Place your strawberries flat on a pan. Use a potato masher to mash them to the consistency you like. I prefer somewhere between a smooth and chunky texture.
Put the mashed berries and water into a pan over a medium flame. Add lemon juice and pectin. Stir well to combine. Bring to a boil, stirring very often.
Boil for 1 minute. Taste and add sugar if needed. Boil for another 2-3 minutes, until jam starts to thicken. You can test it by dropping a spoonful onto a plate. If it is the correct consistency, it will ball up cohesively.
Immediately ladle hot jam into hot, sterilized* 8 oz jars, leaving ¼ inch of space at the top. Put lid and ring on the jar and place it on canning rack, above boiling water.
Once all jars are done, submerge rack, so jars are covered by at least an inch of water. Boil for 10 minutes. Remove and let cool on a rack or a towel, keeping a few inches of space between the jars. Don't touch or examine for 12-24 hours or you might inadvertently break the seal. Once completely cool, you can check to make sure each jar is properly sealed by nudging the edge of the lid. Enjoy, store or share.
Recipe by Mamaguru at http://mamaguru.com/making-groceries-strawberry-jam/