Suzie, The Complete Book of Breads by Bernard Clayton, Jr. (Simon and
Schuster, 1973 ed.) has three recipes featuring barley flour. One is a
quick banana bread and also uses rice flour; another quick bread uses
barley flour as the only flour and is flavored with orange juice and
peel; the third is called Rieska and is a non-yeasted flat bread. Mr.
Clayton says, "There is something velvety soft about barley flour..." and
he says, too, "Rye flour ... can be substituted for barley with good
results," so you might want to try using barley flour in place of rye
flour in some of the recipes you already have. Hope this helps.
- Ron