Easy Blackberry Lemon Jam Recipe

Instructions:

1. Place the cleaned blackberries in a heavy-bottomed pot. Using a wooden spoon or potato masher, gently crush about half of the berries to release juices.
2. Add the granulated white sugar and fresh lemon juice to the pot. Place over very low heat and stir constantly with a wooden spoon until the sugar has completely dissolved into the berries, ensuring the mixture does not boil.
3. Increase the heat to medium-high and bring the mixture to a full rolling boil. Stir vigorously and constantly. If excessive foaming occurs, stir in the unsalted butter to break the surface tension.
4. After 20–25 minutes of boiling, test for the set. Perform the Sheeting Test by dipping a wooden spoon into the jam; it should fall in a slow, thick sheet. Alternatively, perform the Plate Test by dropping a spoonful of jam onto a chilled plate and checking if it wrinkles when pushed.