Blanch peaches. Fill 2/3 of a large soup pot with water. Bring to a boil. Add peaches for 30-45 seconds, then remove with slotted spoon and transfer immediately to a large bowl of cold water.
Peel the skin, cut the peaches into quarters and remove pits.
Place all peeled peaches in a large soup pot and squeeze in juice of 1 lemon. Drizzle well with 2 cups sugar, toss and drizzle again with the remaining 1.5-2 cups so the sugar reaches all the peaches.
Let peaches sit at room temp with the sugar for about 30min-1 hour, or until sugar is dissolved.
Place the pot over the stove uncovered and bring to a light boil, stirring to prevent scorching. Once the whole pot is at a light boil, simmer for 10 minutes and turn off the heat. Let the pot stand uncovered until it is just warm to the touch or reaches room temp.
As soon as it cools, repeat step 3. You will bring it to a light boil a total of 5 times, but the time between is up to you. Preserves have plenty of sugar, so they won’t spoil at room temp if you leave it on the counter overnight. If you want the preserves to have an even thicker consistency, you can boil it 6 times.
The last time you bring it to a boil you will want to transfer it to sterilized jars while it’s boiling hot.
Sterilize + Store
Wash jars and let them dry in the oven at 215 for about 20 min or until completely dry. Boil the lids 5 min.
Transfer your boiling hot preserves to the jars using a glass measuring cup, leaving about 1/2″ space.
Screw the lids on enough to keep a tight seal in place, but don’t over-tighten them since air bubbles need to be able to escape.
Place packed cans into the canning pot and cover with 1-2 inches of water. Bring to a boil and process 15 minutes. Remove from the pot with a jar lifter and leave at room temperature undisturbed for 12-24 hours. You may hear a pop when the jars fully seal.
After 24 hours, check that the seal has formed by pushing down on the center of the lid—it should not move at all. If the seal does not form, refrigerate preserves and enjoy within 3 months.