Blackberry jam

It’s blackberry season in the UK, so I seem to return from almost every woofer walk clutching a bag full of juicy ripe fruit and sticky fingers. Even The Teen enjoys a spot of blackberry picking which has meant that we’ve had some lovely long walks together, followed by me bubbling up a jammy storm in the kitchen. Making jam is really simple, but having the right bits of kit really help – a sugar thermometer that helpfully has a jam temperature marker takes out all of the guesswork so I’d highly recommend that, plus a stash of jam jars of course! Makes 4 – 5 standard jam jars full, but if you run out of jars then just keep the overflow in the fridge in whatever receptacle you have and munch away. Also if, like me, you find that you can’t pick an exact kilo of fruit, then just scale up or down the measurements accordingly (I had 660g of fruit and made 3 jars).


1kg blackberries

1kg caster sugar, either

  1. the kind with pectin already included, or
  2. plus 8g pectin powder

The juice of 1 lemon

4 or 5 jam jars (sterilised, see below)

Wax circle discs


  1. The night before you want to make the jam, rinse the blackberries and put them in a large bowl. Add in the sugar and pectin (if you’re using separate pectin), stir gently, then cover and leave overnight or up to 24 hours to let the sugar start dissolving and break down the fruit a little.
  2. When you’re ready to make the jam, sterilise your empty jars – see the note below.
  3. While the jars are in the oven, tip all of the fruit, sugar and pectin into a large saucepan, add in the lemon juice and bring the whole lot to the boil.
  4. Pop in your sugar thermometer, and wait for it to reach the jam marker (104-105C) – it’ll take around 10 minutes.
  5. When the magic temperature is reached, turn off the heat and leave it to cool for 15 minutes or so.
  6. Tip the jam into a jug for easier pouring, then fill each jar up to a cm or so before the rim, pop on a wax disc (wax side down), screw on the lid, and allow to cool completely.
  7. Your jam is now ready to use and unopened jars will keep for months and months in theory (it never lasts that long in our house before being eaten up!).

How to sterilise jars:

  1. Heat oven to 160C, and while waiting wash your empty jam jars and lids in hot soapy water.
  2. Rinse each jar/lid and place them upside down on a baking tray while still wet.
  3. Pop the tray into the oven for 15 minutes, et voilà! you’ve got sterilised jars.

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