Sugars from Starch

Appears in
On Food and Cooking

By Harold McGee

Published 2004

  • About
We come now to a source of sugar that is relatively new, but today rivals cane and beet sugars in commercial importance. In 1811, a Russian chemist, K. S. Kirchof, found that if he heated potato starch in the presence of sulfuric acid, the starch was transformed into sweet crystals and a viscous syrup. A few years later, he discovered that malted barley had the same effect as the acid (and thereby laid the foundations for a scientific understanding of beer brewing). We now know that starch consists of long chains of glucose molecules, and that both acids and certain plant, animal, and microbial enzymes will break these long chains down into smaller pieces and eventually into individual glucose molecules. The sugars make the syrup sweet, and the remaining fragments of glucose chains give the solution a thick, viscous consistency. In the United States, the acid technique was used to produce syrup from potato starch in the 1840s, and from corn starch beginning in the 1860s.