I love strawberry jam – there’s nothing quite like capturing the flavor of strawberries as they are just perfect, sweet, tart, and a little crisp. I buy strawberries locally in season at their peak ripeness because seasonal local flavors are best! It is more cost effective to buy in large quantity, so I usually try to process many fruits & veg in one big day. Then we enjoy all year long! Below is a blanc manger Jake made topped with some of the fresh jam.
While I have a big preference for organic produce, this year I didn’t buy certified organic produce. I was happy to buy locally from Knopp’s Farm in Federalsburg, Maryland at the Baltimore Farmer’s market! In early May, as you may remember, there was a long, multi week period of cold and rain, and our local strawberry crop really suffered. I decided I would rather support a local farmer than an exploitative agribusiness.
Below I’ve listed a recipe for canning 12 quarts of strawberries, which is quite a bit! For me this yielded 12 pints of finished jam, which ideally about how much strawberry jam Jake and I will go through in a year. Plus, we can give away a few for gifts, which I usually do. You can use these same ratios for preparing and canning any straightforward berry jam made of raspberries, blackberries, and blueberries, or a mix!
Post your questions and feedback in the comment section! For more information on canning jams and jellies in general, check out the USDA Jam & Jelly canning guide. This goes into a lot of depth on this subject and it is a great resource.
- 12 quarts strawberries (about 14 pounds)
- 20 cups cane or turbinado sugar
- Juice of 2 lemons
- Optional additions
- 2 cups red wine, hard cider, or ginger beer + 1 additional cup sugar
- 2-3 tbsp lavender flowers
- 2-4 tbsp red chili flakes
- 4-6 cups diced and cooked rhubarb
- 12-16 pint jars or 24-32 half-pint jars with two piece lids and bands (Ball or Kerr jars)
- Large, sturdy pot for canning that can hold jars. I use a 10 gallon stainless steel pot.
- Not necessary, but nice: a candy thermometer, canning rack, and canning tongs
- Put the strawberries in a colander and rinse, then drain, in batches.
- Core strawberries to remove the stems and leaves.
- In a large, wide sauce pot, add strawberries and crush with your hands or a potato masher one layer at a time. I use a 20 quart stainless steel stockpot for making jam, the diameter is about 14 inches.
- Add the sugar to the pot. Don’t skimp on sugar – I always try to reduce sugar, but it is necessary to get the jam to jell. Add lemon and optional additional liquids and sugar now as well. Stir to combine.
- On a stove or outdoor burner, boil the fruit mixture. Stir frequently to dissolve the sugar and so that the jam won’t burn on the bottom.
- Once the jam is boiling, cook with a rapid boil for 20 minutes or until the mixture reaches 220° F. I use a candy thermometer to test the temperature in several places, but you can also use a sheet test if you don’t own a thermometer. As mixture thickens, stir frequently to prevent sticking. Once you’ve reached 220°F, remove the jam from heat and skim foam if necessary.
- Meanwhile, in a large canning or other sturdy pot, place your empty, lidless jars in the pot on a canning rack. Fill the pot with enough water to cover and fill the jars with at least 1 inch of water above the jars. Bring the water to a simmer on an indoor or outdoor burner. Using canning tongs remove hot jars and drain hot water back into canning pot. Rinse the lids and bands in warm water.
- Ladle hot jam into hot jars, leaving 1/4-inch headspace (distance from the top of the jar to the top of the filling). Wipe the rim of the jars to clean away excess jam. Adjust two piece caps onto the jars.
- Bring the large pot of water to a boil and place jars into the water bath. When the water resumes boiling, let jars be processed: pints boil for 15 minutes, half pints for 10 minutes.
- Remove jars and let cool – you should hear the lids “pop” shortly after taking them out. Store in a cool, dark area and enjoy for months to come on muffins, pancakes, toast and more!
If your jam didn’t set:
- Wait 24 hours after canning. Pectins can take this long to set, so don’t be alarmed just yet!
- If it really didn’t set, pour out the jam back into a jam pot and reboil to 220°F. Use a new lids, but same bands and jars are fine to reuse. When you refill the jars with jam make sure to wipe the rim before adjusting the lids on. Reprocess for the same amount of time.
If your jam burned on the bottom:
- Still can the rest! It probably tastes fine! Next time make sure to stir frequently and watch your pot. Use steel wool to scour your stainless steel pots.