Aga Blackberry Jam 

Aga Jam Making Tips and Recipe

As summer peaks and thoughts of Autumn creep in, the humble blackberry begins to appear in our hedgerows. A favourite for adding to fruit pies and crumbles, blackberries make a delicious jam too.

Blackberries are naturally high in pectin, which is what helps the jam to set. This makes it a great fruit to try if it's your first time making jam. You don’t need to add extra pectin or buy fancy jam sugars, so it's as easy as, well, blackberry pie!

Finding the right quantity of fruit can be tricky. The general rule of thumb for jam is 1:1 equal ratio of fruit to sugar. However, due to the pectin content in blackberries, you can use less sugar. A modern approach is to use a ratio of 4:3. 

Tips for Making Jam on an Aga

An Aga is fantastic for making jam. The cast iron hotplates are perfect for hitting the right temperatures needed for softening and then boiling the fruit. An ElectricKit converted Aga is brilliant too, with full hob temperature control and ceramic and induction hob options, helping you hit and hold the right temperatures needed.

The ovens are also useful in the jam making process. Use your simmering or warming oven - or ElectricKit Aga oven set to 110-120c - to dry and sterilise your jars. Leave them in the oven while you are cooking the jam. Ensure the jars are still hot when adding the hot jam, otherwise you risk cracking the glass.

Use a thick bottomed pan. A jam making pan is perfect as the thick bottom prevents burning even at high temperatures, and ensures even heat distribution for a controlled boil. 

A temperature probe can help you determine when the jam reaches setting point, which is around 104 degrees centigrade. At this temperature the sugar and pectin begin to form a gel. The old fashioned method is to use the back of a plate. Blob some of the jam onto a cold plate and let it cool for a few seconds. Gently push the jam with your finger. If it wrinkles when pushed, then it has reached setting point. 

Ingredients and Method:

To make blackberry jam, use a ratio of 4:3, fruit to sugar. To make one large jar of jam we used: 

• 720g of blackberries 
• 540g of caster sugar. 
• Approx 2.5tbsp of lemon juice (Use juice of half a lemon per 500g of fruit. This helps activate the pectin to aid setting.)

1. To sterilise your jars, first thoroughly wash in warm soapy water and rinse. 
2. Place on a baking tray in either the simmering or warming oven of your traditional 2 or 4 oven Aga. If you have an ElectricKit Aga, set your oven temperature to 110-120 degrees centigrade. 
3. Leave them in the oven while you are making your jam and remove once the jam has reached the setting point. 
4. In a large, thick bottom pan, add the fruit and lemon juice and use the simmering plate (or ElectricKit setting 4) to soften the fruit. Once soft add the sugar, stirring until fully dissolved.
5. Use the boiling plate (increase the temperature on the ElectricKit hotplate, or use the ceramic/induction hob) to bring the fruit and sugar mixture to a rolling boil for 8-10mins, stirring occasionally, until it reaches setting point.
6. To check if your jam is set, dab a little on a cold plate and tip it. If it runs, it still needs a little cooking, but if it wrinkles when you touch it, you're ready to go! Careful not to overcook jam or it will turn to toffee.
7. Carefully spoon the jam into your sterilised jars while the jars are still hot.

Discover more Aga recipes

Whether you are new to Aga cooking or are looking for inspiration, our recipes page is packed with delicious and tasty treats that are easy to whip up on your cast iron cooker.