William Tizard Describes the Production of Blown Malt

In 1846, brewing writer William Tizard described the production of “blown malt,” a variety of brown malt made by maltsters in and around London. Germinated barley was spread in a very shallow layer on the kiln and exposed to an intense fire. The grain had to be turned constantly as the sudden heat caused the kernels to swell, crack, and sometimes jump like popcorn—a physical expansion that gave blown malt its name. Blown malt was closely associated with porter and was therefore also called brown malt or porter malt, although historical writers did not always use these terms consistently. Its rapid, severe kilning produced color and a distinctive toasted character but reduced its extract yield and enzymatic power. As porter brewers increasingly adopted pale malt and, after 1817, Wheeler’s black patent malt, blown malt declined from a principal brewing material into a smaller flavoring component and eventually largely disappeared from commercial brewing.