An Investigation of the Relative Rates of Protein and Carbohydrate Modification of a Number of International Malting Varieties, Grown in Three Countries

Abstract

During malting, barley grains are steeped in water and then allowed to germinate under controlled conditions. This process is generically termed modification. The overall degree and relative proportion of starch, protein and cell wall modification during malting are critical in determining the quality of the final product. The modification process is greatly influenced by both the variety investigated and the environment in which the variety is grown. Currently, there are a large number of high malting quality varieties being grown worldwide that differ dramatically in the way in which they modify. These varieties are adapted to vastly different growing environments and often perform poorly when removed from their ideal environment. In this study, twelve international malting varieties were grown in Scotland, Canada and Australia in 2002 and 2003, in order to compare their modification profiles. They were malted in a Phoenix micromalter using a standard micromalting regime from each country. These regimes varied greatly, with large differences in both the number and length of steeps and the length of time for germination. Both the country and micromalter schedule had large effects on the degree of modification of the grain. The implications of these results will be discussed.