BREWING 517 



With these very important facts before us, it is comparatively easy for the brewer 

 to determine his rule or mode of operation in the process of mashing. 



As the heats approaching to 167 tend to detract from the energy of the diastase, 

 such must of course as much as possible be avoided, it being known with equal 

 certainty that when malt-wort is allowed to drop its temperature to a heat approach- 

 ing 140, it is liable to acetancy, and more readily so, as the temperature recedes 

 below 140 ; about 120 being the most favourable to the change. 



Therefore it is advisable that the wort should reach the copper before such a tem- 

 perature is attained ; still further it is ascertained that the value of the desired trans- 

 formation in the malt-wort is best obtained with a temperature of about 151, also 

 that saccharification is promoted by agitation, and that the stronger the extract is, 

 the less is the danger of acetification. 



Therefore, in the first place, the brewer has to obtain a mash of 151 temperature 

 or thereabouts ; but he must do it with liquor as far removed below 167 as possible, 

 and when the goods are thoroughly mashed, 151 of heat should be maintained during 

 their clarification ; the wort should then be run from the mash-tun into a copper suit- 

 ably warmed beforehand, and should then be slowly and carefully heated up to 

 boiling, just by the time the subsequent exhaustion of the malt is completed by the 

 ' sparging.' 



In practice the following method will be found extremely easy, and safe in ope- 

 ration : 



Some time before commencing the mash, a sufficiency of boiling water is run into 

 the tun to make it as hot as possible, and immediately before commencing the brewing 

 this hot water is let off again into the underback, or the copper ; this being done, 

 the mashing liquor having previously been very carefully prepared, is let into the tun 

 under the false bottom, to the quantity of about one and a half barrels to the quarter 

 of malt, where it arrives at about 164 temperature ; when a sufficiency has been let in, 

 the grist is then added and thoroughly mashed, the infusion will then be about 150, 

 the temperature of reserve mashing liquor has been raised, and when the malt is 

 effectually mashed, a further quantity of about half a barrel per quarter is run in at 

 166, and thoroughly mixed up with the mash : the object of the additional liquor is 

 to raise the heat of the mash to about 152, after which settling and clarification are 

 requisite ; this usually occupies about two hours. 



The tun having been thoroughly heated before the admission of the mash, it does 

 not abstract the heat from the infusion, either during the operation or when it is com- 

 pleted, but materially assists to maintain the heat for a very considerable time ; with 

 a well-protected and covered tun it will do it for four hours if required, without 

 allowing the temperature to drop a single degree. 



This is of the greatest importance, for the wort leaves the mash-tun at about 151; 

 and as it is passed from vessel to vessel is immediately preceded by the hot water 

 from the vessel before it ; thus, in turn, each vessel is thoroughly warmed, and we need 

 hardly say most thoroughly cleansed, and being prepared in this way enables the 

 operator to get the wort into the copper before it can fall even to 146 or 147, leaving 

 the mash in the tun at such heat that all danger of acetification is entirely re- 

 moved. 



As the full value of the mash cannot be obtained by one maceration, recourse is 

 now had to ' sparging,' and to do this properly requires a little careful thought and 

 more careful management. 



In the operation of mashing every possible care should be taken that the infused 

 malt called ' goods ' when drained should lay perfectly level, otherwise the sparging 

 liquor, in running off, will form for itself courses through those portions of the mash 

 that offer the least resistance, and as a consequence some parts of the ' goods ' will 

 have treatment in excess of what is desirable, while other portions will be kept 

 with an imperfect sparge. 



The liquor for sparging should be of such a heat that it will, on penetrating the 

 'goods,' raise their temperature gradually from, say 148 or so, to 167 or 168 at the 

 close, this will generally be found sufficient to dissolve out of them all the tractable 

 portions of dextrine, &c. that are of any real value. 



_ It is advisable during the operation to allow the infused malt to drain two or three 

 times that the act of compression may express from them those portions of sweet wort 

 detained in the texture of each individual grain ; this will enable the brewer to obtain 

 the whole of the value that is producible from his malt, which may on that account 

 be treated with less pressure in the grinding; care in this latter particular will con- 

 siderably facilitate all subsequent operations, and give a brilliancy and superior 

 quality to the beer unattainable by other means. 



In drawing the wort from the mash-tun, no mechanical means should be neglected 

 that would aid in discharging it clear and bright into the copper, for all flocks and 



