• Food

A guide to preserving

  • 30.10.2017

With an abundance of fruit and veg around, there’s no better time than autumn to embrace the age-old tradition of preserving. Get the lowdown with our glossary of the kit, ingredients and techniques you need to know for perfect pickles and jams.

Helps the pectin set. Added late in the process, as lemon juice or citric acid, so as not to harden the skin and spoil the texture.

From the Indian word ‘chatni’, this savoury jam contains fruit and veg cooked with vinegar, sugar and spices to preserve them.

Strawberry jamFruit and veg
In season now for jams, pickles and chutneys are apples, plums, pears, blackberries, quince, tomatoes, onions, cabbages, figs and squashes.

Jam, conserves and preserves
All use sugar to preserve fruit. Some say preserves and conserves are better quality as they contain more fruit than jam. Others say preserves or conserves contain less pectin, so are softer set. We say, “whatever”.

PicklesKilner jar
These have a patented two-part lid that keeps jams, chutneys and marmalades fresh.

Made with citrus fruit, including the peel. Onions also make a delicious marmalade to enjoy with meat and cheese.

A substance in a plant’s cell walls, most concentrated in the pips, cores and skins, that’s released when fruit is boiled and causes jams to set. Apples, pears and quinces tend to have more pectin than berries, which can require supplementary pectin to help them set. This can be achieved with pectin powder, jam sugar with added pectin, or by combining the berries with a fruit higher in pectin. It’s better to use slightly underripe fruit for jam, as it has more pectin.

Beetroot picklePickling
Most often used for vegetables, such as cucumbers and onions. Chopped veg are heated briefly in a mixture of water, vinegar and flavourings, then sealed in sterilised jars and left to cure before eating.

Preserving jar
A wide-necked glass container that is usually hermetically sealed.

Elderflower chutneyPreserving pan
Large and wide, to give the biggest possible surface area, which allows for fast water evaporation, leading to a more concentrated flavour. The quicker the water evaporates, the fresher the product tastes. Choose a stainless steel not aluminium pan, which affects the flavour.

Preserving processes
Various techniques for deactivating or killing the enzymes or micro-organisms that cause a plant to decay. Air and water are the main enemies of jams, chutneys and preserves, as they encourage biological reactions, so the aim is to keep them out. Common methods are drying, smoking, freezing, sealing or coating (with, for instance, a layer of fat), cooking and/or combining the fruit or veg with sugar, vinegar or salt.

Sterilised jars
For storing jams or chutneys without nasties such as bacteria or mould spoiling the goods. To sterilise a jar or bottle, wash the glass and lid (removing the rubber seal if there is one) and place in the oven at 120C/gas 1/2 for 20 minutes, until completely dry. Simmer the rubber seal in boiling water for 10 minutes, then remove with tongs. 

Sugar and salt
Both preserve food by drawing out the moisture and thus preventing the growth of bacteria-inducing microbes.

Sugar thermometer
Jam needs to reach 103–105C for it to set. If you don’t have a sugar thermometer, you can test jam is set by placing a spoonful on a cold plate, then pushing it with your finger – if it wrinkles, it’s done. The jam will firm up slightly as it cools.

Inspired to get preserving? Try our spicy cucumber pickle, mango chutney and cranberry and chilli jam.

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