The Boiling of the Wort

By Edward Ralph Moritz

An expert in the field writes an article about boiling wort in the beer-making process. This book contains classic material dating back to the 1900s and before. The content has been carefully selected for its interest and relevance to a modern audience.

• Language: English
• Publisher: Read Books Ltd.
• Release date: Oct 25, 2011
• ISBN: 9781447490760

Book preview

Wort

THE BOILING AND COOLING OF THE WORT.

OBJECTS ATTAINED BY BOILING.

WHEN the wort has been prepared, it is boiled for some time with hops. The objects of this process are these:—

(a) The concentration of the wort.

(b) The extraction from the hops of their soluble constituents.

(c) The complete sterilisation of the wort.

(d) The coagulation of the albuminoids.

(e) The destruction of the diastase, and consequent fixation of starch conversion products.

(a) The concentration of the wort. In the event of our being unable to dispel a certain proportion of the water used in sparging operations by subsequent ebullition, we should either have to greatly lessen the amount of the sparge liquor, or else add an enormous proportion of sugar, unless we were content to brew beers of very low gravity. As a rule, during copper-boiling, about 25 per cent. of the wort is dispelled; and there is in addition a slight subsequent concentration during cooling, owing to evaporation at that stage. The structure of the copper, and the employment or non-employment of various subsidiary boiling appliances, will determine a greater or less evaporation; but about 25 per cent. may be taken as a fair average under normal conditions, and there seems no particular object in aiming at any greater degree of concentration. If we endeavoured to reduce the necessity for concentration by reducing the volume of sparge liquor, we should certainly lose extract; while any endeavour to keep up gravities by an excessive use of sugar, would certainly change the general character of the beer.

(b) In Chapter III. the constituents of the hops were enumerated and described. It is during boiling that we avail ourselves of the properties which they possess. In the first place we extract the tannic acid, or more strictly speaking a large portion of it; for spent hops which have been boiled twice—the total boiling period amounting to 5 hours—will yet be found to contain a certain proportion of this constituent. The function of the tannic acid is to precipitate certain nitrogenous bodies, which are uncoagulated by heat. These substances, i. e., those which are uncoagulated by heat but are precipitated by tannin, arc referred to in brewing literature as peptones, though there is no absolute evidence in support of these being bodies coming strictly under this designation. Reasons have been given for assuming that these particular bodies are undesirable from the standpoint of beer stability; their partial precipitation by the tannic acid of the hops, and their consequent separation in the hop back, would therefore be a point to the good, so far as the soundness of beer is concerned.

The coagulable albuminoids require no tannic acid for their coagulation, and these substances would appear to separate on merely heating and without the agency of tannic acid. But the uncoagulable albuminoids referred to would appear to require some