After you’ve pitted the cherries (I recommend listening to Gillian Welch or the Alison Krauss Pandora station while doing this), place them in a large bowl with the lemon juice and sugar, if using. Let stand about 10 minutes.

In a large heavy saucepan, place the cherries, lemon juice, and sugar and bring to a boil. Lower to a simmer and cook until cherries are thoroughly cooked and the jam begins to thicken. This may take up to 20-30 minutes.

Remove from heat and pour into sterilized jam jars and either seal/can or bring to room temperature and then store in the fridge. Jam should last up to 2 weeks if not canned and up to one year if canned.