If you want to make green gooseberry jam you have to use very firm, slightly under-ripe green fruit. I have used a mixture of mostly firm green cooking gooseberries and a few of the deliciously sweet red dessert gooseberry, Hinnomaki Red. While the forest garden was in all its bounty, I added a few jostaberries and worcesterberries too. It is thought that whilst the Jostaberry is a hybrid cross of currant and blackberry, Worcesterberry is a form of the North America species – Ribes divaricatum. They both make a vigorous thorny bush, much bigger than blackcurrants or gooseberries but are not quite as productive in my garden. I do like them, however, as they add another dimension in height to the forest garden and their redder pigments give the jam a delicate rosy colour.
4 lbs (1.8 kg) gooseberries
1.7 pints (1 litre) water
6 lbs (2.7 kg) sugar
Top and tail the gooseberries. Put the fruit and water into a preserving pan or a big saucepan with a heavy base. Be careful not to add too much water. If your fruit is ripe, add less. Bring to the boil and simmer gently until the skins are soft. Then add the sugar slowly on a low heat, allowing it to dissolve. Be careful not to put it all in at once and boil before the sugar has dissolved as it may crystallise during storage. Once dissolved, bring the jam to a rapid but steady boil and boil until it reaches a temperature of between 105°C and 110°C. This should take about 15 minutes unless you have added too much water.
Wash some jam jars in hot soapy water and rinse well. You can put them into a preheated oven at 160°C/fan140°C/gas 3 until you
are ready to use them but I never bother. I just make sure they are very clean.
I own an old brass kitchen thermometer and along with my preserving pan, it is a treasured possession given to me by my mother-in-law. I suggest you see if an elderly relative has one surplus to requirement or seek one out at a car boot sales. I find it invaluable for wine and jam making. It tells me exactly when I have reached setting temperature.
If you don't have one you can do a wrinkle test. Place a saucer in the freezer when you start the jam. Take a teaspoon of the jam and put it on the saucer. Let it go cold. Then push it across the plate with your finger. If it is ready it will wrinkle up. If not, keep on boiling the jam mixture for a few more minutes.
Once you have set the jam take it off the heat and let it sit for a while so that it stops boiling. Then ladle it into jars. Again, I have a special funnel which saves a lot of mess and makes ladling a quick and clean process.
Leave to cool. Label. Enjoy!