Combine 1 cup water and 3 cups of peaches in a heavy-bottomed pot.
1 cup water, 3 cups sliced peaches
Break up the peaches using a pastry cutter, potato masher, or wooden spoon.
Cook down over medium heat until the peaches are very soft and steaming.
Blend the peaches with an immersion blender, or in a food processor or blender until smooth.
Mix sugar and lemon juice into the blended peaches, cook on low, stirring often for 2 minutes.
1 tsp lemon juice, 1/3 cup sugar
If you're not canning the syrup, simply transfer it to small containers. Refrigerate and use within two weeks, or freeze for six months.
Notes
You can reduce or increase the sugar depending on your preferences and the sweetness of the peaches. I recommend starting with 1/4 cup and tasting as you go.If you cooked the peaches with the skin on and would like to remove the skin from the final syrup, pour the hot syrup after blending through a fine-mesh strainer placed over a mixing bowl. You may need to use a spatula to push it all through.You can thin the syrup with a bit of extra water after adding the sugar if you're looking for a simple syrup consistency.