A pilot plant employing 9 kg malt with 25 l water as the main mash with 3.8 g adjunct either barley, maize grits, rice, sweet potato or maize starches plus 10% of the malt or added enzyme in 15 l water in a cooker, was used to study the changes in carbohydrates and nitrogenous materials in a double mash system. Analysis of carbohydrate was made using a column of Bio Gel P-2. Cooking of the adjuncts was carried out at various temperatures between 50 and 120 degrees C. The most effective was found to be 83 degrees C although little difference was found in the range 83 to 120 degrees C. Although variations were noted in the pattern of carbohydrates from the various adjuncts in the cooker, these exerted no effect when combined with the main malt mash. More than 60% of the soluble nitrogen present in the wort was preformed in the malt. These soluble nitrogen levels in the wort were closely related to the cold water extracts of the malts used. Rice, maize and the starchy adjuncts contributed only small amounts of soluble nitrogen to the worts. During enzymic mashing of unmalted barley, over 50% of the nitrogen in the barley was converted to soluble material appearing in the wort, although the composition of the nitrogenous materials in the worts derived from barley differed considerably from wort produced conventionally from malt. Most of the nitrogenous material formed during mashing was produced during the first 15 mins of the rest at 55 degrees C.
Keywords: adjunct brewing composition mashing saccharification wort