Chapter 7

Malt Milling

Grist Analysis

A complete screen analysis of the crushed malt when milling should be made on a regular basis, with any adverse change in the mill’s performance warranting an immediate correction. The results of a sieve analysis help dial-in the grind of the grains used for mashing so that the maximum extract is achieved as the equipment use allows. It will tell the brewer if the grind is too coarse or if the grind is too fine. It is also important to note that there are other variables that can influence grist analysis. For example, mash/lauter tun design and geometry can impact how coarse or fine the grist needs to be as well as the type of mill used.

Sieve Systems Used in the Brewing Industry

The grain after primary milling can be filtered using various sized meshes. Proper mesh sizes can be selected from the following standard sizes as defined by the American Society of Brewing Chemists (ASBC) and the European Brewery Convention (EBC) as shown in Table 7.1.

Mashing Systems

Typically, the malt is ground coarser for infusion systems than those used in more intensive mashing programs, such as temperature-controlled and decoction mashes. An infusion mash tun requires barley husks remain relatively undamaged, because they are needed to provide a filter medium for the removal of solid material from the wort. A traditional infusion mash tun doesn’t have the rakes and knives that a lauter tun (a vessel specifically designed for wort separation) has to cut and lift the grain bed.

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