Not an adjunct per se, the hulls of oats are not fermentable, but they can be useful in the mash. The hulls provide bulk and help prevent the mash from settling and becoming stuck during the sparge. This can be very helpful when making wheat or rye beers with a low percentage of barley malt and barley husks. Use 2-4 qts of oat hulls for 6-10 lbs. of wheat, if doing an all-wheat beer. The barley hull is 5% of the kernel weight, so 5% of the adjunct weight is a good place to start. Do not exceed 3% by weight of the total grain bill or you will start tasting it as astringency in the beer.
