jar of plum marrow and fennel jam spread on slice of bread

Ben Cooper's September Plum, Marrow and Fennel Jam

What to eat in September

Aubergine, Beetroot, Blackberries, Broccoli, Brussels Sprouts, Butternut Squash, Carrots, Cauliflower, Celery, Courgettes, Chicory, Chillies, Cucumber, Damsons, Garlic, Kale, Kohlrabi, Leeks, Lettuce, Mangetout, Marrow, Onions, Parsnips, Pears, Peas, Peppers, Plums, Potatoes, Pumpkin, Radishes, Raspberries, Rhubarb, Rocket, Runner Beans, Samphire, Sorrel, Spinach, Spring Greens, Spring Onions, Strawberries, Summer Squash, Sweetcorn, Swiss Chard, Tomatoes, Turnips, Watercress, Wild Mushrooms


Plum, Marrow and Fennel Jam

 Makes approximately 1.5kg of Jam


  • 350g marrow flesh - peeled, de-seeded and roughly chopped 
  • 550g red plums - quartered and stones removed
  • 100g fennel thinly sliced
  • 60ml water
  • 1kg jam sugar / preserving sugar 


  1. Put 2 or 3 small saucers in the freezer; they'll be used to quickly cool teaspoons of jam to find when the setting point has been reached.

  2. Place your washed, rinsed and dry jars and lids on a baking tray and heat in the oven at its lowest setting.Turn off the oven when the jars are hot, but leave them inside until you're ready to pot the finished jam.

  3. In a large, wide pan put the marrow and plums on a medium heat and add the water and gently cook until both are very soft (approx 30 min). Stir occasionally to prevent sticking or burning.

  4. Take off the heat and carefully with a potato masher, mash the contents of the pan to break down the roughly chopped plums and marrow.

  5. Add the sugar and mix, then put the pan back on the heat.

  6. Turn up the heat and bring the contents to a boil – you can put a lid on for this stage to speed it up.

  7. As soon as the jam has come to the boil, take the lid off and keep at a rolling boil until setting point is reached (15 - 30 min). Add the fennel and cook for a further 10 minutes.

  8. To test for setting point:                                                                          Take the saucepan off the heat.                                                              The Flake test: Take some jam on a wooden spoon, cool it a little, then let it fall off the edge of the spoon. If the final bits of jam come together into 'flakes' rather than running off in a stream then proceed to the Saucer test. If it doesn't flake, boil for another 4-5min then test again.
    The Saucer test: Take one of the cold saucers from the freezer, put a teaspoon of jam on it to cool then gently push the jam with your finger. If it wrinkles the setting point has been reached. If not, boil for another 4-5 min then test again.

  9. Once the setting point has been reached. Protect your hands, take the jars from the oven and decant the jam into them. Put the lids on and leave to cool.

  10. When the jars are cold, tighten the lids a little more if possible. Label and store in a cool, dark place.

The jam will be ready to use immediately, but unopened jars should last at least a year.

N.B The flavour and appearance of the jam will depend on the variety of plums you use.

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