Step 1
Mash 10 lb. peaches, sliced, and their pits in a large, nonreactive pot, using your hands, until no large pieces of fruit remain. For every quart of fruit pulp, add 1 cup water; bring to a boil over high heat. Decrease the heat to low, and simmer until very juicy, about 20 minutes.
Step 2
Place the fruit in a jelly bag and place over a large bowl. Let rest until all the liquid has drained, about 6 hours or overnight.
Step 3
When you are ready to make the jelly, place a wire rack on a rimmed baking sheet. Place several small plates in the freezer to use later to test the consistency of the jelly. Sterilize four ½-pint canning jars and lids in boiling water, following the manufacturer’s instructions. Remove hot jars from the water and place upside down to drain on the prepared rack. Remove the lids from the water and dry with a clean towel. Turn the sterilized jars right side up on the rack, using tongs or a kitchen towel to protect your hands. When they are cool enough to handle, dry them with a clean towel. Set aside.
Step 4
Measure the amount of peach juice (you should have about 8 cups) and place it in a large nonreactive pot. Discard pulp. For every cup of peach juice, add ¾ cup sugar. Add the juice of ½ lemon.
Step 5
Bring peach juice mixture to a rolling boil. Skim foam as it collects on the sides of the pot. Continue cooking until mixture reaches the jelling point, 220°F on an instant read or candy thermometer. (To test the jelly without a thermometer, dribble a few drops of hot jelly on one of the frozen plates; if the jelly is ready, it will crinkle on the plate when you push it with your finger. If it doesn’t crinkle, continue to boil the jelly for another 5 minutes and test again.)
Step 6
Remove jelly from the heat. For each jar, insert a canning funnel and carefully ladle jelly into jar, allowing at least ¼” headspace between the surface of the jelly and the top of the jar. Clean the rims of the jars with a clean, damp towel, and tightly secure the lids.
Step 7
Set up a water bath canner with a large deep pot and canning rack; fill with enough water to cover the jars by at least 1″ and place jars on the rack. Cover the canner and bring water to a boil. Simmer gently for 5 minutes. Using canning tongs, transfer jars to a towel to cool. If the seal works and fits properly, the metal lid will be slightly concave within 24 hours of processing.
Do Ahead: Store unopened jars of jelly at room temperature for up to 1 year. Once the jar is opened, store in the refrigerator for up to 1 month.
Photo by Travis Rainey, Food Styling by Liberty Fennell
Variation: For refrigerator or freezer jam, transfer hot jelly to sterilized freezer-safe plastic containers or freezer-safe jars with lids, leaving 1″ of headroom. Let cool, then freeze for up to 1 year or refrigerate for up to 1 month.
Editor’s note: This peach jelly recipe was first printed on Epicurious in December 2011.