It’s crucial that you sterilize the jars correctly because the basic principle of canning is to kill all the microorganisms that spoil food, then to seal the jar tight to keep them out.
Don’t skimp out on the sugar. You may think that this will make the jam healthier, but it will actually ruin the consistency of the jam.
You can test the consistency of the jelly with a chilled spoon.
Place a softened seal on each jar. A magnetic lid wand will help you get them safely out of the boiling water. To release the seal, set it on a jar and tilt the wand. If you don’t have a lid wand, you can use a small pair of tongs. Screw a clean ring down over the seal and tighten it with snug hand pressure. Don’t tighten so much that you press all the seal material off of the rim.
Wash the jars in cool, soapy water to remove any sticky residue on the outsides. You can remove the rings at this point, since the seals should be holding themselves on securely. Allow the rings and jars to dry thoroughly before replacing the rings, to prevent rust.
