Adjust Caps

Almost every recipe for jam seems to use the term "adjust caps" before processing in a boiling-water bath. What does "adjust caps" mean? —M.G., Lompoc, California

Recipes that use the term "adjust caps" or lids are referring to sealing the filled canning jars with metal lids and screw bands. To properly adjust lids, wipe the jar rims with a clean dampened dishcloth or paper towel. Place lids on jar rims with the gasket side down next to the glass. Screw metal bands evenly and firmly over lids just until resistance is met. Then process the jars according to the recipe directions.