Do you have an excess amount of freshly picked Blackberries? Or have you seen them overflowing on the shelves at your local green grocer and picked up a couple of punnets? Then, turn these plump, juicy blackberries into a jar of deliciously Easy Blackberry Jam.
One of the best parts of the end of summer is the abundance of these little fruit jewels that grow so avidly at this time of year. I had one of my close friends ask what to do with her glut of blackberries and along with crumble, hand pies, tart or scones ... my answer is a resounding yes for jam.
I live in central London. Yes there are pockets of areas where blackberries grow in the city but realistically - sourcing them in this way isn’t convenient on a frequent basis. I go to my local fruit and veg stall holder on the high street and buy them from there. My point is that wherever you get them, it doesn’t matter, jam can always be made!
I also want to dispel the myth that you need buckets full of blackberries to make jam. You don’t. I bought two punnets totalling 400g and they made two jars worth and it only took 20 minutes. You could put the kettle on and by the time you’ve drunken your tea you’ve made your jam. Blackberry jam is super simple to make. There I said it.
What goes into jam?
There are a variety of ways to make jam but I find that the only ingredients needed are:
- the blackberries themselves - the hero of the moment
- sugar - to sweeten it all up and act as a preservative
- lemon - to cut through that sweetness
- and a small amount of cornstarch - to help thicken the jam slightly
How to make jam
In a medium saucepan add all your ingredients and over medium heat bring the fruit to a boil.
Stirring frequently, allow the fruit to boil for 20 minutes until the fruit starts to thicken. At this point the jam is ready to set but see below for some fool proof ways on checking if you have reached the setting stage.
How to tell if your Easy Blackberry Jam is set
There are a couple of ways to check that your Blackberry Jam has set:
- Use a sugar thermometer and once the temperature of the fruit reaches 105C your ready to jar it.
- Use the frozen plate method. Before you start making your jam, place a couple of small plates in your freezer. After 15-20 mins when you think the jam is ready then remove a plate from the freezer and dollop a small amount in the centre. Leave it for a minute and then run your finger through the centre of the dollop. If it wrinkles and when separated, doesn’t run together then it’s ready to bottle.
- The drip method. After the 15-20 minutes of cooking you’ll notice that the jam has started to thicken. Dip your spoon into the jam and when lifting it out then turn it onto it’s side. If the jam takes a while to form a long slow drip then it has reached it’s setting point
If the jam isn't ready then return the saucepan to the heat and cook for a further 5 minutes and then test again.
Once setting point has been reached then remove the pan from the heat, scoop any scum off the top and ladle immediately into sterile jars. Leave 2 cm room from the top and seal with a screw top lid. Jam will thicken as it cools.
For further information on how to sterilise your jars you can check out this article from The Spruce Eats.
I’m a massive fan of blackberries so you can find other blackberry recipes here:
Earl Grey Cupcake with Blackberry Curd Filling. Recipe found here
Chocolate Sour Cream cake with Blackberries. Recipe found here.
Easy Blackberry Jam
- 400 g fresh blackberries
- 300 g granulated sugar
- 1 lemon, juice
- 1 teaspoon cornflour (corn starch)
- In a medium saucepan add all your ingredients and over medium heat bring the fruit to a boil.
- Stirring frequently, allow the fruit to boil for 20 minutes until the fruit starts to thicken. Remove from the heat and place a small dollop on a cold saucer. Push your finger through the dollop and if it feels gel-like and wrinkles then the jam has reached setting point. If it isn’t ready then return the pan to the heat and boil for another five minutes before testing again.
- Ladle immediately into sterilised jars leaving 2 cm from the top and seal immediately with a screw top lid
All recipes are developed and tested in Metric grams. I strongly recommend that you bake using digital scales for a more accurate result. I have provided a conversion to US customary in the recipe but please note that I haven’t tested using this method.