can be more frustrating when canning food than finding you do not have
enough liquid left in your jars to cover the food. This is one of the
most common problems canners experience says Janie Burney, a professor
and food preservation specialist with the University of Tennessee
Extension Department of Family and Consumer Sciences.
In a few short questions and answers, Burney explored the answer to this and other related questions.
Question: Why do I lose liquid from my canned green beans when I process them?
could have to do with the change in pressure. When you remove the lid
of the pressure canner and there is still pressure inside the canner and
jars, the change in pressure can force liquid out of your jars. Make
sure you allow enough time for your canner to depressurize, but don’t
try to force it. Forcing a canner to depressurize by placing it in a
draft, on an air conditioning vent, or in cold water leads to loss of
liquid from jars and may result in unsafe food or food spoilage. Forcing
a canner to cool to quickly also can cause it to warp and not maintain
Question: How long does it take for a canner to depressurize?
depends on the canner. Standard-size heavy-walled canners require about
30 minutes when loaded with pints and 45 minutes when loaded with
quarts. If you have an older canner that is heavy and does not have a
dial gauge to determine when the pressure drops, use a timer. Newer,
thin-walled canners cool more rapidly and have vent locks. Vent locks
have a piston that drops to a normal position when the canner is
Question: How soon after it depressurizes should I remove the weight from the vent port or open the petcock.
ten minutes after the canner has depressurized. Remove the weight or
open the petcock. Unfasten the lid and remove it carefully so that steam
does not burn your face or hands.
Question: I allow my canner to depressurize correctly, but I still lose liquid. What is causing this?
pressure may be fluctuating during processing. Closely watch the canner
during processing to maintain a steady pressure at or slightly above
the correct gauge pressure. If your canner has a weighted gauge rather
than a dial gauge, follow the manufacturer’s directions for how the
weighted gauge should move and how often it should jiggle or rock.
pay attention to how you pack your jars when using a pressure canner or
water-bath canner. Work the air bubbles from jars before processing
them by running a plastic spatula between the food and the jar. Avoid
over packing the jars because food packed too tightly in jars can boil
over during processing and start a siphon.
sure you have enough liquid to fill in around the solid food in the jar
and cover the food. It takes from ½ to 1 ½ cups of liquid for a quart
Question: What happens if I lose liquid from my jars? Is it safe to eat?
If you lose liquid from your jars, do not replace the liquid. Loss of
liquid does not cause food to spoil. However, the food above the liquid
may darken. If the loss is excessive (if at least half of the liquid is
lost), refrigerate the jars and use within 2 to 3 days.
For more information about home canning and food preservation, contact your local county UT Extension Office.
Extension provides a gateway to the University of Tennessee as the
outreach unit of the Institute of Agriculture. With an office in every
Tennessee county, UT Extension delivers educational programs and
research-based information to citizens throughout the state. In
cooperation with Tennessee State University, UT Extension works with
farmers, families, youth and communities to improve lives by addressing
problems and issues at the local, state and national levels.
Dr. Janie Burney, Department of Family and Consumer Sciences, 865-974-7402, firstname.lastname@example.org