Various sources indicate that lungwort was used as a substitute for hops by monasteries in Europe and Siberia in manufacturing a beer reputed to be both darkly bitter and highly intoxicating. It yields a permanent black dye when mixed with indigo. And because the pitted leaves resemble the surface of a lung, it was widely used in the treatment of pulmonary disease, wheezing and shortness of breath.
Before learning to recognize lungwort, I had perused Horace Kephart’s Camping and Woodcraft many times, but had consistently overlooked his entry on lungwort bread (vol. 1, pp. 324-325):
“There grows a green broad-leaved lichen variously known as lungwort, liverwort, lung-lichen, and lung-moss, which is an excellent substitute for yeast. This lichen is partly made up of fungus, which does the business of raising dough.
“Gather a little of it and steep it over night in lukewarm water, set near the embers, but not near enough to get overheated. In the morning, pour off the infusion and mix it with enough flour to make a batter, beating it up with a spoon.
“Place this ‘sponge’ in a warm can or pail, cover with a cloth, and set it near the fire to work. By evening it will have risen. Leaven your dough with this (saving some of the sponge for a future baking).
“Let the bread rise before the fire that night, and by morning it will be ready to bake. It takes but little of the original sponge to leaven a large mass of dough (but see that it never freezes), and it can be kept good for months.”
Some time back as a Thanksgiving treat, my wife harvested a patch of lungwort and baked several loaves of lungwort bread. The resulting bread had a pleasant tea-like aroma and flavor that I still remember. I’m thinking about requesting another go-round.