First, blanch your peaches to remove the skins.

1. Put your peaches into a pot of boiling water, for 1 minute. No longer.
2. Then remove from the boiling water, and immediately put them into a cold water bath, for 1 minute. No longer. Do not soak them.
3. The skins should just peel off.
4. Peel off the skins.

Making the Jam

1. Then remove the pits, and slice up the peaches.
2. Place peach slices, lemon zest and lemon juice into a heavy bottomed large pot, over medium-low heat.
3. Cook for about 15 minutes, until the peaches are soft, and the juices are released.
4. As the peaches soften, stir frequently, and use your spoon or a potato masher to break them down.
5. At this point, add your sugar, and stir until dissolved.
6. On medium-high heat, bring the mixture to a boil, cook for 5 minutes, stirring continuously.
7. After the 5 minutes, reduce the heat to low-medium (don’t boil the jam, just slow cooking), for another 40-60 minutes. You will know that the jam is ready when the mixture is thick enough to leave a trail behind the spoon (a little trick from Martha Stewart). NOTE: the jam will also thicken as it cools, so be careful not to overcook it.
8. Remove from heat, and let cool completely before serving.