Make fresh jam at any time of year by using a packet of frozen mixed berries. Quick to make with an easy small batch jam making technique.
Add all the ingredients to a large saucepan, and let stand for at least one hour as the fruit defrosts. This can be overnight.
If using the wrinkle test for the setting point, place a couple of side plates in the freezer.
Heat the mixture on a very low heat to allow the sugar to dissolve and the fruit to release its juice. Stir gently occasionally.
Heat jam jars in a low oven to sterilize - 100°C/220°F/Gas Mark 1.
Once all the sugar has dissolved, turn up the hob and heat the jam quickly to a rolling boil. After a couple of minutes, start testing the jam's set using your favourite method.
Temperature: use a jam thermometer, and check to see that the jam has reached 105°C/221°F.
Wrinkle: spoon some hot jam onto a chilled plate and see if it wrinkles ahead of your finger when pushed through the jam.
Flake test. Allow the jam to run off a spoon with the bowl held vertically. When a flake of jam remains attached to the lip of the spoon, it's reached the setting point.
Once the jam has reached the setting point, turn off the heat and allow it to cool for about 10 minutes. This allows the jam to thicken slightly, so that the fruit pieces don't all float to the top in the jars.
Spoon the jam into the hot jars and seal the lids. Allow to cool completely. Label and start enjoying fresh, three ingredient jam!