American Handy Book of the Brewing, Malting, and Auxiliary Trades/Chip Cellar Operations
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This article represents a section of the classic public domain brewing text "American Handy Book of the Brewing, Malting, and Auxiliary Trades" by Robert Wahl and Max Henius.. See the main entry on this book for general information and a complete table of contents. | 
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[edit] Chip Cellar Operations
Contents |
[edit] The beer in the chip cask.
When sufficiently matured in storage, the beer is run or pumped into chip casks, so called from a method of clarifying beer by means of chips (which see).
Treatment in the chip cellar has a twofold object.
1. To impart to the beer the necessary life, that is, a sufficient amount of carbonic acid gas so that it will foam properly when tapped. This is done—
- a. by krausening and bunging, or
- b. by charging with carbonic acid gas directly (carbonating); or
- c. by both krausening and carbonating.
2. To make the beer brilliant. This is done—
- a. by the addition of chips.
- b. by the addition of isinglass.
- c. by filtration.
[edit] Kraeusening.
This consists in the addition of Krausen beer, that is, young beer in the first, or Krausen, stage of fermentation, 24 to 44 hours after pitching, according to pitching temperature and amount of pitching yeast used. As to amount of extract and other constituents it differs but little from fresh wort, hence it changes the composition of the ripened beer. While the addition of Krausen beer will cause fermentation to continue in the chip cask owing to the presence of fresh yeast, all of the sugar introduced by it will not be fermented.
The effects of krausening, therefore, are:
1. The krausened beer will have a higher percentage of extract, especially sugar. This has the effect of impairing the durability of draught beer, sugar being favorable to the growth of yeast.
2. The krausened beer will contain a larger amount of hop-resin, the taste of the beer is accordingly changed, Krausen beer being sweeter on account of sugar and more bitter on account of hop-resin.
3. The krausened beer will contain more proteids which will impair the durability of bottle beer. Use sugar Krausen for bottle beer.
4. The krausened beer will contain a smaller percentage of alcohol.
5. The temperature of the beer will be raised slightly owing to the revival of fermentation and the higher temperature of the Krausen.
6. Carbonic acid will be generated by the continued fermentation in the chip cask, which gas accumulates in the beer after bunging.
7. Young yeast cells are added.
The more energetic the cask fermentation, the more easily will the beer clarify. The young, vigorous yeast cells readily form clusters or lumps of yeast which will envelop, and, upon settling, carry down with them the smaller ones, together with bacteria and other suspended matters; thus, in part, at least, promoting clarification.
Krausening is based on a principle similar to that which leads English brewers to "prime" beer in the trade casks by adding a strong solution of cane or invert sugar.
[edit] Amount of kraeusen
This is governed by the properties desired in the finished beer.
For shipping beers—draught and bottle beer (steamed)—that is, beers of which durability is required, not more than 8 to 10 per cent. For common draught beer, 15 per cent of Krausen is generally used. These amounts vary, however, with the demands of the trade. In some cities as much as 25 per cent of Krausen is added regularly to the city beer.
Where the taste is too bitter, use more Krausen with less hops. Where the taste is flat, also use more Krausen, but have them hopped as usual. If a beer is stubborn of clarification use more Krausen.
Let the Krausen foam work out of the bung-hole for three or four days. If the beer is bitter, continue for eight days.
The formation of a Krausen cap over the bung-hole indicates that the Krausen are working properly.
[edit] Clarification of beer.
Matter remaining in suspension at the end of the storage period is eliminated by mechanical means. First among them is the introduction of chips.
[edit] Beer chips.
"Beer chips" or "clarifying chips" are pieces of wood so cut as to present a maximum of surface with a minimum of volume and weight.
Chips are made of varying lengths, breadth and thickness. Some brewers favor the very thin, curly chip, others prefer the straight, thicker and smooth chip, others again the corrugated chip. Metal chips have also been introduced, but since it is known that certain metals will produce cloudiness in beer, they should be employed with caution.
The chips clarify through the force of adhesion exercised by the surfaces of the same upon the small particles of matter suspended in the liquid.
[edit] Preparing chips.
Chips from young hardwood, beech or maple, are more effective than chips from old or soft wood. The wood should be well seasoned, i. e., well dried before cutting it into chips. The chips should then be boiled in plenty of water to remove coloring matter and woody taste, and one pound of soda is taken per barrel of water to remove the resin and make the wood more porous. Boil again with one-half pound of soda per barrel, a third time with one-quarter pound per barrel, then with water alone. If, after boiling for some time, the water remains colorless and without taste, and reacts neutral, the chips, after cooling, are ready for use in the chip cask.
Beer can be run twice on the same chips without removing them, then take them out and wash with cold pure water. After running beer on them twice again, wash them, first with cold water, and then with hot water, or boil them.
If the beer is infected, the chips must be removed each time after racking, and boiled each time after washing with cold water.
If chips that have been used are to be dried, they should previously be well washed and sprinkled liberally with a solution of bisulphite of lime.
[edit] Number of chips used.
The number of chips to be put into the beer depends largely upon the degree of haziness of the beer. As a rule, the number should be the greater, (1) the younger the beer, (2) the more particles in suspension, (3) the finer the particles in suspension (bacteria, proteids), (4) if no filter is employed, (5) the larger the quantity of isinglass employed. Without filter the number of chips need not be more than 50 per barrel. If beers clarify with difficulty, use double that amount. With filter, use 5-20 chips per barrel, according to size of chip cask.
[edit] Fining the beer.
The process of brightening which proceeds naturally in storage, is further assisted artificially by fining the beer by means of substances which will rapidly precipitate suspended matter. For this purpose prepared substances that contain animal gelatin are used. Such substances are obtained from fish sounds or from calf hide.
[edit] Isinglass.
From Fish Sounds.—These are the cleaned and dried swimming bladders of fish generally, principally of the sturgeon family; in the United States, from the hake. In the process of manufacture, they are first soaked in water, then rolled, and in rare instances starch is added for better appearance—gloss—and finally dried. This isinglass comes into the market in the form of thin shreds or ribbons. It varies in color from a deep yellow to almost white. There should be no odor or taste indicating decay.
From the Hide of the Calf.—This isinglass is manufactured according to Wahl's process. (See Brewing Materials.)
[edit] Preparing the finings.
There are two principal modes of preparing the article, as supplied by the dealer, for use in the brewery.
Warm Preparation.—Soak one pound of isinglass in l 1/2 gallons of cold, pure, soft water, renewing the water until every trace of odor has disappeared, washing the isinglass in the mean time by rubbing it lightly. At the expiration of about an hour add one-fourth pound of tartaric acid—for fish sounds—and keep stirring until no lumps are left. Add an equal quantity of boiling water, rouse well, mix with an equal quantity of beer, stirring to an intimate mixture, pour into the bung-hole of the chip cask, and stir gently.
With the tartaric acid the isinglass ought to swell considerably, and readily dissolve in the hot water. It is not advisable to dissolve it by steam, or to boil it, as the heat destroys the isinglass rapidly, particularly in the presence of acid.
Cold Preparation.—Soak in cold water and add acid and hot water, the same as for the warm preparation. When dissolved, add four gallons of cold water, rouse well; add gradually more water, and repeat this at intervals for 48 hours, adding as much water as the isinglass will take up. A good quality will take 30 gallons of cold water and keep its gelatinous consistency. This solution is mixed with beer, poured in through the bung-hole, and the beer stirred.
The isinglass may also be gradually thinned down without previous solution by adding small quantities of cold water until up to 30 gallons are obtained.
When using the cold process an addition of sulphite of soda should be made as the gelatinous mass is likely to mould.
Sounds.—If the sounds themselves are used in the brewery, they are soaked in cold water which is poured off, after softening. Then add one-half pound of tartaric acid per pound of sounds; when well softened cut up by passing through a sausage machine. Add cold water gradually, allow to soak thoroughly, and prepare warm or cold as above.
Wahl's Process Isinglass.—This does not call for tartaric acid, but after properly soaking in cold water (one pound per one and one-half gallons) for one hour, should be dissolved in hot water, after which it may be treated on the warm or cold plan like fish isinglass.
[edit] Operation of isinglass.
The process by which the isinglass acts is as follows: The gelatin contained in the isinglass dissolves in warm water and precipitates in flakes when cooled in beer when the solution is sufficiently thinned out, but in lumps, when the solution is too concentrated—therefore the cold preparation is more effective than the warm. The flakes gather up the particles in suspension, carrying them upwards during the escape of carbonic acid gas—before bunging—and settling to the bottom with them, after bunging.
Prepared warm, the finings contain the gelatinous matter in true solution which, on addition to the beer, becomes insoluble, and settles in the form of a net enveloping the suspended particles and carrying them to the bottom, leaving the beer bright.
Prepared cold, the gelatinous substances are only in suspension and very minutely distributed, being insoluble in cold water. The more and the thicker a jelly the isinglass yields, the better is its quality for brightening the beer.
The quantity of finings to be used is dependent upon the extent and stubbornness and the nature of turbidity, and whether a filter is employed or not. Without a filter, use one pound to 40 to 60 barrels prepared warm, or one pound to 100 to 150 barrels prepared cold. When using a filter, one-half of this amount will be sufficient.
[edit] Bunging.
After fining, the beer is bunged, that is, the bung-hole of the chip cask is closed tight for the twofold purpose of enabling the secondary fermentation which has been going on alt the time, to charge the beer with the requisite amount of carbonic acid gas, and of promoting the sedimentation of whatever particles may still remain to cause turbidity.
If a bunging apparatus is used, the beer is usually bunged directly after adding the isinglass. If not, it is bunged as soon as it has become moderately fine.
After bunging, the carbonic acid gas generated in the chip cask cannot escape. The beer grows richer in carbonic acid gas and exerts a pressure on the inside of the cask. The more carbonic acid is generated, the higher will the pressure rise. The higher the bung pressure, the colder the beer, and the higher the percentage of extract, the more carbonic acid will accumulate in the beer.
The augmenting pressure in the chip cask facilitates the precipitation and settling of particles in suspension.
When not using racking apparatus, beer should be bunged with from 4 to 5 pounds' pressure, and rather less with racking apparatus. If the beer is bunged with more than 5 pounds' pressure it is apt to foam, if not very cold, when racking.
If the beer contains too much carbonic acid gas it will not hold the foam so well as if it had its proper quantity. If the beer contains too much carbonic acid gas the individual bubbles that make up the foam will be larger than if the foam is creamy, and breaking up more easily, the foam will collapse quicker.
[edit] Racking.
The finished beer is racked off, that is, run into the trade packages (barrels, kegs, etc.).
This is done by means of air pressure, the racking bench usually standing higher than the chip cask, a steady flow of beer under an invariable pressure should be maintained, avoiding jars or concussions, sudden stoppages, etc.. as otherwise too much carbonic acid gas will be lost and the yeast might rise in the chip cask, making the beer turbid.
The quantity of carbonic acid gas that beer contained at various stages was found to be (laboratory of Wahl & Henius) :
| After principal fermentation | 0.20 per cent. |
| After two months' storage (in lower layers) | 0.35 per cent. |
| After racking from storage in chip cask | 0.28 per cent. |
| Before racking from chip cask | 0.40 to 0.42 per cent. |
| In the kegs | 0.35 per cent. |
| In the glass | 0.28 per cent. |
If the beer contains less than 0.30 per cent of carbonic acid in the keg or bottle, or less than 0.25 per cent in the glass, its taste will be flat.
There are modern devices for preventing foaming while racking by maintaining a counter-pressure on the flowing beer, yielding to the forward pressure sufficiently to allow the liquid to flow, but offering too much resistance to allow foaming. This is applied both to kegs and to bottles. In some cases the counter-pressure is exerted by carbonic acid, preventing contact of the beer with atmospheric air until the trade cask is tapped, thereby minimizing the chances of infection and adding to the stability of the product.
[edit] Chilling the beer.
It is advisable, whether a racking device is used or not, to chill the beer on its way from the chip cask to the filter, reducing the temperature of the beer below the freezing point of water. If beers contain an abnormally high percentage of proteids the low temperature may render them insoluble, when the filter may remove them, this process yielding a more stable beer when bottled and steamed. If beers contain but little proteids the time of passage through the cooler is too short to precipitate any appreciable amount of them.
[edit] Carbonating.
By charging the beer with carbonic acid (carbonating), the detrimental influences of krausening are avoided. It is difficult, however, to treat beer uniformly according to this method, or to produce beer with creamy head without addition of Krausen or sugar solution at the same time.
The carbonic acid in carbonated beers is generally introduced into the beer on its way from the chip-cask to the filter. It has been found impracticable, if not impossible, to carbonate Ruh beer from the storage tanks directly, one reason being that in such beers the carbonic acid is not uniformly distributed, the amount being larger in the bottom than in the top layers. In order to be successfully carbonated the beer is usually run into a chip cask where a small percentage of Krausen is added, and after bunging long enough to raise a slight pressure it is passed through the carbonator.
[edit] Filtration.
The latest and a most efficient artificial aid to clarification is the beer filter (see filters). It has come into general use of late years. The beer to be filtered need not be so brilliant in the chip cask as where no filter is used.
The process of filtering beer consists in forcing the beer, generally by means of air pressure applied at the chip cask, through one or more layers of compressed fibrous material, called filter-mass, which commonly consists of wood pulp or paper pulp. The thicker the layer of pulp, and the stronger it is compressed, the more effective will the filter be in removing turbidities, but the slower will be the process of filtration. By means of filtration yeast cells, both of culture yeast and the different varieties of wild yeast, and mycoderma cells can be removed. If the filter material is of fine texture (mixed with asbestos fiber) and compressed very hard, bacterial and proteid turbidities may be effectively treated, whereas starchy turbidity, owing to the minuteness of the particles in suspension, cannot be removed by filtration.
The advantages of filtration are:
1. Greater brilliancy and consequent greater durability of the beer.
2. Saving in chips and isinglass, as well as the time, labor and utensils employed during that stage.
3. Doing away with beer remnants and their treatment, as a filter will allow the last residue of beer to be clarified and used.
The filter is inserted between the chip cask and the racking bench, the beer in its flow from the former to the latter being forced through the same.
[edit] Filtering operations.
Beer should always pass through the filter under back pressure, as it will otherwise foam to such an extent as to preclude the proper filling of the trade packages.
In cases where there is no back pressure racking apparatus, it is advisable to place the racking bench higher than the filter and chip-cask in order to produce a natural back pressure action, and prevent foaming. For the same reason, and in order to got a uniform flow of the beer to be racked, the hose connecting the filter with the racking bench ought to be at least 50 to 100 feet long, and handled so as not to form any sharp corners. The hose may be of one to one and one-half inch diameter, according to the size of the filter and the racking capacity desired. By increasing the size of the hose the racking capacity may be increased considerably.
The filter ought to be put in a cool place and if practicable, in the chip cellar. Several pounds' pressure is necessary for the passage of the beer through the filter to the racking bench. The pressure from the chip-cask is regulated according to the flow desired, and is limited by the degree of air-tightness of the casks and their soundness, and may reach 10 to 20 pounds. During the time when the filter is not in use it ought to be filled with cold, pure, iron-free water, preferably condensed or boiled water.
After the connection between the chip-cask, filter and racking bench is established, and the valve of the chip-cask is opened, water is allowed to escape till beer appears, and the operation of filtering properly started. A little foaming invariably takes place at the start, and the foaming liquid is let off till the beer begins to flow clear. Where the hose leading from the chip-cask is connected with the filter an observation glass will do good service, which should be supplied with an automatic appliance for closing the filter inlet as soon as the cask is emptied and air gets access to the flowing beer. This is usually effected by a rubber ball floating in the liquid in the glass cylinder, and settling in the outlet as soon as the liquid is displaced by air.
Racking into barrels at the bench is started as soon as the beer begins to flow clear. Care should be taken not to interrupt the flow of the beer as the filtering material would otherwise give off some of the retained particles and cause turbidity for a few minutes.
[edit] Obstinate turbidities.
It happens, occasionally, that turbidities will not yield to the ordinary treatment, and special treatment then becomes necessary, which should be governed by the nature of the turbidity. In all cases of obstinate turbidity an energetic chip-cask fermentation, obtained by using more Krausen or sugar—or glucose—Krausen will be found effectual. At the same time the filter mass should receive an admixture of fine asbestos fiber, and be packed tighter to make it more effective. In this way wild yeast, bacteria and proteid turbidities are practically removed.
[edit] Starch turbidity.
When krausening the beer, add one quart of cold extract of malt ("Kalter satz") to 50 barrels of beer.
To prepare this cold extract of malt: To 20 pounds of crushed malt add 10 gallons of cold water, stir well for 10 minutes, allow to settle for one-half hour, pour off the liquid through a flannel cloth, bring the thick malt upon the flannel, and allow to drain. Of the liquid so obtained add one quart to 50 barrels of beer, preferably when krausening.
[edit] Proteid turbidity.
This form of turbidity often disappears upon warming the beer slightly, so that it often happens that it is cloudy in the cellar and has become entirely brilliant, when tapping in the saloon.
If the beer is very cloudy, sugar Krausen should be used for treating it (see Preparation of Bottle Beer).
Beers showing proteid turbidity should never be used for pasteurized bottle beer.
[edit] Abnormal taste and odor of beer.
There are times when notwithstanding all precautions have been properly taken—at least the brewer so thinks—the finished beer will possess an abnormal taste or odor, making it unsalable or at least less palatable. In such cases the important thing to do is to go over the whole course of manufacture in the most searching manner, to discover at what point a mistake was made, and take measures to forestall any repetition of the calamity.
For the immediate purpose of saving the imperfect beer and making it as sound as possible, prompt and drastic measures are required. Wherever possible, natural means should be employed, and the use of chemicals avoided, and in most cases it will be found that sugar, hops, a hopped sugar solution or more or less Krausen, more strongly or more weakly hopped, as the case may warrant, will prove effective, will cure the evil by returning, as it were, to an earlier stage and going through the various processes once more, with an eye single to the removal of the existing evils.
Among the tastes and odors of most frequent occurrence, representing deviations from the desired properties of the beer, the following may be mentioned:
[edit] Bitter taste.
This may be caused by the use of too much hops, especially Western or Pacific Coast hops, which are frequently found to give beer a rank, bitter after-taste if used in large quantities. Not more than half of the hops used should consist of Pacific Coast hops if the amount used is over one pound per barrel. Blending hops grown in different localities will be found productive of good results.
Other causes that may lead to an unpleasant bitter taste are, (2) boiling the hops too long; (3) leaving the wort standing too long in the hop-jack, or (4) the presence of wild yeast.
Treatment: The beer in the chip-cask should be treated with more than the usual amount of Krausen, less strongly hopped.
[edit] Sweet taste.
An excess of sweetness, or too mild a taste, may be caused by too much sugar, or an insufficient amount of hops.
Treatment: The beer in chip-cask should be treated with less Krausen, strongly hopped.
[edit] Hard or tart taste.
This is caused by too much acid, usually lactic acid; such beers are also difficult of clarification.
Treatment: The beer should receive an addition of soda—not bicarbonate of soda, as this will make the beer foam too much—to neutralize the acid. The amount to be added depends on the degree of acidity. In some localities the addition of soda to the beer is a general practice in order to give the beer a milder taste.
[edit] Onion taste.
This is due to a peculiar condition of the yeast, some varieties giving rise to it more quickly than others. The yeast may at the same time be entirely pure. Change your yeast at once, as soon as this taste or smell becomes noticeable.
[edit] Cellar taste.
Beers will readily take up any foreign odor, as when in contact with wood or pitch, poor varnish, or when the cellar air has a rotten or foreign odor like that of asphalt from a freshly laid floor, or tar from tar-paper used as an insulating material between the walls. Beer should, therefore, be carefully protected from contact with any such odor either in a vessel or in the air. A brewer should also avoid the employment of any substance in the cellars that has a foreign odor, for instance, substances for disinfecting or for cleaning purposes like carbolic acid and chloride of lime.
[edit] Stability of beer.
A beer which is expected to possess durability should have as few particles as possible in suspension. It should be perfectly brilliant.
A distinction should be made between:
1. Stability of pasteurized bottle beer (export bottle beer).
2. Stability of not pasteurized beer (export draught or local bottle beer).
If pasteurized beer becomes turbid, it is usually proteid turbidity, otherwise the beers have not been properly pasteurized. (See "Bottling Department.")
If keg beer or not pasteurized bottle beer becomes turbid, it is usually yeast turbidity.
If beer kept for a certain time shows any other turbidity outside of these two characteristic turbidities, it was not racked off in a sound condition, or it was infected by foreign organisms in keg or bottles due to improper cleaning of the same.
A sound beer filled into clean packages should not become sour or show a turbidity due to foreign organisms.
[edit] Pasteurization or steaming.
This is a process designed to give greater stability to beer. (See also "Bottling Department.") In general outline it consists in heating the finished beer in bottle to a temperature sufficient to kill such yeasts and other organisms as may remain in the liquid, excluding the light during this process, after which the beer is cooled.
The problem that presents itself in this treatment is to reach and hold a sufficient heat to accomplish the destruction of all germs without materially affecting the beer itself as to taste or brilliancy, or causing too much loss by breakage of bottles. Various devices have been constructed for steaming. No altogether satisfactory method of pasteurizing beer in kegs or casks or otherwise in bulk has yet found its way into brewery operations.
