Malt conditioning is a very simple process which consists of adding a very small amount of water to your grain bill prior to milling. The addition of water to your un-crushed malt results in more resilient grain husks. The husks take on a more “leathery” feeling. They are less dry and brittle, which means that they will remain much more intact during the milling process. Why would a brewer care to leave their grain husks more intact during the milling process? There are several reasons that would lead one to consider malt conditioning:
•Pulverized husks can lead to tanning astringency in beer
•Intact husks will create a more free flowing grain bed (fewer stuck sparges)
•You can crush finer to increase conversion efficiency without shredding husks.