It’s June, and you know what that means? Strawberry harvest time! Even if you don’t grow strawberries, you can visit farmer’s markets or u-pick farms, and after you’ve had your fill of fresh strawberries, you can save the harvest by making strawberry jam. This was the very first thing I ever canned, and I bought the strawberries at a roadside stand in Florida more than 20 years ago.
This is a great recipe for getting started with canning jams. It is the old-fashioned recipe that does not use pectin. It has to be cooked longer than a jam with added pectin, and this results in a more concentrated jam. (That’s probably why I love the flavor so much.) By longer, I mean hours rather than minutes, so don’t get this started in the evening after your children have gone to bed. It is simple, and the results are delicious.
Makes 4 pints or 8 half-pints (jelly jars)
- 2 quarts strawberries
- 6 cups sugar
Wash the strawberries and pluck off the greenery. Using a pot that will hold all of the strawberries, add them a few at a time and crush them with a potato masher, and then add sugar. Cook over medium heat and stir until the sugar dissolves. Continue boiling, and stir every 10 minutes or so until it has reached gel stage. Since this will be a few hours, I usually plan something else to keep me in the kitchen (like making cheese or bread) so I don’t run off and forget about the jam.
There are several methods to test for gelling. A candy thermometer is the most scientific approach. The official gelling temperature is 220°F (or eight degrees above the temperature at which water boils at your elevation).
Less scientific but equally accurate is the chilled plate test where you plop a spoonful of jam onto a cold plate and stick it in the refrigerator for a few minutes. If it sets up, it’s jam. If it runs across the plate when you tip it, it could use a little more cooking.
For a beginner, the most challenging method of determining the gel point is the sheeting test. Scoop up a spoonful of jam and tip it. If the jam dribbles off in drops or streams, it’s not done. After it has gelled, it will slide off the spoon in a sheet. The best way to learn this is to do it early in the jam-making process; then you can see how it changes as it gets closer to the gel point.
Don’t sweat the gel point too much. My husband tends to want to get it just right and initially overcooked a couple of batches, which made for a jam so thick it was a challenge to spread on bread. If that happens, the jam makes a great addition to hot oatmeal. On the other hand, I tend to be in a hurry and might decide it is done a little early sometimes, but then I just call it syrup.
After the jam has reached the gel point, it is ready to be canned. Turn off the burner and skim off any white foam that may have formed on top. It’s not harmful, just not attractive. Fill the jars, leaving 1/4-inch headspace. Wipe the rim of each jar with a wet paper towel. Jam or syrup left on the rim increases the chances of seal failure on the lid.
Tighten the lids gently, and process for 10 minutes in a boiling water canner.
If you don’t want this much sugar in your jam, you will need to follow a recipe for low-sugar or sugar-free jam that uses special low-sugar pectin. The sugar in old-fashioned jam helps the gelling process and inhibits the growth of mold and yeast.
Other Canned Fruit Recipes
3 thoughts on “Strawberry jam”
Thanks for this recipe! When you say process for 10 minutes, do you mean hot water canning? Just asking because I'm clueless. :*)
Yes, a boiling water canner, not a pressure canner. The book only has boiling water canner recipes, so I suppose my editor thought it was redundant to add that to every recipe. This recipe got cut because I ran out of room, so I'll add that back in. Thanks for asking!
Thank you! 🙂