If using fresh peaches, give them a wash and remove the pits. You can leave the skins on if you are going to blend them smooth, or peel them if you prefer a more uniform texture. Chop peaches or measure out peach pulp.
Add peaches, lemon juice, and sweetener (if desired) to a blender or food processor. Blend until smooth.
Place the puree into a saucepan and simmer for two to three minutes over medium low heat.
Line your trays with silicone mats or parchment paper. Use a spatula to spread the peach puree evenly onto the tray. Keep the layer about one-eighth of an inch thick, avoiding thin, tapered edges.
In a dehydrator, dry at 135 degrees Fahrenheit for about six to eight hours. In the oven, bake at the lowest setting, usually around 170 degrees, for five to six hours or until dried. The leather is done when it feels dry to the touch and peels away easily from the mat or paper. Let the leather cool completely.
Use scissors or a knife to cut it into strips. Roll them in parchment paper and store in an airtight container.
Notes
Spread the puree evenly to help it dry consistently and avoid sticky or brittle spots.
Use silicone mats or parchment paper for easier clean-up.
Taste your puree before drying. If the peaches are too tart, stir in a small amount of honey or sugar.
Store finished leather at room temperature in a sealed container for up to one month. For longer storage, freeze it.