—Allow steam to escape from open petcock or weighted gage opening for at least 10 minutes to drive all air from canner. Then close petcock or put on weighted gage.
—When pressure reaches 10 pounds (240° F), start counting processing time. Keep pressure constant by regulating heat under the canner.
—When processing time is completed, remove the canner from heat immediately. Cool undisturbed at room temperature until the pressure registers zero. After a minute or two, slowly open the petcock or remove the weighted gage. Unfasten the cover and tilt the far side up so steam escapes away from you.
—Remove containers from canner with jar tongs.
—Adjust lids if necessary.
—Cool jars on a rack or folded towel away from drafts.
Cooling snap beans on a rack. Leave space between jars so air can circulate.
Day-After Check
Jars should be examined after they have cooled, but within 24 hours after processing, to be sure a seal has been obtained. To test a jar that has a flat metal lid, press the center of the lid; if the lid is down and will not move, it is sealed. Turn jars with porcelain-lined zinc caps partly over in your hands; if they do not leak, they are sealed.