Amanda & Merrill

Wild Maine Blueberry Jam/Canning 101

September  1, 2009

- Merrill

Canning is one kitchen activity that can intimidate even the most confident cook. The truth is, it's dead simple. Every August I make jars and jars of wild blueberry jam at my parents' house in Maine, and every Christmas I know exactly what I'm giving out as presents. The best part? It takes all of an hour to make the jam, and both the ingredients and equipment couldn't be simpler.

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Here are a few tips you may find useful if you're canning for the first time:

• Make sure you have a ladle (metal or plastic), a wide-mouthed funnel, a set of tongs with strong grippers, a large pot or Dutch oven and a rack that will fit inside it, sitting at least 1 inch above the bottom.

• You can reuse jars, but make sure you buy new lids and bands each time you make preserves, or they will not seal properly.

• Run your jars through the dishwasher to both clean and sterilize them right before you start your preserves. Do not remove the jars from the dishwasher until you are ready to fill them. Sterilize all other equipment (lids, bands, ladle and funnel) by putting them in a large saucepan and covering them with boiling water 15 to 20 minutes before you start filling your jars.

• If you are canning anything with low-acidity (vegetables, starches, meat), you must use a pressure canner. If however, you are canning high-acid foods (jams, jellies, most fruits), you can use the water bath processing method (see recipe below). Although some will swear that all you need is hot jam and hot jars, processing in a water bath takes only a few minutes and assures that your preserves will keep safely.

• If you have any further questions about safe canning procedures, this is a helpful site.

Wild Maine Blueberry Jam

Makes 7 to 8 cups of jam

  • 6 cups crushed blueberries from about 2 quarts berries (slightly underripe berries work best)
  • 6 cups sugar
  • 1/4 teaspoon ground cinnamon
  • pinch of salt
  • juice of half a lemon

1. Combine the berries and sugar in a large, heavy pot over high heat. Cook, stirring frequently, until the berries have released a lot of juice and have just begun to simmer.

2. Stir in the cinnamon, salt and lemon juice and return to a gentle, rolling boil. Boil the jam for about 40 minutes, stirring frequently, until it is quite thick and a small dollop spooned onto a plate and set aside to cool for a minute does not run when you tip the plate to one side.

3. While the jam is cooking, run 8 one-cup jam jars through the dishwasher (a short cycle will do) and using a large saucepan, cover 8 new lids, 8 bands, a ladle and a wide-mouthed funnel with boiling water. Fill a large Dutch oven or soup pot two thirds full with water and place a rack that is at least one inch high in the bottom of the pot. Bring the water to a simmer and then turn off the heat.

4. Ladle the jam into the hot jars using the funnel, wipe the rims and seams of the jars with a damp paper towel and screw on the lids (do not tighten them completely). Using tongs with a good grip and being very careful, gently lower the jars into the pot of hot water, resting them on the rack. Do not allow the jars to touch each other or the sides of the pot. The water level should be at least 1 1/2 inches above the tops of the jars. If it is not, add some boiling water.

5. Bring the water in the pot to a gentle boil, and simmer to process the jars for 10 minutes. Carefully remove the jars and turn them upside down on the counter. Leave to cool for 12 to 24 hours before turning over and tightening the lids. At some point, you will hear the lids pop, which means they are sealed properly. To make sure all of the lids are sealed, push down on the center of each. If the lid pops back up, the jar isn't sealed; you should refrigerate and eat any jam in unsealed jars within a couple of weeks. Properly sealed jars will keep in a cool, dry place for several months.
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A New Way to Dinner, co-authored by Food52's founders Amanda Hesser and Merrill Stubbs, is an indispensable playbook for stress-free meal-planning (hint: cook foundational dishes on the weekend and mix and match ‘em through the week).

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Ashley May 11, 2018
Hi. I have a ton of frozen wild blueberries. Is there a way I could use them for the jam?
lisina July 24, 2013
if i were to reduce the amount of sugar, would that interfere with how well the jam keeps? (sorry if that's a dumb question--i'm new to canning!)
MrsWheelbarrow July 24, 2013
Altering canning recipes is never recommended. The ratio of sugar to fruit, as well as the use of lemon juice, all contribute to achieving the correct set. Less sugar will surely play with the set and certainly will affect shelf stability. Look for low sugar recipes as an alternative. Low sugar pectin is available at most grocery stores - check out the recipes included in the box.
lisina July 24, 2013
ok, so it's not as if you could just jar anything of jammy consistency that you cook on the stove? the balance of preservatives (natural or otherwise) really comes into play?
Kelsey B. September 4, 2009
I went to college in Maine and can still taste the blueberries I enjoyed there. I love canning and can't wait to try this recipe - I give away homemade jam as my Christmas gifts, too!
Sandy S. September 1, 2009
Blueberry jam from fresh wild Maine blueberries . . . now that's a present that says "I love you"! My all-time favorite jam!
Merrill S. September 2, 2009
We ate some this morning on toast!
MrsWheelbarrow September 1, 2009
I agree with Ellen. I always remove the bands before storing. Several reasons - first, it's the perfect time/way to check the seals. Also, if you have pickles or tomatoes, especially, go bad, the jars won't explode, the lids will just lift off and the mess will pour down the sides. Much better than picking pieces of glass out of the carpet. If this sounds like the voice of experience....
Amanda H. September 4, 2009
I never considered this -- thanks for the tip.
Ellen September 1, 2009
New bands each time you can? I buy new lids, natch, but reuse bands until they appear to have any rust or are bent, or otherwise damaged. My tip for preserving the bands is to remove them from the filled hars before storing the food, so they don't get all rusty.
Merrill S. September 2, 2009
Sorry, yes, I meant new lids but not new bands. Thanks for catching that!