Preserving fruit and vegetables
Jam

To make jam you need equal quantities of fruit (plums are good at the moment) and sugar plus pectin powder. The latter is not essential but it does ensure that your jam sets well.
Place these in a large saucepan and heat to a gentle boil, stirring regularly (wooden spoon) to prevent the sugar from burning. Soft fruits like raspberries and strawberries do not need extra liquid but plums and damsons can benefit from a cup of water for every kg of fruit.
Boil gently until the mixture reaches the setting point – 105C. This may take half an hour or longer. A sugar thermometer is useful! But if you haven’t got one, dip your spoon in and lift it with the curved surface uppermost. Count to 20 then tip the spoon. If the mixture clings to the bottom edge you have probably reached setting point.
Meanwhile wash and sterilise some jars – 1kg of fruit produces about 5 jars of jam. To sterilise the jars, half fill with water and place in a microwave (without their lids) and heat until the water boils.
Pout the jam into jars and screw on the lids straight away. As the jars cool, the metal lids will contract creating an air tight seal.
The WI has long been associated with jam making: https://www.thewi.org.uk/life-at-the-wi/food-and-cookery/recipes/recipes/jams,-preserves-and-pickles/easy-strawberry-jam
Bottled fruit

Cook the fruit until it is soft. (I do this in a plastic covered box in the microwave). Add water if the fruit is not obviously juicy – eg if preparing plums, apples, quinces etc. Once the fruit is soft (doesn’t need to be cooked to a mush) put into sterilised jars. Press the fruit down so that they are all covered by the liquid that has been released by the cooking. Secure the jar lids. Place the jars in a saucepan and fill with water till it reaches at least half or two thirds up the jars. Cover with a lid and bring to the boil. Boil/ simmer for 15 minutes. This ensures the contents of the jar are all brought to a high temperature to kill of bacteria. Cool the jars and store. As the jars cool the lids will contract creating an air tight seal. As well as jam jars you can use kilner jars.
Chutney
Chutneys use a mixture of fruit and vegetables. I use 3kg of chopped fruit and vegetables -eg plums, apples, marrow – including at least one chopped onion and about 200g of dried fruit such as dates, raisins or figs. To this I add 400g of sugar and 400ml of vinegar and a selection of spices – cloves, ground nutmeg, cinnamon, star anise, chilli powder etc – the equivalent of approximately 2 teaspoons.
Put everything into a pan and bring to the boil, stirring regularly. The chutney is cooked when if you scrape your wooden spoon across the bottom of the pan you can see a clear expanse of pan before the mixture flows back.
Pour into sterilised jars with screw on lids. It is best to allow chutney to mature 6 to 8 weeks before eating.
Chutneys are a good use of green tomatoes: https://www.thewi.org.uk/life-at-the-wi/food-and-cookery/recipes/recipes/jams,-preserves-and-pickles/green-tomato-chutney
Sauerkraut

Sauerkraut is traditionally made with white cabbage but you can add other vegetables and even fruit too. (We add pineapple when we get it in our OddBox delivery).
Take you selection of vegetables – eg firm red or white cabbage, root vegetables such as carrot and beetroot, celery or fennel, garlic, onions, pumpkin – and slice them all thinly. For very 500g add 2 teaspoons of salt. In addition you can add spices such as caraway seeds, fennel seeds, allspice, peppercorns etc. Mix everything together in a large bowl and squeeze and scrunch the vegetables until they produce a liquid. Pack the whole mixture into a large jar with a lid (kilner jars are great) and press well down. The liquid should reach the top. Use a large cabbage leave to cover the top pressing down to keep everything submerged. You can add a weight (wrap in tinfoil first) or even a clean stone.
Over the next few days the mixture will begin to ferment. You will see bubbles forming. You may need to release the lid to allow excess gas to leave.
Classic sauerkraut recipe: https://www.theguardian.com/food/2021/jan/06/how-to-make-sauerkraut-recipe-felicity-cloake
Pickled ‘capers’

Nasturtium seeds can be used instead of caper – don’t use the seeds you buy for sowing but pick ones from plants that you have already grown. Fill a small jar with clean green seeds. Cover with vinegar and add a few spices such as coriander seeds, peppercorns and a bay leaf. Secure with a lid. Leave to mature – they will turn pale brown.
Preserved lemon skins
As you are cooking save lemon skins. Place them in a clean jar with a layer of salt to cover them. As you add more lemon skins, add more salt. Pack the skins in well so as not to leave air pockets. The skins will turn brown and will absorb some of the salt. You can use them as and when you wish, slicing and adding them to salads and casseroles.