Wash, peel, and chop the peaches into small pieces. Remove all pits and keep the pieces slightly uneven for better texture.
Add the chopped peaches to a large pot. Cook on medium heat, stirring every few minutes until the peaches release juice and become soft.
Add sugar and lemon juice to the pot. Stir continuously until the sugar fully dissolves into the fruit mixture.
Gently mash the peaches while cooking. Leave small chunks for texture. Continue to simmer the mixture, stirring often, until it thickens.
Watch the jam closely as it cooks. Stir more often near the end to prevent sticking or burning.
Test the jam by placing a small amount on a cold plate. If it thickens and holds shape, it is ready. If not, cook for a few more minutes and test again.
Remove from heat and let it cool slightly. Pour into clean jars and allow to cool completely before sealing. Store in the fridge.