Notes on Jam Making
- If required, wash the fruit well. Strawberries and raspberries may not need to be washed.
- If the fruit is picked when wet the jam is likely to go mouldy.
- Make jam in small quantities for best results.
- If you use too little sugar the jam may ferment and too much sugar may cause crystallisation.
- The sugar must be completely dissolved before boiling to avoid crystallisation.
- Ideally use a preserving pan for rapid boiling and evaporation. If you don’t have one use your widest pan with a heavy base.
- For the initial cooking of the fruit, cook at a simmer, after adding the sugar always boil rapidly ( at the highest temperature ) until setting point is reached.
- Over boiling will reduce the fresh flavour and appearance of the jam.
- Test for setting point frequently. It should read 105C / 220F on a sugar thermometer.
- Make sure jars, lids and all equipment are spotlessly clean.
- Only use sterilised jars. Place in an oven at 180C for 10 minutes or ideally wash in a dishwasher and then warm in the oven while making the jam.
- Fill the jars almost to the top and seal while still hot.
- Pectin is the natural setting agent in jams. It is found in the skin, seeds and core of the fruit.
- The levels of pectin vary in different fruits. Raspberries, redcurrants, blackcurrants, cooking apples and plums all have high levels of pectin.
- It is best to use fruit slightly underripe as the levels of pectin will be higher.
- Strawberries, blackberries, blueberries and cherries have low levels of pectin and often lemon juice ( which is high in pectin ) is added to aid setting of these jams.
- You can learn about Jam Making in my new Soda Bread and Jam Class.