American Handy Book of the Brewing, Malting, and Auxiliary Trades/Storage Cellar Operations
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.
 Storage Cellar Operations
The beer is ready for tanking when the principal fermentation is virtually finished. The marks by which that stage can be detected are the following:
1. Decrease in the indication of the saccharometer should still be from i1,, per cent to 4'0 per cent during the last 24 hours.
2. The beer should have a good cover of fine, more or less dark foam. This protects the beer from contamination by contact with cellar air; therefore the cover should not be skimmed off more than once during or after the collapse of the Krausen.
3. The temperature of the beer should be 39° F. (3° R.). This temperature is brought about by attemperators in the fermenters, or by running the beer from the fermenter to the storage vat through a cooler.
4. The beer should show a good break in glass. Held against the light, the small sample glass should show a lumpy condition of the yeast, balled up in little clots, between which the liquid in a thin layer should show translucent.
5. The yeast should settle in the sample glass at cellar temperature within 24 hours, the beer becoming entirely brilliant. The yeast should not settle on the sides of the glass. In a warm room it ought to settle in 3 to 4 hours.
6. The beer should look black when the cover is blown aside, showing that the yeast has settled well and left the liquid comparatively clear.
7. The beer should still contain some sugars, i. e., should not be completely fermented, in order to enable secondary fermentation to take place. During the previous 24 hours before tanking there should still be a slight attenuation.
8. Beer for export purposes—bottle beer—should not be allowed to settle too much, but rather be racked "green" than clear ("lauter").
Before running the beer into the storage vats, the foamy head should be skimmed off with care, and then the liquid pumped without the least concussion or agitation of any kind.
The beer should be distributed into different Ruh tanks in order to secure a more uniform product both as to appearance and taste.
 On storage ("Ruh").
Storage, "Ruh," is that stage in which the beer is kept after the conclusion of the primary fermentation and prior to final clarification for the trade package.
The objects of resting the beer are to eliminate certain suspended matter, like yeast, securing greater clearness, and certain objectionable matters, like proteids, securing greater durability, especially in pasteurized bottled goods.
During the "Ruh" or storage period there should be a slight progress of secondary or after-fermentation. The residue of maltose and part of the malto-dextrin are fermented by slow degrees, the amounts of carbonic acid and alcohol increasing.
The yeast settles the more quickly, the less sugar there is present and the smaller the storage vats; and proteids are the more thoroughly eliminated, the better the mash was peptonized, the lower the storage temperature, and the longer the period of storage. Hence, long storage at low temperatures enhances the stability of beer after pasteurization.
Starch particles do not settle on Ruh. Nor can dependence be placed on improving the beer through long storage in respect to number of bacteria it contains. On the contrary, bacteria may increase during storage.
Low temperatures, while the beer is in storage, is necessary to precipitate the proteids and to check the development of bacteria.
Keep the storage cellar as near to 32° F. (0° R.) as possible.
If the beer becomes brilliant on Ruh. that is, if after-fermentation comes practically to a standstill, bacteria will develop more easily.
If the beer is to be stored for a long time it should not be allowed to become so clear in the fermenting vat as when an ordinary beer is produced, but should. be run into storage casks while still "green."
If the beer becomes clear on storage and we intend to store it longer, it should be krausened with 3 to 5 per cent of Krausen beer and pumped into another Ruh tank. Another plan is to let the principal fermentation proceed as far as usual, and subsequently run in some Krausen beer while the beer flows to the storage vats. This plan is recommended for beers designed to be very brilliant and remain in protracted storage.
If it is desired to bring the beer quickly on the market (city beer), add chips to the storage beer and also isinglass for preliminary fining.
For bottle beer, a high attenuating, slowly clarifying yeast should be employed.
For keg beer, a low attenuating, rapidly clarifying yeast is more suitable.
Export bottle beer should be stored three months; export draught beer six weeks.
During the storage period, hop-oils are partly converted into resins, the hop aroma diminishing accordingly.