This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
Barley ranks very close to wheat in nutritive power, and cooked barley meal, like wheaten flour, contains gum, albuminoids, starch, and dextrin. As compared with wheat, barley contains more fat, salts, and indigestible cellulose, less protein, and less digestible carbohydrate.
The employment of barley bread for food is of very ancient date, reaching back to the early days of the Greeks and Hebrews, but with the spread of the use of potatoes and the cheapening of wheaten flour, it has fallen into comparative disuse, and in the United States barley is mainly used to thicken soups and in the manufacture of beer. In some of the Pacific States it is fed to horses. Pearl barley is made by depriving barley corns of their outer shells or covering, and then subjecting them to rubbing between a single millstone and a sheet of rasped iron or wire cloth, a process which polishes the kernels and rounds them off.
Barley water makes an excellent diluent of milk and a demulcent drink for infants and invalids. For the latter it may be flavoured with lemon juice. It may be made as follows: Grind half an ounce of pearl barley in a coffee mill, add six ounces of water, boil twenty minutes, add salt, and strain. It should be made fresh daily and kept in a cool place. It is better than oatmeal water whenever the bowels are loose. The latter, made in a similar manner, is to be preferred when constipation exists.