From The Brewers’ Journal – January 1898
By Frank Faulkner – Author of “The Theory and Practice of Modern Brewing” &c.
I am not desirous in this brief paper of initiating any controversy upon the thorny problem of salt, a question that has frequently provoked much difference of opinion among scientific authorities; the majority appearing to admit the service of mixed chloride compounds in brewing, while no less an expert than Dr. Stevenson, the well-known analyst to the Home Office, controverts the idea and speaks of chlorides as dubious, if not entirely detrimental saline bodies, when existing in beer to a greater extent than 50 grains per gallon.
(Editor’s note – there are 7000 grains in a pound or 437.5 grains in an ounce)
It is more in direct connection with the subject of yeast and the successful cultivation of this organism that I wish to enlarge upon the topic of water treatment, since, if I am not mistaken, brewers may easily drift into difficulty through the over-employment of calcium chloride, a saline body of undoubted service, both directly and indirectly in connection with beer palate – directly in the sense that it imparts distinct body to water in which it is dissolved and indirectly for the reason that the chloride spoken of constitutes a strong solvent for albuminous substances.
There are many writers indeed who claim for calcium chloride a kind of digestive power and argue that in exercising powerful solvent influence, it decides the assimilability of many crude albuminous bodies that yeast would otherwise reject, a view by-the-bye that I have broached more than once in reference to the service of sodium chloride when employed in conjunction with flour dressing, for otherwise we should find it difficult to explain the actual reverence that brewers have always had for this innocent substance. The problem then that I desire to deal with has primary reference to the well-known fragile character of modern yeast, this being generally indicated in the direction of a definite tendency to collapse or liquefy during storage. The liquefaction of yeast practically corresponds to the breakdown of physical structure, or a loss of vitality that enables the exceedingly dilute plasma or water itself, to escape from within the envelope, bag, or yeast cell, previously containing it, so that in result we find yeast-sloppiness in full evidence, as distinct from compact barm floating on the fluid, or existing as a sedimentary deposit. The escape of dilute plasma and revolutionized appearance of stored barm is speedily followed by the development of “micros,” followed in a short time by the more advanced forms of putrid ferments, much depending on of course upon the time of year and temperature of storage. The point therefore that I propose to utilize as a basis for my contention in connection with the water hardening is simply the present frequency of yeast collapse which was rarely evidenced years ago and which must undoubtedly be determined by some modern and unexpected influence.
So much has been written about yeast food, amides, peptones, para-peptones, and “toast and tea nutriment,” as a well-informed scientist has termed artificial dressing, that the majority of brewers explain yeast difficulties by sup0posing that modern malt does not yield the necessary proportion of soluble albuminoids to support the barm eventually planted, others no doubt regard the substitution of saccharine matters for malt extract as detrimental; while not a few complain that a skimming process favours yeast collapse, and that cleansing vessels (puncheons, unions, pontoons, or trade casks) tend to prevent it.
I am quite ready to admit that the question of malt character is of vast importance, but we must not overlook the fact that brewing materials yield saline matter of great moment, while if essential to the structure of barley, maize, hops, and so forth, these saline bodies are surely necessary to yeast, and herein lies the keystone of my present argument, for I am dealing with the question of water treatment, and wish to simplify the special problem in connection with calcium chloride, and strike a correct balance between possible service and deterrent agency.
The shortcomings of a mere infusion method of mashing are well known. The extract we secure under such circumstances depends almost entirely upon the character of malt employed, since we have no power of either directly modifying or controlling its proportional composition. It is generally admitted that few brewers have given any attention to the question of saline matters, and yet it is well known in continental breweries that in boiling the Dickmaische (third mashes) increased solution of phosphates results, with corresponding increment in acidity, owing to the presence of the decomposition products of gluten and casein bodies of the nature of acid phosphates.
Professor Lintner, too, has proved that English infusion worts carry much less phosphates than when advanced decoction is practiced, and that English grains notably hold the phosphates that are almost entirely absent in the case of decocted draff, a fact surely of remarkable importance.
I cannot dip further into this very interesting side topic, but submit that we do not in our infusion process secure the maximum, but far more likely the minimum, yield of necessary phosphates, the question naturally arising whether it is wise in practical operations to utilize saline matter exercising any potent decomposition power. I refer, of course, to calcium chloride, and may assume for example that in speaking of phosphate matters yielded by the material ordinarily empl0oyued in the production of beer we mainly secure thee in the form of soluble potassium phosphate, and it would be easy to prove that when coming into contact with calcium chloride speedy decomposition undoubtedly results with the formation of an insoluble calcic phosphate, the minute normal acidity of an English mash wort being quite inoperative I have pointed out elsewhere. The reaction named does not take place in acid solutions, but, on the other hand, does so readily enough when acidity merely ranges to the limit of 0·1 per cent, and although it is impossible to say definitely whether the specified reaction is normal during mashing, I am surely justified in basing my argument upon the strong inference that exists.
The late Dr. Hassall dealt fully with the subject in his well-known work on “Food,” and explained that, although gypsum or sulphate of lime might be regarded as a serviceable body, there was no absolute certainty that it existed in beer at all, since while we can easily determine the component bodies making up the ash of beer the chemical combination of them is by inference, and in this sense unreliable.
I may explain, however, that when calcium chloride has been used in the manipulation of brewing waters, none of it is found in the soluble saline bodies of eventual beer ash, but as an insoluble lime phosphate amid draff, a most suggestive fact, and one that ought not to be overlooked. More than one analyst has quite recently tripped over this very simple matter, for, in determining chlorine and calculating this in equivalent from as common salt, the analyst has evidently ignored the possible reaction spoken of, so that a beer, apparently rich in sodium chloride, may carry in point of fact a considerable amount of chloride of potassium as the direct result of transformation changes between the phosphates of original grain and the calcium chloride that I have now under consideration.
It may be somewhat puzzling to asset that grain of all kinds yields chloride of potassium in large quantity, but many advance chemists confirm the view that ordinary mash-tun material actually yields variable portions of K3PO4 and a small percentage of sodium phosphate according to the character of soil under cultivation, the analysis of endless specimens of beer proving the inference that calcium chloride is one of the chief artificial additions to brewing water at the present day, and that in being commonly employed we can readily account for the existence of insoluble calcic phosphate amid the mash-tun draff. The crucial question may now be considered, since, if the reaction between calcium chloride and alkaline phosphates takes place in the mash-tun, we should have but few phosphates in either wort or beer, the actual mash or draff of grain constituting a good filter bed, but if resulting after the passage of wort carrying both forms of saline matter from mash-tun to copper, and thence to fermenting vessels, we obviously face the possibility of a steady subsidence of insoluble CaPO3 during fermentation and beer cleansing.
I therefore suggest the question of phosphates as a new and complex problem for the skillful chemist to solve, and one that naturally requires the greatest accuracy of working detail, although practically comparatively simple, and worth of careful consideration non the part of operative brewers.
After many experiments, and by noting the results in connection with yeast in many large English breweries, I have gradually come to the conclusion that calcium chloride can, and does, play a double part. No one can dispute the value of the article as the agency of beer body, palate softness, tenacity of foam or froth, and direct service to yeast through solvent power, but the thoughtful brewer should study its possible, and indeed probable, action upon soluble phosphates of grain, since in doing this, he may readily discover one cause of yeast collapse that has never previously been hinted at.
I am of the opinion indeed that the assumed influence of calcium chloride may vary with every description of wort, or the way for instance in which the saline matters employed in a brewery for artificial water treatment are actually weighed up, dissolved and used, the action depending in no small measure possibly upon the ratio of wort concentration, and so forth. Let me sketch, for instance, a common example. The majority of brewers weigh or measure u the solid or liquid blend to decide a certain definite degree of hardness in the case of collected produce, but introduce this bodily into mashing liquor, which constitutes of course only a limited proportion of entire wort boiled off, so that in result they determine extreme hardness of mashing fluid, and a favourable opportunity for the calcium chloride of saline blend to decide the reaction that I have already described in detail. I suggest that some eminent chemist should deal as speedily as possible with this phosphate problem, since, if barley, wheat, maize, hops, and the other vegetable growths require soluble and assimilable phosphates in soil, I may fairly urge that alcoholic yeast, a vegetable organism in which al brewers are naturally interested, needs them also. The employment of calcium chloride too liberally may therefore need modification, and while no hard-and-fast rule can possibly be drawn at present, I should certainly advise brewing firms experiencing any yeast difficulty in connection with sloppiness of liquefaction to moderate the use of this lime salt, or, when employing it, to sub-divide the material over the entire length of mashing and sparging fluid, so as to minimize the certainty of the double decomposition referred to.
If we could only determine directly the course of these double reactions the service of calcium chloride might be accurately decided but so long as the inference of possible double decomposition is substantiated, as indeed it has been in my own mind by repeated -practical experiences, the careless and excessive employment of the calcium salt must be deprecated for obvious reasons in connection with yeast cultivation, for although encouragement might be found in the actual existence of phosphates in beer, I nevertheless express the decided opinion that the percentage would be very variable and always exceedingly minute in cases where yeast difficulties were in evidence.
To brewers working more or less constantly with yeast changes, the line of argument that I have adopted in this paper may appear scarcely deserving of attention, but to other who desire to not continuous growth of brewer barm in a state of purity and uniformity of type the statements should be instructive, for many within my own knowledge seem to be upon the horns of a dilemma, and, while realizing the beneficial influence of chlorides upon beer character, nevertheless discover by experience that yeast outcrops do not always correspond. If brewery yeast exhibits, on the other hand, improved physical formation through the employment of calcium chloride the debit influence of the lime salt must of necessity be counter-balanced by the exceptional character of the material employed in the mashing vessel.
The late Mr. Southby was a powerful advocate for calcium chloride employment, and more recent writers have adopted and enlarged upon his views, but in spite of this I argue that caution is necessary on account of the very common yeast difficulty that has puzzled the practical worker for years past, and more especially so, perhaps, when summer warmth favours natural degradation of barm.
If Dr. Stevenson is correct – and his standing as a public official is beyond comment – it may soon be necessary for brewers to limit the total chlorides in water hardening to 50 grains per gallon, to eliminate the lime salt, and determine hardness by relying upon sulphate of lime and kainite solution, although giving the preference perhaps to gypsum and salt in nascent form, as we find them in the various specimens of liquid saline solutions.
The service of chlorides in the mash-tun is acknowledged and freely admitted, salt for instance playing an important part in connection with digestion during fermentation, so that we shall probably not in the immediate future steady development of the policy that covers the employment of mixed salts, fairly represented as I have just said by blends of gypsum and kainite, instead of undue reliance upon one specific body even so valuable in one sense as calcium chloride is known to be.
Crescent City Brew Talk 