In a large bowl, add the peeled, pitted and finely diced peaches, sugar, finely diced jalapeno peppers, and the lemon juice and zest. Stir to mix, cover with plastic wrap and allow to sit for 1 hour to macerate the peaches and dissolve the sugar.

In a large pot over medium heat, add the macerated peaches and all of the juices, bring to a gentle boil, stirring frequently to prevent catching on the bottom of the pan. Cook for about 20 - 30 minutes, skimming off the foam that forms on top. Test the jam by dropping a small spoonful of jam onto a cold plate, if a skin forms after about a minute, then the jam is ready, otherwise, continue to cook for an additional 5 - 10 minutes and test again.

Once the jam has reached setting point, use a funnel to pour the hot jam into cleaned, dry glass jars, remember to leave about 1/4 inch space at the top. Screw on lids and bands, do not fully tighten, then process in a hot water bath for 10 minutes.