Start to Finish: 4 hours, 30 minutes
Servings: 3 cups of jam
Jam makers add powdered pectin to help their preserves set up more quickly. Pectin also creates a jam with a uniform consistency and with a fresher, less “cooked” taste. Pectin is naturally found within plants’ cell walls and can help preserve fruits’ natural color as it cooks into a jam, but naysayers feel commercially produced pectins lead to jams with a gelatinous texture that often contain too much sugar to encourage the pectin to set up.
Strawberries don’t have a lot of natural pectin, so jams made from fresh berries usually do contain the commercial product. You can easily make a strawberry jam without the additive if you’re willing to put in just a little extra cooking time and work. The jam may be slightly runnier than one that uses pectin, but by cooking down the berries’ juices, you will still come out with a satisfactorily spreadable preserve.
- 4 cups hulled, quartered strawberries
- 2 cups white, granulated sugar
- 2 tablespoons of freshly squeezed lemon juice
Directions for the Jam
Mash the berries slightly and place into a large, non-aluminum pot. Pour the sugar over the top and allow to sit for 3 to 4 hours; the berries’ natural juices will start to release.
Place the pot over medium heat and bring to a boil, stirring constantly to prevent the mixture from burning and to ensure all the sugar dissolves. Remove from the heat and strain the mixture through a sieve into a large bowl. Set the strained berries aside and return the liquid back to the pot and add the lemon juice. Bring the mixture back up to a boil over medium to high heat. Boil until an inserted candy thermometer reads about 220 degrees Fahrenheit, which is just below thread stage — the binding point for fruit pastes.
Stir the cooked berries back in and remove from the heat. Place the jam into canning jars and follow manufacturer’s instructions for sealing. Alternatively, pour into jars and refrigerate for up to 4 months without canning.
As the berries and sugar come up to a boil, a foam sometimes appears on the surface. This foam is completely harmless — just a result of air bubbles that form as the mixture comes up to temperature — but could may slightly compromise the intensity of the jam’s flavor. Lightly skim it off the top with a ladle or heavy spoon if you desire.
Before you place the jam into jars, you can let the mixture rest for about five minutes. This discourages the berries from floating to the top of the jars during storage.
Use slightly under-ripe strawberries as they will benefit from the longer cooking time required to make a quality jam. For seedless jam, process the mashed berries through a food mill before cooking them with the sugar.
Fresh strawberries are often sold in quarts. Figure each quart contains about 4 cups, according to Fine Cooking.
References and ResourcesPickYourOwn.org: How to Make Old-Fashioned Strawberry Jam
The Kitchn: The Point of Pectin
The Kitchn: Canning Basics