In a large pot, combine the chopped peaches, sugar, lemon juice, cinnamon, nutmeg, and salt. Stir well to combine.

Cook the mixture over medium heat, stirring occasionally, until the peaches break down and the mixture starts to bubble, about 10-15 minutes.

Reduce the heat to low and continue to cook, stirring frequently, for about 1-2 hours, or until the mixture thickens to a spreadable consistency.

Once thickened, use an immersion blender to puree the mixture until smooth. Alternatively, you can transfer it to a blender in batches.

Pour the hot peach butter into sterilized jars, leaving about 1/4 inch of headspace. Wipe the rims of the jars with a clean cloth to remove any residue.

Seal the jars with lids and process them in a boiling water bath for 10 minutes to ensure they are properly sealed.

Remove the jars from the water bath and let them cool completely on a clean kitchen towel or cooling rack.