Mashing Without Malt

Can raw grains produce fermentable sugar without use of malted barley or another malted grain? Yes they can. While malt greatly facilitates the process, unmalted barley, or rye, can produce a fermentable mash.

See the discussion by Edward Skeates White, a nineteenth century authority on malts and malting, here, pp. 46-47 (The Maltster’s Guide, 1860).

Numerous books are in agreement, see e.g., Brewing With Raw Grain: A Practical Guide (1883) by Thomas Lovibond, a well-known brewing scientist of the same era. In his table at p. 73 he states he made a mash from 100% raw barley (“barley 100”). He gives the respective yields of this barley 100 as against various mashes that combine malted and unmalted grain. It is no surprise that the 100% unmalted version gives the lowest yield, but a wort is still produced and hence alcohol can be made.

Raw grains such as barley have an enzyme, b-amylaze, in small amounts but enough to convert polymer starches to maltose.

See also the extracts below (pp 133-134) from Horace Kephart’s Our Southern Highlanders, an early (1913) ethnographic study of the mountain Appalachians, addressing the mash for a mountain whiskey. He states if malt was available it was used with raw grains. If it wasn’t, due say to the “blockade” (British embargo during the Revolutionary War), a whiskey mash could still be made.

Perhaps, in this last case, the mountaineers were really making a corn malt as a sprouting, drying, and grinding of moistened corn are mentioned. Corn is probably different to raw barley in regard to the potential for self-germination. Raw corn must be heated to a high temperature, for example (cooked), to hydrolize the starches. Nonetheless the account is of interest as showing an artisan practice: no very sophisticated knowledge or equipment were needed to mash without sourced barley malt. It may be noted, too, that he explains fermentation can be achieved without adding yeast. Last year I devoted numerous posts to this aspect of “wild” fermentation.

White explains why this generally isn’t done in brewing: rawness of taste and instability (likelihood to sour or putrefy) of the wort. Stewart & Thomson make a similar point  (see pp 15-16) in their 1849 text on brewing and distilling. Lovibond claims in his book to offer methods that reduce the disadvantages of raw grain, but he clearly opts for a mixture (malted and unmalted) grain. Indeed, this is the basis of mass market brewing today for adjunct lager.