How to Make Blackberry Jam with Chef Jesse Burke

There’s something wonderfully simple about homemade blackberry jam: a handful of locally grown berries, a little sugar and lemon, and a few minutes on the hob can produce something that captures the flavour of late summer.

For Junior Sous Chef Jesse Burke of Azure Harbour Bistro, the key is to start with good local fruit. Look for locally grown blackberries, or pick your own away from roads and other areas where the berries may be exposed to traffic or pollution. Blackberries, raspberries and gooseberries are all in season right now, making this a particularly good time to put some of the summer harvest into jars.

Jesse’s Blackberry Jam

Ingredients

• 500g blackberries
• 375g sugar
• Juice of ½ lemon

Method

1. Sterilise the jars

Wash the jars and lids thoroughly. Place the jars in an oven at about 120°C for 15–20 minutes. Keep them warm until you are ready to fill them.

2. Prepare the berries

Gently rinse the blackberries and remove any stalks or leaves.

3. Soften the fruit

Put the blackberries and lemon juice into a large, heavy-based saucepan. Cook gently for 5–10 minutes, crushing the berries as they soften.

4. Add the sugar

Stir in the sugar over a low heat until it has completely dissolved. Try not to let the mixture boil before the sugar has dissolved.

5. Boil the jam

Bring the mixture to a strong rolling boil and cook for approximately 8–12 minutes, stirring occasionally to prevent the jam catching on the bottom of the pan.

6. Test for setting

Place a small spoonful of jam onto a cold plate. Leave it for 30–60 seconds, then push it gently with your finger. If the surface wrinkles and does not immediately run back together, the jam is ready. If it is still too runny, boil for another two minutes and test again.

7. Fill the jars

Remove the pan from the heat, skim off any foam and leave the jam to stand for about five minutes. Carefully ladle the hot jam into the warm, sterilised jars and seal.

Once cooled, the jam will keep for up to a month.

If you’re in a hurry, Jesse has restaurant tricks that can help you achieve a thicker set.

If you’re short on time you can add a small bit of xanthan gum to thicken the jam. It has no effect on the flavour, but it is important to start with a very small amount: too much can make the jam thick and spongy. A hand blender makes it easy to incorporate.

Another option is agar agar, which is commonly used in professional kitchens to create gels. Jesse’s method is to whisk it into the jam, around 10g per litre of jam while it is cooking, making sure the mixture reaches 80°C. Pour it onto a flat tray, refrigerate for around 30 minutes to set, then blitz it until smooth. Using a flat tray rather than jars helps the jam to cool quickly.

For a smoother jam with fewer seeds, pass the finished mixture through a fine strainer. This will also remove any unwanted pith and give the jam a more refined texture.

And for an extra boost of fibre, you can add chia seeds.

Blackberries aren’t the only ingredient worth making the most of right now. Courgettes are a great asset in the kitchen this time of year.

Jesse says courgettes are one of the most versatile vegetables in the kitchen. They can be used in everything from purées and veloutés to risottos. Small Parisian-style courgette balls or twists can be mixed with yellow courgette for a colourful presentation.

One of his particularly useful techniques is to brine courgettes rather than cooking them. A 2% brine for 10–15 minutes helps break down the vegetable’s fibre, making the courgette much more flexible. The softened strips can then be bent or swirled into attractive shapes, an easy way to add a restaurant-style flair to any dinner party dish.

For now, the simplest place to start is with a punnet of local blackberries, some sugar and half a lemon. It’s a nice way to make the most of the local harvest, and to keep the summer going a little bit longer.