I used 2 packs of strawberries. Take the hulls off, wash the berries and pat dry. The strawberries weighed 600 g, and I used 300 g of sugar.

Put the strawberries, sugar, and lemon juice in an enamel pan and leave them for a while (preferably overnight).

Simmer over low heat, while stirring occasionally with a wooden spatula. If any scum rises, skim it out.

The strawberry juice will gradually turn a deep dark red. When you stir up the bottom of the pan and the liquid has thickened enough that you can see the bottom for 1 to 2 seconds, turn the heat off. The jam is done in about 40 minutes of simmering.

Sterilize the jars to be used to store the jam for about 5 minutes in boiling water. Take them out of the water and dry them upside down on a kitchen towel.

Pack the jam into jars while it's still hot. Turn them over onto their lids and leave until cool. (This seals the jars air-tight.)

I got 2 and a half jars full from 2 packs of strawberries.

I wrapped up one jar as a present.

To clean up afterwards: Washing a pan after making jam in it is a big job. Wash it as soon as possible using the hot water used to sterilize the jars.

Take the lid off when you simmer the jam. I left the lid on once and took my eyes off of it for a second...it boiled over and stained my stove-top strawberry color.