Description
A classic homemade blackberry jam made with a mix of summer berries, lemon juice, and jam sugar containing pectin. This easy-to-follow recipe allows the fruit and sugar to macerate overnight for faster cooking and a perfect set. The jam is cooked on the stovetop and fluffed with a knob of butter to reduce scum, resulting in a rich, flavorful preserve that can be stored for months in sterilized jars.
Ingredients
Scale
Berries and Sugar
- 1.8 kg mixed summer berries (hulled strawberries – large ones halved, raspberries, redcurrants, blackcurrants, and early blackberries)
- 1½ kg jam sugar (with added pectin)
Additional Ingredients
- Juice and pips of 1 lemon
- Finger-tip size knob of butter (optional)
Instructions
- Macerate the Fruit: The night before making the jam, layer the mixed berries and jam sugar in a very large bowl. Cover and let sit at room temperature overnight to allow the sugar to dissolve and the fruit to release its juices, reducing cooking time the next day.
- Prepare for Cooking: In the morning, stir the mixture gently and leave aside until ready. Place a small saucer in the freezer to chill for later testing the jam’s set.
- Start Cooking the Jam: Transfer the berry and sugar mixture with all juices into a preserving pan or large wide-based pan. Stir in the lemon juice. Collect the lemon pips, place them in a tea strainer or muslin cloth, and add it to the pan to help extract natural pectin during cooking.
- Dissolve Sugar and Boil: Heat the pan over low heat, stirring occasionally, until the sugar is fully dissolved. Then increase the heat and bring the fruit mixture to a rolling boil. Simmer for 5 minutes.
- Test Setting Point: Turn off the heat and spoon a little hot jam syrup onto the chilled saucer. Allow it to cool, then push it with your finger. If it wrinkles slightly, the jam has set; if it remains runny, return the pan to boil for 2-3 minute intervals, testing after each until the jam wrinkles when pushed.
- Remove Scum and Finish: Skim off any excess scum from the top of the jam. Optionally, stir in a knob of butter to dissolve remaining scum and clarify the jam.
- Rest and Jar the Jam: Allow the jam to rest for 15 minutes so the fruit settles evenly. Then ladle the hot jam into sterilized warm jars. Seal jars with lids or wax discs and label with the date. Store in a cool, dark place for up to 6 months. Refrigerate after opening.
Notes
- Use wide-based preserving pans to speed up evaporation and reduce cooking time.
- Always sterilize jars by washing and heating them in a 170°C oven for at least 10 minutes before filling.
- The lemon pips are important for natural pectin, ensure to tie them in muslin or use a tea strainer to avoid pips in the jam.
- Butter is optional but helps to reduce scum and improve jam clarity.
- Test for jam set using a chilled saucer and finger wrinkle test to avoid over or under cooking.
- Variants include raspberry & rose jam (with rosewater instead of lemon), zingy blackcurrant jam (with cassis), and strawberry & vanilla jam (with vanilla pod seeds).
- Label jars with date and contents for easy identification and gifting.
- Prep Time: 12 hours (overnight maceration)
- Cook Time: 20 minutes
- Category: Preserves
- Method: Stovetop
- Cuisine: British
Keywords: blackberry jam, mixed berry jam, homemade jam, preserving, stovetop jam, fruit preserves, summer berries jam
