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The beginner's guide to pickling and preserving: salting, fermenting, bottling – and ketchup making

Bottled Fruit
Stashing away a pile of fruit and veg is a great way of making food provisions last longer Credit: Haarala Hamilton

Preserving food is a long-term investment into future dinners and, now that self-isolation has been enforced as part of the coronavirus crisis, there has never been a better time to start. 

Despite mass panic-buying of dried goods, flour and eggs, shoppers can usually find root vegetables in the supermarket. Vegetables and fruit including cabbage, cucumber, carrots and peaches, to name a few, can be transformed with a splash of vinegar and herbs. And it's such an  easy way to add texture or flavour to dishes.

Pickles and ferments are intended to stretch ingredients out for long periods of time, saving money and preparation time. You don’t have to be a gardener to have a glut to preserve, either. I’m in awe of readers with verdant vegetable patches, but those of us with less than green fingers can still revel in the produce in the greengrocers and markets – better spots than supermarkets to pick up boxes of bargain fruit and veg.

Even battered apples can make excellent purées for freezing or bottling, and overgrown courgettes are good for chutney.

And while jam and chutney are the traditional recipes to pot up, why not broaden your scope with ketchup, ferments and bottled fruit, beans salted the way your grandmother might have, and dried vegetables that can be eaten as they are or rehydrated. 

Drying fruit and vegetables

Drying courgettes and other thin-skinned summer squash like patty pan squash is a great way to store them. The slices can be nibbled on as they are – try brushing the slices with soy sauce before you dry them for extra flavour – or briefly plunged in boiling water to rehydrate. Serve them dressed in melted butter, olive oil and garlic, or tomato sauce. They will have more texture than fresh courgettes, and are less likely to go soggy, which makes them great as a vehicle for pasta sauces.

How to make: courgette crisps

Courgette crisps are a tasty snack and great when rehydrated in pasta sauces
  1. Slice the courgettes thinly using a vegetable peeler or mandolin, working around the core. (The seedy cores can be added to soups.) Patty pan squash can be sliced right through. The important thing is to keep them an even thickness, otherwise some will brown before the rest are completely dry.
  2. Lay on baking sheets lined with baking parchment. Turn the oven to its lowest temperature (without fan), 50-60C is perfect, but if the lowest is 100C then prop the door open slightly. Or put in a dehydrator set to 57C.
  3. If you have used a vegetable peeler to make paper-thin slices, they may be dry after two hours; 3mm-thick slices will probably take twice as long, and they will need to be turned half way through.
  4. Once the slices are completely dry, pack them into an airtight container. They will keep at least a month, probably much longer, provided they are kept completely dry.

Salting

Until the advent of freezers, salting was one of the most common ways of preserving runner beans. My bible in these matters is The Domestic Preservation of Fruit and Vegetables, first published by the Ministry of Agriculture and Fisheries in 1929. It’s a dry title for an amazingly useful book, which I was introduced to by Mrs Pat Lenane (who turned 102 this year). Mrs Lenane leant me her well-used copy, pointing out to me that back in those days wasting food was unthinkable, so the recipes had to be absolutely bullet proof.

While freezing makes sense for most of a large crop of beans, salting is an interesting alternative. It does make them salty – obvs, as my daughter would say – so soak them in a big bowl of cold water for 12 hours, draining and replacing the water twice during this time, before cooking in a big pan of unsalted boiling water. The best salt to use is preserving salt or rock or sea salt, none of which have any additives, but you can use ordinary cooking salt too.

The Domestic Preservation of Fruit and Vegetables recommends sealing the jar with a cork and painting over the top with paraffin wax, but a glass or plastic lid will do just as well – just not a metal one as the salty liquid is corrosive.

The jars may seep a little brine, so don’t store them on a surface that could be damaged.

Bottling

Bottling is called canning in the US, even when its done in glass jars rather than metal canisters. It’s different from jams and pickles, because rather than relying solely on sugar and vinegar as preservatives, the jars, once filled, are “processed” – cooked at a precise temperature for a specific length of time, sterilising the contents. As the jars cool, the contents contract and it creates a vacuum seal, too.

Traditionally the processing is done in a pan of boiling water or a pressure cooker, but you need to be able to immerse the jars completely, which means having a big, deep pan. I find it simpler to process the jars in the oven.

It’s a satisfying way to stock up a pantry and bottled fruit is very versatile – simplest of all, you can just open a jar to eat for pudding, but it’s also great in crumbles and pies.

Vegetables, with their lack of natural acidity, are trickier candidates for bottling, so start with fruit. I love to use plums, a brilliant way to store a glut, not just because the glowing jars look beautiful, but because you can infuse them with all sorts of flavours – herbs, spices, citrus – in the jar. Then it’s the simplest pud of all, just a case of opening a jar and reaching for a pot of cream. You can use the fruit in pies and crumbles too – save the syrup to dilute and use as a cordial, or for poaching more fruit in.

A one-litre jar holds about 750g whole plums plus 350ml liquid, or about 900g stoned plums (weighed before stoning) plus 200ml liquid. If you are using 500ml jars you will have to allow for extra liquid (i.e. more than half the amount of a one-litre jar).

How to make: bottled plums

  1. Choose plums of the same size and ripeness, and as always with preserving, make sure the jars are scrupulously clean and sterilised.
  2. For plain bottled plums, put 400g sugar in a pan over a medium heat and pour over 500ml of boiling water. Stir to dissolve the sugar, then simmer for one minute.
  3. Turn off the heat and add 500ml cold water. Leave to cool.
  4. Pack three one-litre jars with roughly 2.25kg whole plums (it depends on their size and shape) and pour over the syrup. Tap the sides of the jar to get rid of any air bubbles.
  5. Cover the jars with the lids loosely screwed on (screw them until you meet resistance, then turn back a quarter turn), or with spring clip jars close them fully. Stand them in a roasting tin lined with a thick layer of newspaper, to absorb the drips – there will be plenty. Bake the jars for 50 minutes (60 minutes for jars two litres or larger). Remove from the oven and tighten lids. Use oven gloves (spring clip jars will not need tightening). Leave to cool.
  6. The next day, unscrew the band (for Kilner-type screw jars) or undo the spring clip – the flat lid should remain attached – it shouldn’t budge even when the jar is tipped. For regular lids, the centre should have popped down, so that when you press it there is no flex. It will then pop up when you open the jar.
  7. Store in a cupboard. They should keep easily six months, and for up to a month in the fridge once opened.