Note: Flat-bottomed canners are
required for glass cooktops.
When canning with water-bath or
pressure canner, larger-diameter pots
may be used. This is because boiling
water temperatures (even under
pressure) are not harmful to the cooktop
surfaces surrounding the surface
elements.
HOWEVER, DO NOT USE LARGE-
DIAMETER CANNERS OR OTHER LARGE-
DIAMETER POTS FOR FRYING OR BOILING
FOODS OTHER THAN WATER. Most syrup
or sauce mixtures—and all types of
frying—cook at temperatures much
higher than boiling water. Such
temperatures could eventually harm
the glass cooktop surfaces.
Be sure the canner fits over the
center of the surface element.
If your cooktop or its location does
not allow the canner to be
centered on the surface element,
use smaller-diameter pots for good
canning results.
Flat-bottomed canners must be
used. Do not use canners with
flanged or rippled bottoms (often
found in enamelware) because
they don’t make enough contact
with the surface elements and take
a long time to boil water.
When canning, use recipes
and procedures from reputable
sources. Reliable recipes and
procedures are available from
the manufacturer of your canner;
manufacturers of glass jars for
canning, such as Ball and Kerr
brand; and the United States
Department of Agriculture
Extension Service.
Remember that canning is a
process that generates large
amounts of steam. To avoid burns
from steam or heat, be careful
when canning.
NOTE: If your house has low voltage,
canning may take longer than expected,
even though directions have been
carefully followed. The process
time will be shortened by:
(1) using a pressure canner, and
(2) starting with HOT tap water for
fastest heating of large quantities
of water.
CAUTION:
■Safe canning requires that harmful
microorganisms are destroyed and
that the jars are sealed completely.
When canning foods in a water-bath
canner, a gentle but steady boil must
be maintained for the required time.
When canning foods in a pressure
canner, the pressure must be
maintained for the required time.
■After you have adjusted the controls,
it is very important to make sure the
prescribed boil or pressure levels are
maintained for the required time.
■Since you must make sure to
process the canning jars for the
prescribed time, with no interruption
in processing time, do not can on any
cooktop surface element if your
canner is not flat.