As a child I always thought of canning as that dangerous old-fashioned way to preserve food that was no longer necessary in the era of the modern grocery store, but now I'm a bit sad that I never learned to can while growing up. My grandmother used to can, but she never taught her children, and by the time I was old enough to notice, she was no longer canning. But this winter I bought a Ball home canning kit, and I'm really excited to give it a go this year, especially with jams and pickles. To get myself started, a few weeks back, I attended the introductory canning class run by Emily of Preserving Traditions in the Pittsfield Grange.
One of the most notable things I learned is that strawberry jam does not get botulism. It's a risk for low-acid foods, but not high acid foods like strawberries. What a relief to know that my top canning fear is not relevant for strawberry jam! The jam can still go bad, but it's pretty obvious when that happens — the seal is broken, or when you open the jar it smells fermented or looks moldy. I think that makes strawberry jam an excellent choice for a beginning canner.
I'm not an expert on canning, so I'm not going to describe the whole process less I leave out something important. Please consult an expert or a time-tested trusted source such as Ball Blue Book of Preserving, which will tell you how to water bath can and which foods are safe for water bath canning.
That said, you don't need to actually do the whole canning process to enjoy homemade strawberry jam. You can still make the jam, but refrigerate or freeze it.
Emily prefers to not use pectin for her strawberry jam. Pectin is what makes jams and jellies gel, and strawberries naturally contain a lot of pectin. Adding pectin means that you can guarantee that your jam will gel, but it also means you'll be using a lot more sugar, which will make the jam more sugary and less intense on the strawberries. (EDITED to add: other canning experts say it is the other way around. That is, you can use less sugar when you use pectin. Also, you don't have to cook fruit down as much when you use pectin.)
3 cuts strawberries, cut into bite-sized pieces
1 cup sugar
2 Tbs lemon juice (bottled is better because of its consistent acidity)
Put a few small plates in your freezer. They'll be used for testing how the jam is gelling.
Stirring constantly, bring all ingredients to a boil in a large pot over medium flame. Once it starts boiling (it'll foam a lot), start timing. After, about 10-12 minutes, test your jam for gelling: take one of the cold plates from the freezer and drip just a 1/4 tsp of so of jam on the plate. Let the plate sit for 30 seconds, then hold the plate vertical. When the jam is properly jelled, the drop will ooze slowly down the plate, clinging like, well, jam. :-) If the jam is running, continue to cook and test again in a few minutes using a cold plate.
When the jam is jelled, you can eat it as is (pour into a sterilized jar and refrigerate. Will keep for four to six months in the fridge without canning) or can it in a hot water bath for long-term non-refrigerated storage. (Refrigerate once opened.)
Preserving Traditions is a local club focused on sharing knowledge on how to preserve our own food and on supporting our local "food shed." On July 12, they are holding a cherry pie class, and in August, you can learn how to make pickles. Check out their calendar of upcoming events.
Emily showing how to properly and safely pick up a hot mason jar.