Knowing how much pectin is in fruits will allow you to create your own jams with whatever seasonal fruit you have.
To test how much sugar is needed for a specific fruit to make jam – spoon 5ml of the fruit liquid/pulp into a glass and stir in 15ml methylated spirits:
- If it forms a fairly solid, jelly-like clot, the fruit is high in pectin and it will jell quickly, so cooking time will be short.
- If several small clots appear use 180ml sugar to every 250ml fruit.
- If the mixture doesn’t clot or clots are tiny, the fruit is low in pectin, use 125ml sugar to every 250ml fruit and add a squeeze of lemon juice when the sugar has dissolved.
Know your fruit
Fruits that are best for making jam are the ones with a good acid and pectin balance like green apples, grapes, plums, citrus and gooseberries. Slightly under-ripe fruit works best.
FRUIT WITH HIGH PECTIN AND LOW ACID – Sweet apples, guavas, quinces. To increase the acid content add 30ml lemon juice for every 1kg of fruit.
LOW PECTIN/HIGH ACID – Pineapples, apricots, under-ripe peaches and rhubarb. To increase the pectin content, add 30ml lemon juice for every 1kg of fruit.
LOW PECTIN AND ACID – Berries, melons, pears and cherries. Use 125ml sugar to every 250ml fruit and add a squeeze of lemon juice when the sugar has dissolved. If this also doesn’t work, add commercial pectin, following the packet instructions.
Now try your hand at a few our our favourites:
Feature: Margie Els-Burger assisted by Nomvuselelo Mncube images by Caxton photographers and Fotolia.com