Prep the peaches - Wash, peel, and pit your peaches. Slice into chunks. The riper they are the sweeter your butter will be.
Soften the fruit - Add peaches and slash of water to a large pot. Simmer on medium heat until very soft and juicy, about 10 to 15 minutes. Stir now and then so nothing sticks.
Puree until smooth- Puree with an immersion blender (or carefully in a regular blender).
Sweeten and brighten- Stir in sugar to taste and lemon juice, plus cinnamon or nutmeg if you like. I actually used a couple cinnamon sticks and some star anise for flavor as it simmered.
Slow simmer - Reduce heat to low and cook uncovered, stirring often, until thick and silky. You'll know it is ready when a spoon dragged across the bottom leaves a brief track and the puree fall in thick ribbons.
Set up canner and jars - While the butter simmers, place a rack in your water bath canner, fill with enough water to cover jars by 1 to 2 inches, and bring it to a simmer. Wash jars, lids, and bands. Keep jars hot until filling. Tip: If your final processing time is 10 minutes or more, pre-sterilizing jars isn't required, but they need to be clean and hot.
Fill the jars - Ladle hot peach butter into hot half-pint or pint jars leaving 1/4 inch headspace. Remove air bubbles, adjust headspace, wipe rims clean, place lids on, and screw bands on fingertip tight.
Process in a boiling water bath - Lower jars into water bath canner so they are covered by at least an inch of water. Bring back to a steady boil and process for 10 minutes.
Cool and check seals - Turn off heat, rest 5 minutes, then lift jars out to a towel. Let cool 12 to 24 hours. Lids should be concave and not flex when pressed. Remove band, wipe jars, label, and store in a cool, dark spot for up to a year.
Storage if not canning - Refrigerate peach butter for up to 3 weeks or freeze for about 6 months. Leave headspace if freezing.
