Wash the berries carefully removing all the stems and soft berries that you wouldn’t eat. (The berries you wouldn’t eat now will spoil the whole jam). Check where stems come off make sure no white stuff is in that center that may be mold.
Put the berries in a large pot at least 4 to 5 times taller than the berries in the bottom.
Add the pectin, lemon juice and about ½ to 1 cup water. The water just helps it from scorching in the very beginning.
Bring it to a rolling boil you cannot stir down. Put 2 heavy metal large cooking spoons in the freezer NOW or before you start.
Carefully add all the sugar and stir quickly. I say carefully because when it pops up it will burn you, I know from experience! LOL!
Cook jam until another full rolling boil. Then cook for 5 minutes longer. I use a good candy thermometer to check and make sure it is 220 degrees and stays there for about 5 minutes. Add the vanilla now even if you are going to have to cook it longer it will be ok.
Add the vanilla now. Even if have to cook it longer.
Best way to make sure is to get your spoon out of the freezer add 1 tablespoon of the hot jam and wait 30 seconds. Now take your finger and swipe it across the jam. It should stay apart leaving a streak down the middle where your finger swiped the jam.
Now ladle into hot jars and process at least 10 minutes I usually process 15 minutes. Please look in the sure jell box for more instructions on canning. This is the basic recipe.
About the foam, in this jam it will almost all go away by the time it is ready to put in the jars. If it doesn’t just skim off the water parts and put in a dish. You can spread it on crackers or toast if you want, it is perfectly safe to eat. If you have a ton of foam at the end you can add ½ teaspoon or margarine and cook about a minute longer.
I always let my jam set for about 10 to 20 minutes before putting it in the jars. If you have foam that also will help with the jam absorbing the foam.