Cuthbert Thistlethwaite wrote:
> My grandmother (almost 50 years dead now) made wonderful berry jams and
> put them up in one-pint size mason jars.
> I don't remember whether they were vacuum sealed or not, since it was
> not my job to open them as a small boy.
> What sticks in my mind however, was that she laid down a layer of
> paraffin on top of the jam in every bottle.
> Does anyone have a clue what the paraffin would be for?
> (This was in northern Wisconsin, which is on the cool side, so vast
> hordes of bugs and crawlers were not likely the problem she was solving
> with the paraffin seal.)
She did that as a lid to seal the jars; keep them from spilling if they
tip over, keep bugs out, and keep air out. Also, she probably reused
glass jars saved from peanut butter, store-bought jelly, and dried beef
and didn't have proper lids to fit. (I used to put up jelly that way
too, *many* years ago)
It's an obsolete method and not all that effective. What you don't
remember is the jars that molded or got full of ants because the seal
broke and she quietly threw them out.
Using proper canning jar lids and sealing with a boiling water bath is
actually cheaper these days, and you'll have much less spoilage.