I canned pints of salsa in September using an approved recipe, with
BWB. A jar was opened, partially enjoyed, and shoved to the back of the
fridge for maybe four weeks. When I took it out recently, it had a
weird rubbery quarter inch thick layer on top. What could this have
been?! It was not moldy or fuzzy, and didn't smell like anything
except, well, salsa. Obviously we didn't eat it, or the remainder of
the salsa. My husband suggested it was some yogurt-like growth. Any
ideas on what/how this happened?