Gluten-free beer example: Sheehan, Evans & Skerritt, 2001). Brewers who produce low gluten beers are required to test every batch for gluten, and record gluten levels in "parts per million" ('ppm'). Although the barley hordein in such tests may not be detected, smaller pieces of these proteins, known as peptides, may remain and be toxic for celiacs. Those involved in gluten-free brewing, and others representing celiacs or those with other conditions that require a gluten-free diet, tend to be concerned that beer brewed using wheat or barley are not appropriate for those with celiacs or dermatitis herpetiformis, although the carefully controlled gluten
Rye bread "Lactobacillus" "sourdough" cultures lowers bread pH, facilitating growth of an acid-tolerant yeast strain, and helping gelatinize starches in the dough matrix. The byproduct of this approach is lighter breads. In areas where high-gluten hard wheat is readily available the need for a complex polyculture of bacteria and yeast can often be reduced or removed by adding a large proportion of hard wheat flour to the rye flour. Its added gluten compensates for amylase activity on the starch in the dough, allowing the bread to retain its structure as it bakes. The "deli rye" tradition in the United States is based