Combine all, bring to a boil. Simmer and let reduce by at least half, stirring regularly to prevent the pot from scalding. Puree the mixture a little with an immersion blender; you still want it to be a bit chunky. Continue simmering until it reduces by half again and becomes a sticky jammy mess. When jam has cooked down sufficiently, remove pot from heat and ladle into hot, sterile half-pint jars leaving 1/4 inch headspace. Wipe rims, apply lids and bands and process in a boiling water bath for 25 minutes.