A study of the admixture of amyloglucosidase-treated beer with other beer

Owades, J. and Bierman, G.W.

Abstract
With the advent of low-carbohydrate (amyloglucosidase-treated) beers, knowledge is required of the effect of admixing such beer with other ('regular') beers, as might accidentally occur, since about 35% of the carbohydrates of wort occur as unfermentable dextrins, all of which pass into beer, where they may be substrates for amyloglucosidase action. The rate at which glucose was released was measured when amyloglucosidase and regular beers were mixed and stored at 4oC and 20oC. With regular beer containing only 0.5% or 1.0% of amyloglucosidase beer, there was little increase (0.2%) in reducing sugar at 4oC over 90 days and it was not detected by taste. At 20oC, more reducing sugar was formed, such that the change in 20 days was equivalent to that occurring after 90 days at 4oC. After 90 days, these beers were sweeter, but all remained clear and potable. When 1% and 5% of regular beer was stored at either temperature in admixture with large volumes of amyloglucosidase beer, only minor increases in reducing sugars occurred over 90 days. These beers remained normal in appearance and were not detected by a taste panel.
Keywords: addition amyloglucosidase beer mixing type