FACTORS GOVERNING THE MILLING OF MALT

A method has been developed using a laboratory 2 roll mill for reproducibly milling malt produced from European Barley (two-row). The procedure can be readily adapted to give grists of similar particle size distribution to those produced by either commercial four or six roll mills. Factors which were considered likely to affect the milling of malt were studied with particular attention to moisture level, the degree of modification, extent of kilning, influence of storage, differences in grain size and extent of steam conditioning. Most of these factors did exert an effect on milling. However, in the majority of cases the values needed to be outside normal commercial limits before substantial changes in milling performance were observed. Studies employing a laboratory mashing system have shown that by using malts containing c.a. 6% moisture it is possible to reduce wort separation times without affecting extract recovery. Steam conditioning can have a marked beneficial effect on the milling performance of malt providing the extent of moisture pick-up is carefully controlled.