Wash the raspberries and place them in a large saucepan. Add the lemon juice the lemon and put the pan on the hob over a low to medium heat.

Once the raspberries start to simmer and break down they will release their juices. Once this happens, add the sugar and stir it into the fruit until it dissolves.

At this point you can break up the raspberries further or leave them larger if you prefer a chunkier jam.

Increase the heat so the jam comes to a rolling boil and bubbles away so it gets to a high enough temperature to reach setting point.

I use a thermometer – once the jam reaches 104.5C it’s set. If you are using the wrinkle test method once you think it’s hot enough – maybe after 10 minutes or so – take the jam off the heat and retrieve the saucer from the freezer.

Spoon some jam onto the cold plate and place it in the fridge. After a couple of  minutes take it out of the fridge and push the jam gently with your finger, if it wrinkles it's ready. If it doesn't - return the jam to the heat for 10 minutes and try the test again.

When the jam is ready, skim any scum off the surface of the jam and discard this. This will give you a clearer jam. 

Let the pan of jam cool in the saucepan for ten minutes before bottling.

Now, pour the jam into sterilised jars being careful as it’s scorching hot. If you have one, use a jam funnel to make the job easier.

Screw the lids on tightly and leave to cool. Store in a cool, dry place.