Stephen Williams wrote:

: One other tip you may wish to use is to cap the Jelly with a wax coating
: after it has set in the Jar.

I beg to differ. pour the very hot jelly into heated jars and screw down
the lids firmly immediately to make an air tight seal. As the they cool
down, the lids should "pop" as a vacuum forms inside. Thus treated they
should keep for years - literally.

I'm baffled by this allowing to cool in the open and then waxing business.
Invariably there is contamination and the jam/jelly is less likely to keep
very long.

Only thing I can think of is that it is advice from the period before
glass jars and air tight tops were available. Also I suppose they look
pretty in glossy photos in coffe table preserve books.