I've alluded to how easy jam-making is in a few posts now so I thought I'd take a moment in between the money stuff to explain how I make it. For those who have never tried doing it before I'll go through the basics of jam making and then give you a simple method to make in the microwave.
The two basic ingredients for making jam is fruit and sugar, with the amount of sugar used depending on the type of fruit. There's a lot of myth and magic banded around about jam making, one of which is a substance called pectin. All fruits contain pectin to a greater or lesser degree. It's a complex carbohydrate, or starch, that occurs in the rind and core of the fruit where it adds support to cell walls. Boiling the fruit when you’re making jam causes the pectin to be extracted and it is what helps the jam set. However, although many recipes recommend buying commercial pectin to add, I have NEVER added pectin to any jam I have ever made and my jam sets. It's accepted that making large batches of jam that need a lot of cooking cause pectin to break down and I believe part of my jam success is that I tend to do small batches that cook quickly, thus retaining the pectin.
Before you say it, that set of rhubarb jam I mucked up was probably due to making too much at one go in the saucepan and not using enough sugar to achieve a quick set. I have since made a successful small batch using the basics of this recipe.
The other thing that helps a jam set is acid. Again, all fruits have acid in them to a greater or lesser extent, but those naturally low in acid will need lemon juice added to help the jam set. Now don't get all worried and think about finding a list of these low acid fruits. The recipes I'm going to give you here should get you started without the need to hunt for lists.
One more thing. Never use overripe fruit for jam. Not only does the amount of pectin etc break down in fruit that is past its best, but you also run the risk of adding deacy bacteria to your jam.
What equipment do you need?
Before you start, read the instructions thoroughly and you lay out the equipment so it's all to hand so you can move smoothly between stages once you get started. When I say equipment, don't run out and get a preserving pan and a bundle of expensive Le Parfait jars. It's not necessary. As much as I would love a copper preserving pan it's not a necessity and might actual prove more difficult to get the hang of using then the microwave. The only exception to this is if you want to make huge quantities at one time and then a pan might be a good investment, but don't hurl yourself into making a large batch straight away - build up to it.
Generally speaking a pound of fruit made to one of the recipes below will fill 2 jam jars plus half of a third. If you don't eat jam quickly be careful how long you store that half pot. The large volume of air in the jar makes it more likely for bacteria to develop quickly, especially if you poke a knife in there every now and then.
So equipment. The following will do the job nicely:
- Microwave - the recipes below are optimised for an 850W microwave. A more powerful one will need less time cooking so try testing for jam set 2-3 minutes before the times indicated in each recipe. A less powerful microwave may mean more time cooking time, but cook to the time specified in the recipe and then go from there in 1 minute increments.
- A set of waxed inserts, polythene circles and rubber bands - eBay and John Lewis sell these sets very cheaply. You will need to make sure your waxed inserts are the right size for the neck of the jar BEFORE you do the jam. If they're too big simply cut them down with sharp scissors.
- Empty jars - preferably jam or honey jars but at a pinch an old dolmio sauce jar etc will do.
- A pyrex jug - jam reaches temperatures higher than boiling water (around 115oC) and you can easily crack a nice jug if it's not heat resistant.
- A pan trivet or something that will protect your work surface as you're going to plonk a hot saucepan on it
- Either greaseproof paper or foil
- A large deep bowl - I have a beige-coloured Mason Cash bowl that I use. The sides need to be deep as jam really boils high when it gets going and you don't want it boiling over.
- A freezer proof saucer - in the absence of a jam thermometer this is needed to test the set of the jam by the 'wrinkle test'. By the way, you don't really need a jam thermometer. I've trashed two in six months and have gone back to using other methods to test for set (see below).
- Double mitten-type oven glove
- A clean tea towel
- Several pieces of wet kitchen roll
Basic method
- Put the saucer in the freezer an hour before starting. this will be used to test for set (see below).
- Preheat your oven to 100oC
- Wash your jars in hot soapy water, rinse thoroughly in hot water and then lay then neck side down on a sheet of greaseproof paper or foil in the oven. The purpose of this is two-fold. You need to make sure the jars are heated a little before you put the jam in to avoid them cracking and the high heat helps keep the bacteria off while you make the jam.
- Wash and prepare the fruit, then cook in the microwave (with water if the recipe requires it) for the amount of time indicated. DON'T USE MORE THAN 1.5lbs OF FRUIT AS THE JAM WILL RISE OVER THE SIDES OF THE BOWL.
- Add the sugar and stir well.
- Cook for the amount of time first indicated in the recipe and then test for set.
Testing for set
Drop a tiny amount of the jam mixture onto the plate you have just taken out of the freezer. Let the jam cool slightly for a few moments then - holding the plate into the light, - push your finger into the jam (that tiny amount will have cooled so you won't get burnt). If the skin on the jam wrinkles in front of your finger the jam has set and is ready for potting. If the jam is still too runny, let it cook for another minute and then try again.
Potting the jam
- Once set is reached, put on your oven gloves, take out the bowl, put it on the trivet and let it cool for a couple of minutes.
- Spread your clean tea towel onto the work surface and place your hot jars from the oven on top.
- Transfer the contents of the bowl into the pyrex jug then carefully pour the hot jam into each jar stopping within an inch of the top.
- Add a wax disc to the surface of the jam, taking care to lay it out gently and slowly to avoid trapping air bubbles.
- Use a wet kitchen towel to wipe off any excess jam that has spilled on the inside of the jar above this wax disc and on the outside of the jar.
- Take a polythene circle and wipe with a fresh piece of wet kitchen towel.
- The circle will start to roll and crinkle. Stretch it gently across the top of the jar, smoothing it round the sides with your hands and then add an elastic band to keep it in place. Make sure there are no creases or raised areas. This is vital if you are to seal your jam so no air or bacteria can get it. The water on the polythene helps create a vacuum as the jam cools. You'll know when a vacuum has formed because the outside rim of the plastic will develop wrinkles and you may even hear small pinging noises as the plastic stretches.
- Leave to cool completely before adding a label.
JAM RECIPES
Plum jam
1lb of plums
1lb of granulated sugar
1/3 pint of water
Wash, stone and halve plums into the bowl. If you want you can also remove the skins, but it's not absolutely necessary. Add water and heat uncovered on full power for approx 6 minutes or until the fruit is soft and water reduced to approx 1/3 of the quantity. Add sugar and stir well. Cook on full power for approx 20 mins or until setting point is reached.
Raspberry jam
1lb raspberries
1lb sugar
Wash fruit and add to bowl. Microwave uncovered on full power for 5 minutes.
Add sugar and stir well. heat on full power for 12 mins or until setting point is reached.
Blackberry jam
1lb raspberries
1lb sugar
Wash fruit and add to bowl. Microwave uncovered on full power for 5 minutes.
Add sugar and stir well. heat on full power for 15 mins or until setting point is reached.
Nectarine jam
1lb chopped nectarine flesh (stoned and skinned)
1lb sugar
1/3 pint water
1tbsp lemon juice
Wash fruit and add to bowl. Microwave uncovered on full power for 9 minutes or until soft and water has reduced by 1/3.
Add sugar and lemon juice and stir well. Heat on full power for 18 mins or until setting point is reached.
Blackcurrant jam
1lb blackcurrants
1.5lb sugar
1/3 pint of water
Wash fruit and add to bowl. Microwave uncovered on full power for 12 minutes or until soft and water has reduced by 1/3.
Add sugar and stir well. Heat on full power for 10 mins or until setting point is reached.
Gooseberry jam
1lb gooseberries
1lb sugar
1/3 pint of water
Wash fruit and add to bowl. Microwave uncovered on full power for 12 minutes or until soft and water has reduced by 1/3.
Add sugar and stir well. Heat on full power for 10 mins or until setting point is reached.
Strawberry jam
1lb strawberries
12oz sugar
1 tbsp lemon juice
Wash and hull the strawberries. Microwave uncovered on full power for 5 minutes or until soft.
Add sugar and stir well. Heat on full power for 11-12 mins or until setting point is reached.
Rhubarb jam
1lb rhubarb
1lb sugar
1tbsp lemon juice
*****requires preparation the day before making the jam*****
Cut up the rhubarb into half inch pieces, add to bowl and cover with the sugar. Cover the bowl and leave overnight. The next day you will find the sugar has softened the rhubarb and caused the water to leach out to form a syrup (at this point you can dilute this to make a great cordial if you don't want to make jam and use the rhubarb for something else like a fruit crumble. Just make sure you keep the cordial in the fridge and drink it within a 10 days). Add the lemon juice, stir the bowl contents and heat uncovered on high power for 18 minutes or until the setting point has been reached.
And there you have it! Jam.
I tend to make different jams according to what's ready in the garden and what's on special at the supermarket. If any fruit is on a BOGOF or at half price I get it and turn the 'free' amount into jam.