Wash, peel, and slice the peaches. Blanching in boiling water for 30 seconds, then ice water, makes peeling easier. Slice into 1/2-inch pieces.

In a large saucepan, combine peaches, sugar, and lemon juice. Stir well.

Stir in the liquid pectin. Bring to a full rolling boil over high heat, stirring constantly.

Boil hard for exactly 1 minute, stirring constantly.

Remove from heat; skim off any foam. Ladle hot jam into sterilized half-pint jars, leaving 1/4-inch headspace.

Wipe jar rims clean. Place lids and rings on jars; tighten fingertip tight. Process in a boiling water bath for 10 minutes (adjust for altitude).

Cool completely. Check seals. Store sealed jars in a cool, dark, dry place. Refrigerate unprocessed jam and use within 2-3 weeks.