Strawberry Jam for Canning

1. Stage

Stem the strawberries: Rinse the strawberries and trim off any mushy parts. Then stem the berries, being careful to remove just the green leaves and stems but not the tops of the berries themselves. The pale tops of the berries are high in pectin and will help your jam set.

2. Stage

Crush the berries with the sugar: In a non-reactive (stainless steel or enamel) pot that can hold at least 5 quarts (larger is better), combine the berries, sugar, and lemon juice. Toss to combine. Crush with a potato masher until you have some juicy smashed berries, while others remain whole. You may need to put some muscle into it. It’s cathartic!

3. Stage

Refrigerate the pot overnight or up to 3 days: Cover the pot with the crushed strawberries and sugar and refrigerate it for at least 8 hours, and up to 3 days. Don’t skip this step if you are smart! Breaking things up into a few days leads to better jam and lets you clean up in steps, so you don’t get overwhelmed.

4. Stage

Prepare the water bath and jars: When it’s time to cook the jam, first get your canning equipment ready. Set up a water bath canner with a canning rack in the bottom. Add 6 half-pint jars and enough water to cover the jars by at least an inch. Heat over high heat as you continue with the recipe. Wash the lids and bands in hot, soapy water. Have your tools ready on the counter near the canner: a ladle, a sturdy cooking spoon, a canning funnel, canning tongs, a clean and sturdy cloth towel, and two clean paper towels or cloth towels.    Put a plate (preferably white or light-colored for better contrast) in the freezer for the plate test you’ll do later on to help determine if your jam is set.

5. Stage

Start cooking the jam: Bring the pot from the fridge. Uncover, give it a good stir, and set it on a burner over medium-high heat. It’ll probably be really soupy, but that’s okay. Because it’s cold, it’ll take up to 10 minutes for it to come to a boil. No need to stir yet.

6. Stage

Continue cooking and stirring for 30 to 60 minutes, maybe even longer: As the jam cooks, it will slowly transform. Give it a stir every few minutes and pay attention to how it looks and sounds. Early in the cooking, the strawberries will keep their shape and the liquid in the pot will be quite watery. Foamy scum will rise in the center and/or sides of the pot. You can ignore it for now. As the jam continues cooking, adjust the heat so it maintains a boil that’s lively, but not out of control. The bubbles will eventually get bigger and thicker. They’ll make sticky popping sounds, and the pot will resemble jammy lava rather than soupy berries. The strawberries will fall apart. Instead of falling from the spoon in watery drips, the jam should roll off the spoon in sticky blorps that cling a bit. When these things happen, you may be nearly done; it’s time for a plate test. If not, keep on cooking.  It can take between 30 and 60 minutes for the jam to reach the point when it gels, or turns jammy. Be patient. My jams usually take a little longer than 60 minutes to get there.

7. Stage

Do a plate test: When you suspect the jam is set, get your chilled plate from the freezer. Put a dollop of jam on the plate and let it sit for 1 to 2 minutes.  If the dollop runs and spreads out thinly, the jam isn’t ready. Keep on simmering. If the dollop mounds up a bit and wrinkles slightly when you touch it with your fingertip, it’s ready to can.

8. Stage

Fill the jars: Reduce the heat to the lowest setting possible. Skim off the last of the foamy scum from the ridge of the pot. Remove the jars from the canner with jar lifters. Ladle the hot jam into the hot jars, leaving 1/4-inch headspace (that’s the gap between the top of the jam and the rim of the jar). If there’s any jam on the rims of the jars, wipe them off first with a clean damp towel, and then a clean dry towel.  Place the lids on the jars, then screw the bands on so they’re just fingertip-tight. Any jar that’s only halfway filled you can skip processing in the water bath; just refrigerate and use it first.

9. Stage

Process the jars in the water bath: Using jar lifters, lower the jars into the water bath. Make sure the water is at least 1 inch over the tops of the jars. If not, add more water. Once the water reaches a full rolling boil, set a timer for 10 minutes. When the timer is up, use the jar lifters to pluck the jars from the water bath and set them on a towel on the counter.

10. Stage

Check for the seal: As the jars cool, the tops should seal. Sometimes this happens right away, with an audible pop. Sometimes they make no sound at all and take up to 15 minutes, or even a few hours. You can tell a jar is sealed when you tap firmly on the lid and hear a dull thump. Lids that aren’t sealed will make a metallic ping.

11. Stage

Label, date, and store: Let the sealed jars cool completely. Don’t you feel proud of yourself now? Label and date your splendid jam for posterity!  Sealed jars will keep for at least several years, but are best consumed within 1 year.  Refrigerate or freeze any unsealed jars. Did you love this recipe? Give us some stars below!