You need very little special equipment.
For cooking my jams and preserves, I use a large, enamelled, cast-iron casserole dish. You need a pan about 15–20cm/6–8in deep, and one that is also wide enough to give a large surface area: this makes the boiling process as quick as possible, allowing a rapid evaporation of water. Preserving pans work well but are an unnecessary expense unless you are intending to make industrial quantities of jam.
If you are nervous about something like a curd ‘scrambling’, you could use a double boiler instead of an open pan.
You will need a long metal spoon to stir the jam, and several small plates or saucers in the freezer with which to test for a set. A slotted spoon is useful to skin any scum from the surface of the boiling jam.
Jam jars with lids are best, though you can use wax discs and cellophane seals in the more traditional manner. Both jars, lids and seals can be bought from home-ware companies, but I save pretty-shaped jars with their lids ready to use again.
A jam funnel will be of tremendous use when filling the jars. For marmalade, you will also need a square of muslin, in which to tie up the pips and pith, and, of course, you will need a jelly bag if you are planning to make a jelly – along with some way to support it over the bowl into which it will drip.
Everything to be used in preserve-making – jams, marmalades, pickles and condiments – needs to be spotlessly clean and should be sterilized before use. A dishwasher does this effortlessly, but a good scrub in hot soapy water works just as well. If you’ve washed glass jars, for instance, a spell thereafter in a hot oven – about 20 minutes at 160°C/320°F/Gas Mark 3 – will make sure any bacteria have been dealt with. Taken straight from the dishwasher, this stage can be omitted. Lids have to be sterilized as well, as do all the other pieces of equipment, such as spoons, ladles, funnels, etc.
Cooking Your Jam
The prepared fruit, lemon juice if needed, and sugar are placed in the pan and gently heated. You must stir from time to time until the sugar has dissolved.
Then, to get the freshest flavour with the quickest set, the jam should be cooked over a high heat for as short a time as possible. The jam should boil rapidly but must be stirred occasionally to ensure the jam doesn’t catch.
Testing for a Set
Once the jam or marmalade has been boiling for the time given in the recipe, you will need to start testing for the set. You can tell with a little experience when this point is near: looking at the jam, the boil becomes more sluggish (the bubbles will ‘plop’ rather than froth), and a spoon of the jam cooled slightly then tipped back into the pot begins to hold together.
The most efficient way to test for the set is to take a chilled plate from the freezer and drop a teaspoon of mixture on to it. Wait a couple of minutes for the jam to cool, then begin pushing the edge of the mound of jam. If a skin has formed and the jam wrinkles, it’s ready. If the jam is still liquid it is not ready, so return the pan to the heat and boil rapidly, testing as above every 2–3 minutes. You must take the jam off the heat while you test for a set. And now that you are so near setting point, stir the mixture often to prevent it sticking and so burning.
Potting and Labelling
Once you are happy that your jam or jelly has reached setting point, you will need to proceed with potting while it is still hot. I usually leave the jam to settle for about 5 minutes before potting, as this makes the whole process a little safer.
Have ready your clean sterilized jars and lids, funnel and ladle. The jars should be hot when filled with the preserve, so place them on a baking sheet in the oven heated to 160°C/320°F/Gas Mark 3 for 15 minutes.
I take the hot jars on the tray and place them close to the preserving pan. Using the jam funnel – or you could pour the jam or marmalade from a jug – fill the jars with the hot mixture, leaving about 1.5cm/⅝in headspace. Try not to dribble the mixture round the top of the jar.
If using wax discs, place these on the hot jam at once, then cover with the cellophane covers. If using lids, place them on the hot jars, and then tighten later once the jars are cool.
Do label your jars clearly, to avoid problems later. You might think you’ll remember what jam is in which jar but, trust me, you won’t! For instance, some chutneys can look remarkably like jam… You’ll need to write on the name of the preserve, plus the date it was made. (You can get very pretty labels from mail-order outlets and some stores, or you can just use plain ones from stationers.)
Store your jams, jellies and marmalades in the larder or pantry in wonderful serried rows where you will be able to admire your handiwork. If you have a cold room – even a garage – this will also work well. Some of the preserves in this chapter are best kept in the fridge.
Reference: Thane Prince (2015). Pickles, Preserves and Cures: Recipes for the Modern Kitchen Larder. London, UK: Pavilion Books.