(Makes 240ml of jam)
100g pectin sugar, warmed in an oven of 120C for 15 mins.
1 lemon, juice of
In a saucepan, heat the raspberries, warmed sugar and lemon juice, stirring occasionally until all the sugar crystals have dissolved. Bring the pan to a rolling boil and cook for 7 mins.
Take the pan off the heat and spoon a teaspoon of jam onto a saucer (from the freezer) and test the set by running a spoon through the jam, if it forms a crinkle and is gel like, then the jam is ready to pot up. If the jam isn’t ready continue boiling for another 2 minutes and re-test until ready.
Pour the jam into the jars, filling the jars as near to the top as possible. Put a waxed disc (cartouche) over the surface, then seal.
Store in sterilised jars in a cool dark place and refrigerate once opened.
Wash your jars in the dishwasher, fill with boiling water and then leave to dry.
N.B. Basic Jam making information:
Sugar has a hardening effect to fruit, so tough-skinned fruits, (plums, gooseberries, etc) should always be simmered before the sugar is added to the pan.
Warming the sugar beforehand helps to dissolve the sugar quickly and keeps the jam boiling evenly.
The sugar should be completely dissolved before the jam reaches boiling point, otherwise it will be difficult to set and the finished jam can be grainy.
Testing whether the sugar has dissolved – dip a spoon in the jam and turn it over, if no crystals are visible in the jam that coats the back of the spoon it has dissolved.
Don’t worry if any scum rises to the surface while the jam is boiling – if you keep skimming it off, you’ll finish with no jam at all. Instead, wait until you have a set, then remove the jam from the heat and stir in a small lump of butter, which will disperse the scum.
With jam containing whole fruit, such as strawberry or damson, or chunky marmalade – let the jam cool a bit before pouring in the jars as this will prevent the fruit from rising to the top.
Don’t put the labels on until the jam is cold – as sometimes the heat will prevent them from sticking properly.
Store in a cool, dry, and preferably dark place. Too much light is not good for storage, while a damp or steamy atmosphere can cause mould to develop on the surface of the jam.
If things go wrong: if the jam hasn’t set after cooling and potting, tip it all back into the pan and boil again, adding the juice of a small lemon.
The ratio between fruit and sugar varies: with sweet fruits, it’s about 2:1 (2 kilos of fruit to 1 of sugar), while with more bitter fruits like oranges, it should be more like 3:2.