Jam (recipe)

1. Before you begin, place a small plate in the freezer to use for testing the set, and sterilise two clean jars and their lids by washing in hot soapy water and drying in a low oven.
2. Crush the hulled strawberries in a wide heavy-bottomed pan with a potato masher, leaving a few small chunks for texture, then stir in the lemon juice and the pectin until evenly combined.
3. Bring the fruit to a full rolling boil over high heat that cannot be stirred down, then add all the sugar at once and stir constantly until it has completely dissolved.
4. Return the jam to a hard boil and cook for about 4 minutes, stirring frequently to prevent catching, then add the knob of butter, which helps disperse any foam on the surface.
5. Test the set by spooning a little jam onto the chilled plate and pushing it with a fingertip after 30 seconds; it is ready when the surface wrinkles, otherwise boil for another minute or two and test again.
6. Remove from the heat, let the jam stand for 5 minutes so the fruit suspends evenly, then ladle into the warm sterilised jars, seal immediately, and leave to cool fully before storing in a cool dark place or the refrigerator once opened.

You'll use: Oven · Pan · Large pot · Saucepan