| Popis: |
During an infusion mashing period of 1 hr. at 150° F. (65.5° C), “hexose carbohydrate” was extracted with an efficiency greater than 95% over the range of mash concentrations from 8 up to 42% from a number of malts tested, with the exception of a “high nitrogen malt” of relatively small diastatic power which gave satisfactory extraction only when the mash concentration did not exceed 33%. Over the same period, infusion at 145° F. (62.7° C.) or a modified Congress procedure gave this efficiency only at mash concentrations up to 16–25%. At these concentrations and using brewing malts of low nitrogen content, however, the modified Congress procedure gave slightly poorer recovery of hexose carbohydrate but slightly higher extracts than infusion at 150° F., owing to greater solubilization of nitrogen compounds and, probably, pentose carbohydrate. Extension of the mashing period to 3 hr. permitted extraction of almost all available carbohydrate by infusion at 150° F. or by the modified Congress procedure even at a mash concentration of 50%. Over this period at 145° F., however, extraction reached an acceptable level for brewing only at mash concentrations up to 33–42% and only when malts of low nitrogen content were employed. The fermentabilities of worts produced at 145° F. were greater than those of worts made at the higher temperature but were reduced to the normal level by restricting the time of mashing to 1/2 hr. and continuing the extraction by sparging at higher temperatures. |
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