The sky has turned an unusual colour (blue), the thermometer is soaring to new heights and at last summer fruits are appearing in abundance after the long cold spring – this is the time to make jam!
Anna Colquhoun, our preserving expert, shares her jam-making tips below and talks about why now is the time to start bubbling up a batch of jam while summer fruit is in abundance around us. If you have any questions just comment on our blog, our Riverford Facebook page or tweet!
The one problem with summer holidays abroad is that you miss out on eating and cooking with local summer produce. (Every year I nurture a row of tomato plants for months only to be away for the bulk of the crop.) Our summer season is short, so to make the most of it I recommend turning your hand to jamming now.
We’ve just held my summer preserving workshops in London. It was so satisfying producing row after row of beautiful filled jars, including strawberry & rhubarb jam, stunning bottled cherries and glowing lemon curd. Many hands indeed make light work. So I suggest getting together a group of friends for a jamming session, or coming to my next Riverford Autumn Preserving workshops in October!
The flavour and beauty of summer treats like cherries, strawberries, raspberries, currants, rhubarb, apricots and gooseberries can all be preserved for months to come with nothing much more than sugar, jars and a large pan. Read on for my top jamming tips…
It should go without saying that you should use beautiful, good quality fruit. Wash carefully, cut out any rotten patches and chop into even pieces. I’m not a huge fan of gimmicky jams. (You know the sort, like Tesco’s Cosmo and Daiquiri ‘Mocktail’ preserves.) However, judicious use of vanilla pods, fresh bay leaves or sprays of lemon verbena can work a treat in with the fruit.
You need pectin for jam to set. Some fruits are naturally high in pectin, such as gooseberries and currants. Others, including strawberries, rhubarb and sweet cherries, have very little so you need to add it. Apricots and raspberries are somewhere in between so might need a little if you want a firmer set. It’s easiest simply to substitute some or all of the sugar in your recipe with ‘jam sugar’, which has pectin in it.
To make a jam that will last on the shelf (unopened) rather than needing refrigeration, use approximately 1kg sugar for every 1kg of fruit. Regular, white granulated is best, or ‘jam sugar’ (see above). Don’t use caster; you might be tempted as you imagine it will dissolve faster, but it’s more likely to catch and burn at the bottom of the pan. The first step is to dissolve every last grain of sugar with minimal heat. You can even macerate the chopped fruit in the sugar in the fridge overnight to start the process. This works especially well for strawberries and helps preserve their shape in the finished jam.
For the pectin to work it needs acid. Most fruit is naturally acidic, but some need the juice of a couple of lemons to help the jam set properly, including strawberries, apricots, sweet cherries, raspberries and – rather surprisingly – rhubarb. Add it to your jam mixture in the pot.
Once all the sugar is dissolved, crank up the heat, boil furiously but watch that it doesn’t boil over. This is why you need a big pan! I found my beautiful old copper preserving pan in my parents’ garage by chance (thanks Mum), which is fortunate since they now cost a fortune. It’s true that copper pans work a treat, but any large stainless steel pot will work fine.
This is the magical moment when syrup becomes jam! Fruits seem to behave very differently, even from batch to batch or year to year, so don’t believe a recipe that tells you to boil for X minutes and then pot. You need to test. A thermometer will give you a good guide – you’re after around 104 degrees Centigrade – but they’re never totally accurate. So I prefer to watch how the syrup runs off a wooden spoon – first in a long watery stream, then in sticky globs that seem to want to hang on – and then perform the ‘saucer test.’
Have some saucers chilling in the fridge or freezer. Pour on a teaspoon of syrup then let it sit undisturbed while it cools. This is your window into the future – a sneak preview of the consistency your jam will end up. Push your finger across the jam and watch for bunching up and wrinkling. If instead it still feels and looks like a syrup, turn on the heat again and boil for another few minutes before testing again.
You have now made jam!
Let it sit for a few minutes so that the fruit settles. Fold in or skim off any unsightly scum and pour into hot, sterilised jars right up to the brim. Carefully screw on clean, new lids and turn the jars upside down for 10 minutes to sterilise the insides of the lids. Just remember to turn them over again before they set!
You can find more guidance here, including instructions for sterilising jars in the oven.
Whether you’re an experienced or novice preserver, please let me know how it goes, ask me any questions and share your own tips by commenting on this blog below, writing on our Facebook page or sending a tweet to @Riverford with the hashtag #cooksquestion.