Blueberry Jam

In yesterday’s post I offered the world’s easiest blueberry preservation technique- freezing.  I also promised to provide an overview on how to make blueberry jam.  I’m a gal of my word, so as promised, I put together a primer on making and canning blueberry jam.  First, a couple words of caution:


  1. This recipe is specifically for blueberries.  While the principles of canning remain the same if you’re using other fruits, you cannot switch out blueberries for something else in the preparation of the recipe.  If you have other fruit, use a recipe tailored for that fruit so you can maintain the proper levels of acidity and sugar to preserve your jam best. 
  2. Have your mise en place ready to go.  (Repetitively redundant, I know…)  Think of making this like you would  a stir-fry.  If you try to measure things out and run around to find implements you’ll run the risk of ruining it.  This is not a walk-away-and-do-other-things project.
  3. Once you make your own jam you will be very, very bitter if you have to purchase jam at the store.  The flavor and cost of homemade jam will convert you powerfully fast!

Onto business…


Blueberry Jam Primer and Recipe


Ingredients for approximately 6 cups of jam:

  • 4 cups sugar, measured into a mixing bowl
  • 6 cups whole, clean, very fresh blueberries
  • 1 package powdered pectin (not liquid!)


Sugar, blueberries and pectin for jam.



Hardware Needed for Canning 6 Cups of Jam:

  • 1 or 2 extra sterlized half pint jars (just in case you have a bit of extra)
  • Sterilized rings in the proper size for each jar (regular or wide mouth)
  • New lids in the proper size for each jar (regular or wide mouth)
  • Large stainless steel or other non-reactive* stockpot (not pictured below)
  • Long handled wooden or stainless steel spoon (not pictured below)
  • A timer or a clock with a minute hand (not pictured below- and don’t laugh.  I know people who are not in possession of these things on purpose!)

*I’m going to keep using the phrase “non-reactive” during canning season.  Basically, all you need to really know about this is that you should use stainless steel, glass or enamelware.  Anything else (aluminum, etc…) can chemically react to the food and create off-flavors during the process of preserving food.  That is most assuredly to be avoided.


Necessary gear for canning jam.


Helpful Gear (that is not strictly necessary) for Canning Jam:

  • A large boiling water canner
  • Canning tongs
  • Canning funnel
  • Silicone hot mitts
  • Potato Masher
  • Stainless steel or other non-reactive ladle


Boiling water canner, canning tongs and funnel, silicone hot mitts, potato masher and ladle.  Canning made easy!

The Process:


  • Before you start smashing berries and boiling stuff like the witches in Macbeth, you need to have your jars, lids and rims ready to go.


Have your jars prepared so that when the jam is done you can fill them immediately!

  • Pour blueberries into a large bowl.  Please, please don’t use a small bowl:  You’ll be chasing blueberries around the countertop and floor if you do.  Using a potato masher or the bottom of a drinking glass or jar, smash the daylights out of the blueberries.  If you’re in a hurry, you can pulse the berries in a food processor- but don’t purée them.  Jam is supposed to have bits of fruit in it!


How your berries look while mashing.

How your berries look when ready to continue to the next step… Smashing, no?


  • Pour your 4 cups of smashed blueberries- you did measure again, didn’t you?- into a large non-reactive stockpot.
  • Sprinkle powdered pectin over the surface of the blueberries.


Yes, I said sprinkle but this picture shows me dumping the pectin.  I am not so coordinated that I can gracefully sprinkle pectin and take a picture simultaneously. 

  • Stir the pectin into the fruit thoroughly.



If you dump it in, don’t panic.  You’ll just have to do more stirring.

  • Bring the mixture to a boil over high heat, stirring constantly.  Do not walk away.  Burned blueberries smell very, very bad.
  • When mixture reaches a full rolling boil*, add the sugar all at once and quickly stir it in completely.

*A full rolling boil is when it does not stop boiling even when stirred- which you’re supposed to be doing anyway, right?


Do not step away from the pan.  I repeat.  Do not step away from the pan.  Keep stirring!


  • Bring back to a full rolling boil.  As soon as it reaches the full boil, begin timing.  Allow to boil hard for EXACTLY 1 MINUTE!  Do not overcook.  Kill the heat as soon as the timer goes off!
  • As soon as you have removed the stockpot from the heat, begin ladling (or scooping by whatever sterile means are at your disposal) the jam into the jars.  And for the love of all that is holy- this stuff is HOT and it HURTS if you splash it on your bare skin so be careful!
  • Using a clean, damp paper towel, wipe the rims of the jars clean.  You don’t want gunk of the rims because that increases the risk of spoilage.



These jars are filled, wiped clean and ready to be lidded and processed.

  • Place a lid, seal side down, on top of each clean jar.  Add a ring and screw it into place.  Don’t overtighten! 
  • Put all jars into the empty canner (or other deep pot with a fitted lid) and fill with water to completely cover all jars.
  • Place lid on pot and bring to a full rolling boil.  When water reaches a full rolling boil*, start timer for 10 minutes**. 

*Again with the full rolling boil.  It’s important!


Doesn’t this look like a Macbeth moment?  You know- “When the hurly burly’s done.  When the battle’s lost and won,” and whatnot?

**If you’re using a larger size jar, adjust processing time accordingly.  Quarts process for 15 minutes.

  • When jars have processed for the appropriate amount of time, carefully remove all jars to a cooling rack.


Can you tell I have wicked hard water?


  • All that remains is to remove the rings carefully, wipe down the jars with a damp cloth, and check your seals.
  • If you have any seals that failed, simply put those jars into the fridge to use right away.  All sealed jars can be stored in a single layer on a shelf without their rings!


Voila y voila!  Blueberry jam! 


I hope I’ve convinced you that it’s worth your time and effort to make this.  …But just in case I haven’t convinced you yet, here are a couple other great reasons to try it:

  • It goes without saying that this jam is out of this world on toast but don’t stop there.  Put a couple spoonfuls in a bowl and mash about with a fork.  Then spoon that softened jam over vanilla ice cream (are you sensing the ice-cream-for-life-theme here?) 
  • Throw a quarter cup into a blender with plain yogurt, frozen berries and purée for a fantastic blueberry smoothie. 
  • Glaze roasted pork with softened blueberry jam.   


You can do so much with this stuff.  Get creative!


  1. Daina says

    I usually start my water bath on the heat while I’m making whatever it is I’m canning, so that the water is almost or already at a boil when I put my jars in. Should I not be doing this? Also – I have wicked hard water too, but if you pour in a few tablespoons of vinegar into your water bath, it keeps the jars from collecting the hard water stuff on the outside.


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