The Infl uence of temperature, steeping degree and time on the cytolytic modi fication properties of malt
The basic aim of malting technology is to cause a formation and activation of
enzymes with the help of a controlled germination which results in changes of the
endosperm of the barley kernel called modification. Endosperm cell walls present a barrier to the movement of hydrolytic enzymes that mobilize endosperm reserves. These have to be degraded before the reserves can be mobilized. A proper control of this degradation is essential for the production of good malt. Preece et al. stated physical condition of the grain constituents is ultimately the dominant factor in modification (4).
Use of industrial enzymes in the brewhouse
Industrial enzymes, prepared from microorganisms, find a variety of uses in brewing,
for example in mashing They are also used as analytical tools, for example in determining starch or ß-glucan. However, commercial enzyme preparations normally contain a range of enzyme activities and frequently vary in their compositions. The principal aim of the malting process is to activate enzymes present in the barley kernel and to induce the formation of others, which we need later in the brewhouse.
Importance of the beta-glucan solubilase during the production of wort
The ß-glucan solubilase is a cytological enzyme. During cytolysis ß-glucan is
dissolved from hemicelluloses of the cellwalls of barley. ß- glucan can lead to
difficulties during lautering and the filtration of the final beer.
Influence of pH adjustment during mashing on the quality of wort and beer
Every enzyme has its optimum pH and temperature. On the other hand the modification of the endosperm is influenced by the mash-pH as well. So the pH is an important factor witch does influence the mash and beer quality. Franke and Windish were the first people in the beginning of the 20th century which concerned with this fact. They wanted to compensate the disadvantageous characteristics of brewing liquor with a high residual alkalinity. The mash pH influences the lautering time, the leaching of the husks, the processes by wort-boiling-, the isomerisation of bitter substances, the formation of cold and hot trub and the pH decreasing during fermentation.
