Makes about five 340g jars of bright red tangy jam. Time needed: about an hour if fruit is already frozen otherwise start te day before.
This recipe calls for the fruit to be frozen as an alternative to the usual method of stewing down before the sugar is added. The effect is the same; the cells are broken down, but freezing is kinder and helps keep the color of the fruit.
Jam gets very hot while processing. Take care
Jam spilled on a hot ceramic hob to such one with halogen rings will chemically bond to the ceramic leaving a permanent mark. Induction hobs do not get hot enougth for this to happen, in my experience.
1100 - 1200g raspberries
1000g sugar - whiteor golden caster but not jam sugar
juice of half a lime
thermometer - (note: induction hobs can fry digital thermometers but remote probe models see to survive)
oversize saucepan - allows for foaming and spitting
six (five and a spare) clean used supermarket jam jars
- Freeze the fruit the day before you start, if not already frozen
- Put sugar in a roasting pan into oven at 40°C to warm along with the jam jars
- Tip the frozen fruit and lime juice into a pan over medium heat
- Stir to stop catching until fruit is thawed and liquid
- Tip the sugar into the fruit pan and stir to dissolve
- Turn up the heat and keep stirring
- Boil fast, watching the temperature. Don’t worry about scum forming on top - it will disappear when the temperature gets to about 103°C. The temperature may stick at about 103°C when the mixture starts to clear and look like jam.
- As soon as the temperature reaches 104°C draw the jam off the heat, wait a moment or two and pour it into the warmed jars. Be very careful of the hot jam
- While still hot, clean round the tops of the jars and screw the lids on tight