The conclusions, published in the July 26 Science , offer insight into the evolution of food preparation. They have even inspired a beer that made its debut earlier this month. Delwen Samuel, an archaeobotanist at the McDonald Institute for Archaeological Research at the University of Cambridge in England, examined the samples with both optical and scanning electron microscopes. Samuel could distinguish the different baking methods from the shapes of the microscopic starch granules. Heating causes them to swell and bend.
Enzymes make pits and channels in the granules.
From these features, Samuel deciphered several recipes for the bread. In one, the emmer wheat was allowed to sprout before being dried and ground into flour. The flour was then mixed with a lot of water, kneaded slightly, and baked, producing a dense bread. She determined a basic recipe for ancient Egyptian beer too, although it was much more difficult because of beer brewing's complexity. The variety of starch granules on the pottery shards showed that Egyptian brewers used a two-part process.