Strawberry jam - the template

This works for me, every time

Ingredients:
strawberries, hulled and wiped over, if necessary with any bad bits removed.  Don't wash them.  Cut any enormous ones in half
jam sugar

I know jam sugar is more expensive but it is reliable, more reliable than adding lemon juice, in my experience.  I've never had a failure with jam sugar.  You find it with all the other sugars in the shops.  Don't mistake it for preserving sugar, it's quite different.  Jam sugar has the added pectin that you need to get a good set.

Method
Weigh the hulled and cleaned strawberries.  Whatever they weigh, you need three quarters of that weight in jam sugar.  So 1k of strawberries will need 750g jam sugar.

(an easy way if you have a calculator is to input the weight of the berries and multiply by 0.75 to get the weight or sugar)

Put the berries in a large bowl.  Pour over the sugar.  Stir it in gently so that all the berries are in contact with the sugar.  Cover and leave for a few hours, I would say a max of three hours.

Place your saucers in the fridge or freezer.

Put the berries and sugar in a large pan.  Slowly heat them on low, stirring regularly.  Don't allow the mixture to boil until every bit of sugar has dissolved.

Bring to a rolling boil, then take off the heat and leave it to stand for a few hours or even overnight.  This is my own discovery and I find that setting point comes so much faster if I do this and therefore the taste is 'fresher'.

Put your clean jars in a warm oven - the sort of temperature for heating plates.

Reheat to boiling, stirring.  Allow to boil for a couple of minutes and take off the heat while you use a saucer in the fridge to do the wrinkle test.  I usually find that the jam is has reached setting point but if it hasn't, reboil and retest.  Take the pan off the heat while you are testing or it may over-set.

When ready, pour the jam into your clean, warmed jars and put the lid straight on.  Be careful, it is VERY hot at this stage.

Allow to cool, wipe the jars if they are sticky, label and store in a dark place.