"ljp" > wrote in message
...
> On Aug 16, 9:12 am, George Shirley > wrote:
> > ljp wrote:
> >
> > > I'm wondering if the two piece lids and water bath are overkill for
> > > jams and jellies. I'm pretty sure it works well for Ball et all.
> >
> > Not if you want your jams and jellies to be safe to eat and able to be
> > stored. Check out:http://www.uga.edu/nchfp/index.htmlfor more details
and the reasons
> > behind proper, safe canning methods.
>
> The argument for the double lid seems to be consistency which is
> reasonable. However, it doesn't get into why glass and rubber rings
> are unsafe. It would be nice to find instructions for the safe use of
> same and cautions, rather than a prohibition. ie should they be
> processed in a BWB.
Any high-PH food, like jam, if canned
and there is an air leak and the inside of the jar loses sterility, what
you get inside is a nice crop of mold. It's quite visible in the headspace
even before you take the top off the jar. Once the seal goes, they mold
as fast as a piece of fruit does that you would cut in half and leave in
the refrigerator. You don't get botulism, though.
I would assume that any -normal- person the second they tasted some
jam from a jar with a bad seal, they would think it tasted terrible and
be spitting it out, assuming that they were blind to the point that they
didn't notice the stinky sock smell or the white fuzz and black spots
all over the surface of the jam.
The unsafe part would be for the person who actually got past the
gag reflex and got the stuff down. Molds are a shotgun "food" if
there ever was one, reactions range from nothing to projectile
you-know-what coming out of both ends. It all depends on the
specie of mold that happened to become dominant in the jar and
how the victim's body reacts to it.
The traditional way of canning with the rubber rings and lids
(wire and bail) was to leave the jar, ring, gasket & glass
lid in boiling water, then when the jam was ready you quickly pulled
out the hot jar, and pulled the boiling jam off the stove, poured it
in, than banged down the bail and
gasket as quick as possible. The jam, being full of sugar, would
be above the boiling point of water and so presumably any air in the
headspace which was below the boiling point, would be heated above
the boiling point. You usually tried to have little headspace as possible
which would often mean extra jam squirting out and making a mess
when you banged down the bail
Of course, good luck with that if your jam happened to be very
frothy, none of this waiting for it to cool down then skimming off
the froth so that the jar contents are actually jam, and not froth.
The process is full of uncontrolled assumptions, and it's very tempting
to take shortcuts like pulling all the jars out of the water and letting
them sit for 10 minutes (cooling off, nasturally ) while you manipulated
the jam (which was also cooling off, of course) It's also tempting to
reuse rubber gaskets from year to year, which would of course crack
and become all hard, rather than buying new ones.
The rings + glass lids + gaskets were an improvement, as what
you did was you poured in the jam, screwed the lid down lightly,
then processed it in a BWB canner, then when done you pulled
out the jar and tightened the ring down. You also used a headspace,
same as you do with the 2 piece lids. However since the lid is
glass, there's none of this dimpling down or up on the lid nonsense to
indicate if the seal was good or not. Instead, you just stored the
jam away and checked it in a month and if the headspace wasn't full
of mold, you assume you have a good seal.
The thing is, to me both processes are rediculous. The 2 piece lid
design is simply a better design. With the cost of time to get the
fruit, time to make the jam, time to cook it down, not to mention
the raw cost of the sugar and energy to heat the jam, why on earth
would you want to fool with a canning method that if you lose seal
on a jar, the only way your going to know is if the contents rot a
month or so later, when you can't do anything about it.
If a 2 piece lid fails to seal, your going to know about it within a
few minutes of pulling it out of the BWB canner, whereupon you
can merely retighten the lid or replace the lid and reprocess the
jar right then, when the canner's at full boil. You don't lose the
contents at all.
Ted