Studies of Mashing Methods for Beer Brewing with Sorghum

Abstract

Five mashing methods were studied; one stage decoction, two stage decoction, three-stage decoction, upward infusion and downward infusion. Reducing sugars from the various mashing methods showed that the highest mount of reducing sugar was produced in the second stage decoction( 13.6 ng/nl), third stage decoction mashing ( 13.8 ng/nl) and upward infusion mashing ( 1 3.6 ng/nl). Downward Infusion method yielded the lowest mount of reducing sugar ( 12.3 ng/nl). The two stage decoction mashing yielded thc lowest mount of protein ( 16.4 ng/nl) as against 17.2 ng/nl by three stage decoction and 18.8 ng/nl by upward infusion.It wcs therefore concluded that the two stace decoction mashing be recommended. The three stege decoction meshing was further studied by increasing the holding time at 650C and 700C for saccharification and dextrinization respectively fron 30 ninutes to 45 ninutes. It was found that there was sugar increase from 13.8 ng/nl to 18.6 ng/nl at 650 C and from 13.8 mg/ml to 17.6 mg/ml a t 700C. It is therefore suggested that the three stage decoction method may be made nore efficient by increasing the holding-tine. There was l i t t l e increase in protein in the wort. A change in the conventional tenperature regime of 6.50 and 70.0C to 60.0C and 72.0C showed that the conventional method produced more reducing sugar. I n c r e a s e i n mash concentration i n three stage decoction mashing showed a corresponding increase in the amount of reducing s u g a r s and p r o t e i n s produced.The upward and downward infusion methods were f u r t h e r studied by maintaining the holding time at the saccharifying t e m p e r a t u r e s , 6.50C and 62.50C respectively for 30 minutes, 60 minutes and 90 minutes. It w a s found that reducing sugar increase with holding-time in upward infusion while downward i n f u s i o n showed very little change. It is therefore suggested t h a t upward infusion method may be made more efficient by increasing t h e holding t i m e. There was no significant change i n t h e protein in the worts. Unmalted sorghum g r a i n s were found to contain amylases.It is suggested that i n the use of unmalted sorghum as adjuncts , t h e sorghum f l o u r should not be raised beyond 7.50C a t which temperature the amylases are destroyed.