There are many ways to preserve our harvest when too much ripens at once. Horticultural Advisor Caroline Mazzey explores her favourites

It’s a joy to serve your own fruit jelly with Christmas dinner, or savour homegrown sweetcorn in January. Now with fewer mouths to feed at home, Caroline has plenty of produce from her allotments to preserve and share later. So what to do with it?
Now that I have surplus homegrown food, I need to find ways to make my harvested fruit keep for as long as possible. There are two main considerations – firstly, to keep spoiling organisms like bacteria and fungi in check, and secondly, to slow down internal deterioration of the fruit as much as possible.
Keeping microbes at bay can mean removing water, removing air, or making their world acidic (with vinegar) or too ‘strong’ with sugar or salt. Translated into my kitchen, that means freezing, drying, pickling, or making jams and chutneys – I’ve never tried salting.
Preventing fruits’ own progress towards over-ripeness often means a quick pre-boil or blanche to denature their own ripening enzymes, followed by freezing.
Blanching sweetcorn in a pre-boiling pan of water works very well. Cutting the tip off first is recommended, as this is where any bugs are more likely to be.
When you first put them in the pan, it takes a little while to get back to boiling as they’re so chunky. Then it takes a few more minutes to cool them in icy water to stop them cooking further.
The simplest way of preserving crops that naturally don’t have a high moisture content is to dry them. Threading chillies using a needle and thread and hanging them up somewhere with good air flow is easy and very decorative. Sometimes I find it hard to use them, because I don’t want to lose the colourful ornament I have created.
I make jam all summer already, but at this time of year, it’s likely to be blackberries, which are made into bramble jelly (below) once they are boiled and the pips strained out.
These will be followed by grapes. I crush and press my grapes to extract the juice. Then I gently heat the juice until it almost boils, but not quite. I keep them close to boiling for a few minutes to pasteurise – boiling would change the flavour – and then bottle.
The juice lasts for a few weeks before starting to ferment. A slight fizz is actually delicious, but I have long ago given up on making wine, as it was always dreadful.
Lastly, apples and pears can be stored dark and cool, the idea being that they don’t over-ripen but also don’t dry out. The fruit must be slightly under-ripe as it is going to continue to ripen slowly – you can’t expect ripe fruit to do anything but go over. If my apples are already ready to eat, then I cook them to pulp and store as apple sauce. For storage of under-ripe fruit, a temperature between 3 and 7 degrees is ideal, but no colder.

Fruits should not be touching, so wrapping in paper works well for separation and also soaks up any excess moisture. Don’t go mad with the wrapping though, as you should regularly check the fruit to throw out any which have turned. Pears nearing ripeness need checking almost every day.
Arranging the fruit in single layers rather than stacking them is best practice, though with care, I often do a double layer in slatted boxes for good air flow. Personally, I find that cooking apples are most successful as they’re going to be cooked anyway, so if a certain amount of trimming is needed, it doesn’t make much difference.
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Pick of the crop
Look for the RHS Award of Garden Merit (AGM) when buying vegetable seed or small plants. You can also download the RHS lists of recommended cultivars.
About the author – Caroline Mazzey
Caroline is an RHS Horticultural Advisor based at RHS Wisley, with allotments and a large family!