4 cups peeled, pitted and crushed yellow peaches (3 1/2 to 4 pounds)
1/4 cup strained fresh lemon juice
7 1/2 cups sugar
1/2 teaspoon unsalted butter
1 (3 ounce) pouch liquid pectin
In an 8 quart pan, combine the peaches and lemon juice. Stir in about half the sugar. Cover the pan and let stand for 20 minutes.
Remove the cover. Stir in the remaining sugar and the butter. Over medium-low heat, stirring constantly, heat the mixture until the sugar is completely dissolved. Increase the heat to medium-high, and bring the mixture to a full rolling boil, stirring constantly. Boil, stirring constantly for 1 minute. Remove the pan from the heat. Skim off any foam.
Return to the pan to the heat and bring the mixture to a full rolling boil. stir in the entire contents of the pectin pouch. Return the mixture to a full rolling boil, stirring constantly. Boil, stirring constantly, for 1 minute. Remove the pan form the heat. Skim off any foam.
To prevent the jam from separating in the jars, allow the jam to cool 5 minutes before filling the jars. Gently stir the jam every minute or so to distribute the fruit. Ladle the hot jam into hot jars, leaving 1/4-inch headspace. Wipe the jar rims and threads with a clean, damp cloth. Cover with hot lids and apply screw rings. Process half-pint jars in a 200 degree F (93 C) water bath for 10 minutes, pint jars 15 minutes.