessation of fermentation in an electrically excited state of the atmosphere, he had no doubt but that the extraordinary results proceeded from electric action, and stated his opinion to that effect to the brewer and others, at the same time predicting that we should very soon have a thunder-storm. As it is generally considered hurtful to let beer remain in the gyle-tun in a state of total inactivity, it was immediately cleansed by pumping it from the gyle-tun, into casks placed upon wooden stillions about eighteen inches high, where it soon began to throw out its yeast very well, and at the same time underwent an attenuation of 6 lbs. per Long’s instrument. Early the same evening a thunder-storm came on, which was of unusual violence.
The fact of beer of the same brewing turning out so differently in one cellar from another, is too well known to require any remark. It may often be owing to the same cause as the suspension of fermentation in the imbedded gyle-tuns; for when the casks are placed directly on the ground, without wooden bearers or stillions, the beer contained in them is more liable to electrical fluctuations than when the casks are better insulated.
The next case is of a different nature, and depending upon voltaic action. In 1835 some parties who had lately taken a small brewhouse near London, were surprised at the rapidity of their fermentations in certain stages; and also at the height to which the light yeasty or frothy heads rose at the same time. The author was applied to, and found that the gyle-tuns were lined with metal, which he then supposed to be lead, as is usual in such cases. A brewing was made for the purpose of ascertaining what was wrong. The worts, when gathered together, were 27 lbs. gravity per Long’s instrument, and were originally at a temperature of 58° F. in the gyle-tun, when a moderate quantity of yeast was applied. The fermentation advanced pretty regularly until about eight o’clock next evening. It had then advanced to a temperature of 62°, having a light yeasty head, and rather unusually pungent odour; it had also attenuated 4 lbs. in gravity. At six o'clock next morning it had attained a temperature of 78°, which is very unusual in so short a period. The light yeasty head having fallen a little during the night, was again rising, presenting a bluish-white appearance, which always denotes unsoundness; the gas was smotheringly pungent, and the beer had a very unusual styptic subacid flavour.
Calculating from the temperature gained (see chapter on Yeast) it should have been attenuated down to 7 lbs. It was only, however, at 14 lbs. The author concluded that the process had been improperly interfered with, and stated his opinion to the parties concerned. He was, however, assured that nothing had been done but by himself, and that every previous process had gone on in the same way. When the beer was cleansed, the tuns were again examined, when it was found they were lined with sheet copper, and soldered at the joints with tin. There was also a brass cock for cleansing the beer: so that two or three metals were in contact with the worts. On tasting the different beers in store, they had all a styptic, subacid flavour, such as had been perceived in the gyle-tun, which had, indeed, been the great cause of complaint. By some oversight the beer was not tested chemically for copper or tin, which doubtless would have been discovered in the beer.
A new wooden gyle-tun being recommended, it was immediately procured and placed as directed. In this tun no further difficulty occurred, the mentations went on regularly, and the beer turned out well.
The previous irregularity and styptic taste must, therefore, have proceeded from a portion of the metals being dissolved by the galvanic action, a necessary consequence of the mixture of metals in the gyle-tun.
In the next case which we bring forward the gyle-tuns were old and lined with lead. The worts ran from the coolers into the tuns by a leaden pipe introduced into the middle of the tun through the leaden lining. The tuns were also connected with a short main pipe (for cleansing the beer), by means of brass cocks and solder. The fermentation here was excessively irregular, sometimes going on very rapidly,—and ultimately arriving at what is called the “boiling” appearance, described in another part of this treatise: at other times coming almost to a stand still; and on all occasions after a certain stage of the process, acquiring an unhealthy faint odour. To prove to the parties that these irregularities arose from the mixture of metals in the gyle-tun and connected with it, two barrels of wort were taken and fermented in an open-headed butt, where the fermentation went on quite well, and without any irregularity whatever.
New gyle-tuns were at last ordered and put up; but even then. some little irregularities were perceivable, which were discovered to be owing to a different mode of conveying the worts (through pipes from the coolers to the squares) from what the author had recommended.
This having been altered, the brewings proceeded favourably, and no further irregularity in the fermentation occurred. The beer was approved of, and pronounced to be as good as any of the same gravity by two first-rate practical brewers in London. This shows what apparently trifling circumstances influence fermentation, where galvanism or electricity is concerned.
The next case we adduce differs from any of the preceding. Here there was no metal within the tuns, but brass cocks alone. There was a long leaden main pipe extending through and round the premises, in length, altogether, perhaps above 100 feet. In this main pipe there were various brass stop cooks, for different purposes. All the gyle-tuns were connected with this main by means of other pipes and brass cooks, for drawing off the beer for cleansing, thus forming a galvanic circle.
The complaint was, that the fermentations were all wild and irregular, and under no kind of control. The beer consequently was very much complained of, and invariably unsound. Two of the gyle-tuns were placed directly opposite each other, and connected as above described, with the main. When both these were charged with worts at the same time, the progress of the fermentation was certainly very extraordinary.
When fermentation had fairly commenced, and all other parts of the top were covered with the creamy froth, a circular space about eight inches in diameter, remained quite bare, directly above the discharge-cocks in both tuns. As the fermentation advanced, these were covered like the other parts.
The frothy top now rising, began to assume a variegated appearance. Directly above the discharge-cocks, that glassy-looking, bluish-white appearance, was perceptible, which always indicates unsoundness or galvanic action. This appearance gradually extended in a circular manner, about half round the tuns, in different directions, so as to form two opposite semi-circles. Soon after, the heads rose to such a height as to run over the top of the squares, without the possibility of preventing or controlling the action. The first thing done was to cut off the communication between one of the tuns and the main pipe. This had at once the desired effect. The fermentations in this tun were regular, and perfectly under control, and the ale produced proved very good. Notwithstanding this instructive fact, it was some time before the parties could be prevailed upon to cut off the other communications in the same way. They persisted for some time in brewing their common beer in the two tuns above mentioned, and the results were uniformly bad. Had the author’s suggestions been followed, every thing might have been remedied in a few days, as was afterwards proved, by cutting off the other communications between the tuns and main pipe.
I have thus given a few instances, out of many which could be adduced, of the decided and injurious effects of electricity, whether common or voltaic, exhibited during the progress of fermentation: effects which, when well understood, may be easily obviated or corrected.
The experiments of Gay Lussac also clearly prove the important agency of electricity in the process of fermentation. He found that wort to which yeast had been added, when placed in a vacuum, did not undergo fermentation, although all the circumstances were favourable excepting the presence of oxygen. But when an electric spark was passed through the fluid, the fermentation commenced vigorously. The effect here produced, he considered, was by the electric spark decomposing an atom of water, and thus liberating an atom of oxygen, which caused the process to begin. We do not mean to question the high authority of Gay Lussac, but his experiment does not altogether prove that the particle of oxygen produced was the cause of fermentation. It might perhaps be owing to a more general influence of the electric spark, which, in passing through the fluid, induced such chemical action of the different component parts upon each other, as were sufficient for producing fermentation.
We shall be able to prove, that after the process of fermentation has fully commenced, galvanic action will promote a much greater excitement than is desirable for the vinous fermentation; and we are also inclined to think, from the effects produced, that the acetous, instead of the vinous fermentation, is partially going on, or it might be better to say, that acidity is produced by voltaic action. M. Gay Lussac has distinctly shown, however, that a considerable excitement is produced by the electric spark, so as to occasion too vigorous fermentation, and we hope that very eminent chemist, by still continuing his attention to the same subject, may further enlighten us as to these results.
Having pointed out some of the errors most frequently committed in the construction of brew-houses, by the introduction of pipes consisting of various metals, (which we think has been proved to prevent the possibility of regularity in fermentation,) we shall now, in illustration of our remarks on electro-chemical action, describe a brew-house, in which there is neither a pipe nor pump, and in which every operation has gone on regularly and uniformly for years; and that also without a change of yeast.
We are inclined to believe that the locality was in a great measure the original cause of this brew-house being so constructed; and that it was thus advantageously built, more with the intention of saving money and labour, than from any knowledge of electro-chemical agency. This brewhouse is situated at a place called Pen-y-Bryn, in the immediate neighbourhood of Llangollen, a post-town on the great road between London and Holyhead. It is placed at the bottom of a hill, on a sort of slate rock, and is supplied with water from a fine spring, on the side of the hill far above the brew-house; thus giving a complete command of water, without pumping. Advantage has also been taken of the sloping of the rock, so as to save all unnecessary building. There is at the top of the premises a copper placed for the purpose of boiling the water used for brewing. Under this copper, at a little distance, is the mash tun, (commanded by this boiler,) from which the worts when ready are allowed to run directly into the wort-copper, which is at a little distance below the mash-tun. There is no underback. The wort-copper is sufficiently high to command the coolers, from whence the worts run into the gyle-tuns through canvass hoses and wooden shoots. And directly under the gyle-tuns is the cleansing room; so that neither pipe nor pump is necessary in the whole concern, excepting a short leathern hose for cleansing.
All this has been done by cutting away parts of the rock, so as to leave sufficient declivity for the different compartments.
Mr. Berry, the proprietor of this concern, adopted our system of brewing in March 1836, when he first commenced brewing there; at which time, we expressed the highest approbation of the construction of his premises in every department, and our opinion that nothing but want of care could prevent his being successful in his operations. We here subjoin an extract from a letter received from him, dated the 8th of July, 1839:—
“My Dear Sir,
“I feel much obliged by the compliment
you intend passing on the construction of my
brewery in your coming publication, and shall be
much pleased if I can in any way benefit you by
proving the success of your method of fermentation,
from which I have never varied. With the exception of the small quantity of yeast you brought
about eighteen months ago from London, I have
had no change since the first commencement here,
9th March, 1836. I am to-day brewing from the
same store, and my gyle-tuns work entirely to my
satisfaction. With the exception of a chance cask
or two, not being sweet, I have not had a single
cask returned for any fault the last two years.
Many other certificates of a similar nature can be readily furnished.
This distinctly shows that success in brewing depends, in the first place, very much on the construction of the brewhouse and utensils. When these, therefore, are properly constructed, and a correct system of brewing has been introduced and persisted in, nothing but want of attention or bad materials (such as defective malt and hops) used in brewing, can prevent unvarying regularity in the process of fermentation, followed also by unvarying uniformity in the quality of the beer.
Since our last publication it has been ascertained, that when placed in a negative vessel, worts will remain sound for a much longer time than when put into a positive vessel.
But when the gyle-tuns are in a negative state, the fermentations will go on very languidly, and occasionally become quite stationary; while on the contrary, under a different state of electro-chemical action, they will go on violently and uncontrollably, but without the due attenuation.