"Melba's Jammin'" provided the Certo directives:

<snip>

> Followed by:
> "Note: While you can still use the USDA boiling water bath method of
> preparing jams and jellies, CERTO has eliminated the need for this step.
> Because jams and jellies are high acid foods, jar preparation can be
> made simpler by starting with clean jars and working through the recipe
> without delay. Contaminants in jars are destroyed when hot fruit
> mixtures are poured *immediately, jars covered and inverted. (When
> preserving *all other foods*, follow recommended USDA water bath or
> pressure-canning methods.

"High acid" alone be damned! The purpose of the water bath is to reach
higher temperatures and hold them for a longer period of time than inversion
can achieve.

It's true enough that the temperature of jelly/jam when it's poured is
probably enough to kill off simpler bacteria, but in no way is it enough to
penetrate and kill a spore (a strain of bacillus that has formed a nasty
nearly indestructable "shell"). Steam under high pressure produces enough
heat to do in spores (as is produced in a pressure canner used for "low
acid" foods), so does sustained high temperature in a covered water bath
canner, but the inversion method doesn't hold temperature high enough long
enough to do the deed.

The acid environment matters inasmuch as creepies don't like any pH that
varies much from neutral and an acidic environment is natural and
complementary to food, but even acidic foods that are to be *stored* must be
processed to attempt complete kill and seal the deal.


> Their jar prep instructions advise: "Wash jars and screw bands in hot,
> soapy water; rinse with warm water. Pour boiling water over flat lids
> in saucepan off the heat. Let stand in hot water until ready to use."

That will give them a basic cleaning: removing substances used in
manufacture and other surface contaminants. But it does nothing to produce
an aseptic condition, nor does it promote one as mishandling of very hot
equipment encourages recontamination through fumbling and dropping. Boiling
water can damage the sealing compound on the lids, and "let stand in hot
water until ready to use" doesn't mean anything by itself. How hot is "hot"?
Scalding hot? Comfortably hot? Not cold hot? The list goes on. Further, how
long does "hot" stay that way?

<blush!> Sorry about the lecture.