Wash gooseberries and remove blossom and stem ends. Put in large pot, crush some of them on the top with fork. Do not try to crush all of them just some on the top. Put sugar, mix it and leave it for 20 minutes. Squeeze half of the lemon and add it to the gooseberries. Start cooking on the lowest heat. It will take about 2,5 hours on a very low heat. Mix very often. Remove any skimming foam from the top if it will be noticeable.
Prepare two 10 oz. jars and sterilize it with boiling water. Put hot jam in the jars and close tightly with the lid. This is all what I did. However, boiling water bath can be done, if desired.