Barley and their hybrids and derivatives, barley contains gluten, which makes it an unsuitable grain for consumption by people with gluten-related disorders, such as celiac disease, non-celiac gluten sensitivity and wheat allergy sufferers, among others. Nevertheless, some wheat allergy patients can tolerate barley or rye. Barley is a key ingredient in beer and whisky production. Two-row barley is traditionally used in German and English beers. Six-row barley was traditionally used in US beers, but both varieties are in common usage now. Distilled from green beer, whiskey has been made primarily from barley in Ireland and Scotland, while other countries have used
Rye bread "maslin" (or variants of the name) was the bread of the better-off peasants for hundreds of years, in contrast to the white manchet bread eaten by the rich, and the horsebread eaten by the poorer peasants, which was made of cheaper grains including oats, barley and pulses. Wheat-rye breads, particularly light rye (sissel) and American pumpernickel, but also a combination known as "marble rye", are very closely associated with Jewish-American cuisine, particularly the delicatessen. The bulk of the flour is white wheat flour (often a less-refined form known as "first clear"), with a substantial portion of rye mixed in for