We made and canned this jam in May, which is just about the height of Bay Area jam season. It’s a relatively low-sugar jam using a full tray of strawberries (6 ventilated pint containers, about ~4.5 lbs) and Pomona’s pectin.
- ‘Hull’ strawberries. That is: using a paring knife remove the green, leafy top and the pale white flesh immediately underneath.
- Add strawberries to a non-reactive pot, heat gently and then mash.
- Add to pot and stir until incorporated:
- 2 cups sugar
- 4 tsp Pomona’s pectin
- 4 tsp Calcium water (prepped from Pomona’s pectin instructions)
- Bring to a full rolling boil and then add:
- vinegar (we used about 1/3 cup of sherry vinegar)
- salt (to taste, 1 teaspoon)
- Cook at high heat until frothing subsides and the top is glossy, about 10 minutes.
- Check that the jam has ‘set’ by cooling some on a plate. It shouldn’t move much when cooled.
- You can vary the amount and type of sugar, salt, and acid to your own preference.
- If canning, this amount fills about up about 4-5 pint Ball jars.