(Per kilogram of fruit)
1 kg blackberries
1 kg of sugar (granulated sugar works)
3 lemons juice and or grated skins
Add the lemon juice and lemon skin gratings to the blackberries in a large preserving pan and slowly bring to the boil gently stirring occasionally.
When the fruit reaches boiling point turn it down so the fruit is simmering. You can stir it a bit more here so as to break up the fruit into a pulp.
Next add your sugar stir it in and bring the jam back up to the boil to get its setting point. The sugar should be cooked in and dissolved completely before bring the mixture up to boil.
The Setting Point.
This term often causes confusion but it's pretty simple to check
You can test for the setting point with a sugar thermometer and when the mixture reaches the setting point its ready to jar.
If you don’t have one you can use a spoon and an ice cube. Put some of the jam on a large metal spoon and rest the spoon on an ice cube. If the mixture has a thin skin on it then its set
You can also just use a plate. Put some of the jam on a cold plate, and tip the plate slightly. If the mixture has a light skin on it then its set.
Putting the jam into jars
This can be messy so here’s some tips:
1. Get everything ready before you start. Including lids and paper seals if your using them.
2. Put the hot jars onto a tray or something that will be easy to clean
3. Have some plates ready to put the jammy tools onto. Again this makes it easier to clean up.
4. Use a funnel. If you are going to buy one look for a shallow wide funnel if possible.
You can make a disposable funnel out of the top third of a plastic drinks bottle if you don’t have a jam funnel.
Be aware of the jam’s heat and if you want to be make more jam later on, then a jam funnel may be a wise investment.
Cooling and storage
Seal the hot jam jars and allow them to cool on the shelf for an hour or two and then keep them in your fridge until needed.
Jam will keep a long time under these conditions but will sometimes spoil if air or contaminants get into the jar.
When opening your jam for the first time just check the surface to check it hasn't gone off.
Don’t forget to label and date your jam with jam jar labels before refrigerating.
Blackberry Jam is a big favourite jam and one of the easiest to make. Fresh blackberries already have a high pectin content making it easy to achieve a setting point for the jam. In August and September these fruits are available in most hedgerows and by the sides of roads and can easily be gathered from a single early September walk.
This recipe uses ordinary off the shelf sugar and some lemon juice. You can even use your recycled jam jars making this an easy and economical jam to make use of the glut of this readily available fruit.