Homemade Strawberry Rhubarb Jam

When springtime rolls around, strawberries and rhubarb are one of the earliest crops we can harvest. They go delightfully well together, as evidenced by this strawberry rhubarb jam recipe. It’s a great way to save some of the flavor of spring!

Plenty of strawberries? Make up a quick batch of this easy strawberry compote, too!

4 jars of strawberry rhubarb jam, no lids.

My dad has two rhubarb plants growing. They started as cuttings from my grandma’s rhubarb plant, meaning this plant is 60 or more years in the making.

It’s one of those crops that require some special consideration about how to use it. Rhubarb by itself is quite sour. Sweetening it is a necessity, as in this rhubarb crisp. Or add it as an extra flavor in baked goods like this rhubarb coffee cake. And then there’s jam!

Easy Strawberry Rhubarb Jam

Combine tart rhubarb with the sweetness of strawberries, and you get deliciously flavorful fruit spread. 

The Handcrafted Pantry

Ready to DIY your pantry with more wholesome ingredients? Check out my ebook, The Handcrafted Pantry! Filled with delicious recipes for some of your favorite condiments, snacks, and toppings, it’s the guide you need to start skipping packaged products and embrace homemade.

strawberries and rhubarb with a jar of jam.

Ingredients

Strawberries Fresh strawberries are listed on the on the Dirty Dozen list put out by the Environmental Working Group, so you might want to opt for the organic berries. Can you use frozen strawberries? Absolutely! 

Rhubarb Fresh rhubarb stalks look much like a reddish colored celery. Find a friend or farmer who can supply you with a pound or more. The leaves are to be avoided.

Sugar Use your favorite brand of granulated cane sugar. I prefer organic.

Pectin – This recipe is made using Pomona’s Universal Pectin. This is the only pectin I use anymore as it allows me to use much less sweetener. The standard pectin brands use an obscene amount of sugar in my opinion, often requiring equal amounts of sugar and fruit! This product uses a low methoxyl method and calls for using two different ingredients, which are included in the box: pectin (the large packet) and calcium powder (the small packet). The dry pectin is mixed with the sweetener before being added to the fruit. The calcium water is added directly to the fruit.

Lower Sugar Jam

I use Pomona’s Universal Pectin exclusively, since it allows me to use much less sweetener. There are a couple of steps when using this brand, but they’re easy steps.

First, you’ll use the calcium powder (in the small packet), and mix 1/2 teaspoon powder with 1/2 cup water. This will result in what we’ll call calcium water. You’ll have more calcium water than you need. Keep the leftovers in the fridge for your next batch of homemade jam. 

You’ll add this calcium water to the strawberries and rhubarb.

The pectin powder (in the large packet) is then combined with the sugar. You want to make sure that it’s thoroughly combined before adding to the cooking berries and rhubarb.

cooking strawberries and rhubarb in a pot.

Preparing the Jam

Start by chopping and cooking the rhubarb until it’s soft. Add the mashed strawberries along with the calcium water and bring to a boil. 

Meanwhile, combine the sugar and pectin thoroughly. Once the fruit mixture is boiling, you’ll add the sugar and stir vigorously to dissolve the pectin. 

Preserving this Strawberry-Rhubarb Jam

My favorite way to preserve homemade jam and jelly is to water bath can it. This means that it becomes a safe shelf stable product that can be stored at room temperature. It’s easy to do, but if you’d prefer, freezing or simply refrigerating this jam is fine, too. 

strawberry rhubarb jam in a pot, with a ladle of the jam above.

Canning Jam

This is often the sticking point for people who have never canned before. It’s something “new” and why is it that we think “new” is difficult?? It’s not! You’ll need special canning jars, lids, and rings (read more about canning equipment here).

jars of strawberry rhubarb jam, before setting lids in place.

Once the jars are filled, you’ll process them in a water bath. What this means is you’ll put the filled and sealed jars of strawberry jam into boiling water and heat them for ten minutes. This assures that the jars will seal well.

You might be able to use a large pot, rather than a special boiling water canner

Remove the hot jars to a towel-covered countertop and allow to cool fully. As they cool, you’ll hear the little “tink” sound of the jars sealing. Store any unsealed jars in the fridge and use those first. (This is unusual, but it does happen once in awhile.)

Remove the ring from each sealed jar, rinse to remove any jam residue, and store (without the ring) in a cool place or the pantry.

Here’s a more detailed look at canning jam and jelly along with a collection of delicious homemade jam recipes.

🍅 Safety First!

Canning is an excellent way to preserve food for the pantry, but there are some important safety considerations to keep in mind. The recipes on this site have been made following safe canning procedures by a certified Master Food Preserver.

4 jars of pink jam, from above, no lids.

Freezing Jam

To make strawberry rhubarb freezer jam, prepare jam as directed, leaving a sufficient headspace for expansion during freezing.

Use your favorite freezer containers or glass jars. Go here for tips on safely freezing in canning jars

Refrigerator Jam

To make strawberry rhubarb refrigerator jam, prepare jam as directed and refrigerate once it has cooled. Use within 2-3 weeks.

Serve this delicious jam spread on toast, as one does, or spoon some over a scoop of vanilla ice cream for dessert.

strawberries and rhubarb with a jar of jam.

jars of strawberry rhubarb jam, before setting lids in place.

Strawberry Rhubarb Jam

The flavor of this easy strawberry rhubarb jam far exceeds what you can pick up in grocery stores. In fact, this particular flavor is hard to find commercially! Consider making a few batches so you can give jars of jam as gifts.
5 from 1 vote
Print Pin Rate
Prep Time: 20 minutes
Cook Time: 30 minutes
Processing Time: 10 minutes
Total Time: 1 hour
Servings: 40 servings
Author: Kris Bordessa, National Geographic author

Ingredients

  • 1 pound rhubarb sliced
  • ½ cup water
  • 2 cups mashed strawberries
  • 1 tablespoon calcium water from Pomona's Pectin package
  • 1 cup sugar
  • 1 tablespoon pectin from Pomona's Pectin package

Instructions

Prepare for Canning

  • Prepare the calcium water: Combine ½ teaspoon calcium powder (from the small packet in the box of Pomona’s pectin) with ½ cup water in a small jar. Screw on a lit and shake until well-combined. You'll have more than you need for this recipe. Store the excess in the refrigerator for use in making additional jam or jelly recipes.
  • Wash the jars you'll use, making sure each is clean and free of nicks in the rim, which could impede sealing.
  • Wash the lids and rings in hot soapy water. (If you're using non-Ball brand lids, prepare as suggested by manufacturer.)
  • Place empty jars in a canning pot or large stock pot with enough water to cover by an inch or two, cover pot, and set on high heat. It can take awhile for the water to heat, so get it started before you begin making the recipe.

Make the jam

  • Combine sliced rhubarb with ½ cup water in a small saucepan. Cook until rhubarb is softened. Use a potato masher or immersion blender to further crush the cooked rhubarb into small pieces if desired.
    1 pound rhubarb, ½ cup water
  • Measure 2 cups of cooked rhubarb into a saucepan with the mashed strawberries. Add calcium water and stir well.
    2 cups mashed strawberries
  • Bring fruit to a boil over medium high heat, stirring occasionally. 
  • Meanwhile, thoroughly combine sugar with the pectin.
    1 cup sugar, 1 tablespoon calcium water
  • When fruit comes to a full boil, slowly add the pectin and sugar mixture, stirring thoroughly for a minute or two to dissolve pectin.
    1 tablespoon pectin

Canning strawberry rhubarb jam

  • Lift hot jars from the canner and drain.
  • Ladle hot jam into half-pint or pint jars to within a quarter inch headspace. (The distance from the top of the jar to the jam.) A canning funnel makes this easy.
  • Use a non-metal tool to remove any visible air bubbles.
  • Wipe the jar rims to remove any jam that may have spilled. A clean rim is essential to a good seal.
  • Set jar lids in place. Screw bands on finger tight.
  • Use a jar lifter to gently submerge jars into the water bath canner. Be sure to place a wire rack in the bottom of the pot to prevent the jars from sitting directly on the bottom. Water should cover the top of the jars by an inch or two. The water will cool somewhat in reaction to the addition of the jars. Return the water to a low boil and then set the timer.
  • Process in a boiling water bath for 10 minutes. For those at a higher altitude, add a minute to the boiling time for every 1,000' above sea level.
  • Check seals. Lids should be solid and pulled down tight. (if they flex and pop, the jar didn’t seal; put unsealed jars in the refrigerator and use those first).
  • Remove rings and wash outsides of jars. Store in a cool, dark place.

Notes

  • This recipe is made using Pomona’s Universal Pectin. This is the only pectin I use anymore as it allows me to use much less sweetener. The standard pectin brands use an obscene amount of sugar in my opinion, often requiring equal amounts of sugar and fruit! This product uses a low methoxyl method and calls for using two different ingredients, which are included in the box: pectin (the large packet) and calcium powder (the small packet).
  • If you prefer a sweeter jam, you can use up to 2 cups sugar.
  • To make strawberry rhubarb refrigerator jam, prepare jam as directed and refrigerate once it has cooled.
  • To make strawberry rhubarb freezer jam, prepare jam as directed leaving a sufficient headspace for expansion during freezing. Use your favorite freezer containers or glass jars. Go here for tips on safely freezing in canning jars.
  • Many water bath canning recipes call for the addition of lemon juice to assure proper acidity levels. Rhubarb is so sour, it's not necessary for this jam recipe. This recipe tests at 3.0 pH, making it safe for the water bath method.
  • Boiling lids or heating above 180°F as once recommended can damage the sealing compound.
  • SOURCE: Adapted from Pomona's Universal Pectin.

Nutrition

Serving: 2tablespoon | Calories: 25kcal | Carbohydrates: 6g | Protein: 0.2g | Fat: 0.1g | Saturated Fat: 0.01g | Polyunsaturated Fat: 0.02g | Monounsaturated Fat: 0.01g | Sodium: 1mg | Potassium: 44mg | Fiber: 0.4g | Sugar: 5g | Vitamin A: 12IU | Vitamin C: 5mg | Calcium: 11mg | Iron: 0.1mg
Did you make this recipe?Mention @attainablesustainable or tag #attainablesustainable!

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About the author: Kris Bordessa is an award-winning National Geographic author and a certified Master Food Preserver. Read more about Kris and how she got started with this site here. If you want to send Kris a quick message, you can get in touch here.

2 comments… add one
  • April Dore Jun 9, 2023 @ 4:00

    Hi. I wanted to make this jam in the small 1.5 oz jars to give as gifts. How long would you have to water bath them for. These are all new jars and lids.

    • Kris Bordessa Oct 10, 2023 @ 12:59

      Reducing the jar size is safe in canning, just follow the processing time as required for the original size. (Don’t do it for less!)

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