“A strawberry blossom does not moisten dry bread.”
The informant believes it means whatever is still is. He elaborated by saying that you cant fabricate it by adding anything. Even if you add the strawberry blossom to dry bread, it only complicates it. Does not fix the problem, it just adds to it. Does not remember where he heard the phrase from.
I believe that this phrase is about reality. You must make do with what you have and have patience. A strawberry blossom will eventually become a strawberry and you can make a moist jam with the fruit, but until then you will have to wait or make do with dry bread. I am sure this phrase could be substituted with any other dry blossom. The proverb teller must have heard this phrase from a place where strawberries are abundant. In a place where blueberries are plentiful it is likely that the phrase would talk about dry blue berry blossoms.