How do I make rhubarb jam?

Rhubarb is extremely tart but brings little body of its own, so the tested rhubarb jams pair it with added pectin and usually with a second fruit. The most common is strawberry-rhubarb jam: 2 cups crushed strawberries, 2 cups chopped rhubarb, one package of powdered pectin, 1/4 cup lemon juice and 5 1/2 cups sugar, for about 6 half-pints, from the Ball Blue Book as printed by Oregon State University Extension. For a rhubarb-forward jam there is a tested rhubarb-orange version, and USDA has a strawberry-rhubarb jelly. Use the stalks only; rhubarb leaves are poisonous. This page gives each recipe and the processing time each one needs.

Four tested ways to put rhubarb in a jar

Pick one row and follow it exactly.

Why rhubarb needs a partner

Oregon State describes rhubarb's flavor as "extremely tart" [1]. Tartness helps a gel, but a jam also needs pectin, and none of the tested rhubarb jams relies on rhubarb's own: every one adds commercial pectin [1] [2] [4] [5]. Rhubarb is a federal Group I fruit [6], so a rhubarb jam sold under the standard name needs at least 47 parts fruit to 55 parts sugar; in a blend, the rules for combining fruits apply, explained on how much fruit the law requires.

Strawberry-rhubarb jam with powdered pectin

As printed by Oregon State University Extension in Preserving Rhubarb, from the Ball Blue Book [1].

1. Combine 2 cups crushed strawberries, 2 cups chopped rhubarb, one package powdered pectin and 1/4 cup lemon juice in a large saucepan. (Have your canner, jars and lids ready first.)
2. Bring to a boil over high heat.
3. Add 5 1/2 cups sugar, stirring until dissolved, and return to a rolling boil.
4. Boil hard 1 minute, stirring constantly. Remove from heat and skim foam if needed.
5. Ladle hot jam into hot jars, leaving 1/4 inch headspace. Adjust two-piece caps.
6. Process 10 minutes in a boiling water canner. Turn off the heat, remove the canner lid and wait 5 minutes before removing jars.
7. Store the jam in a cool, dry, dark place for best quality.

Oregon State gives no altitude adjustment for this jam; its altitude table is for plain canned rhubarb [1]. Use the band chart below.

The UC Master Food Preserver printing of the same Ball recipe calls for 6 tablespoons of Ball Classic Pectin in place of "one package," 1 1/2 to 2 pounds of strawberries and 3 to 6 stalks of rhubarb, chopped in 1/2 inch pieces [3]. If you use bulk pectin, measure it by the tablespoon as UC gives it.

Rhubarb-orange jam

From the UC Master Food Preserver Program, citing the Ball Blue Book Guide to Preserving (2014) [2].

1. Wash the rhubarb and oranges under cold running water and drain. Trim the rhubarb, removing leafy tops and root ends, and chop it into 1/2 inch pieces. Halve and seed the oranges and juice them to measure 1 cup. Cut thin slivers from the peel of half an orange, removing the white pith.
2. Sterilize the canning jars by boiling them 10 minutes at altitudes under 1,000 feet, adding 1 minute for each additional 1,000 feet.
3. Combine the rhubarb, orange juice and peel in a large saucepan. Cover and simmer about 3 minutes, until the rhubarb is tender.
4. Stir in 6 tablespoons Ball Classic Pectin and bring to a boil over medium-high heat.
5. Add 6 cups sugar and stir until dissolved. Bring to a full rolling boil and boil hard 1 minute, stirring constantly. Remove from heat and skim foam if necessary.
6. Ladle into hot, sterile jars with 1/4 inch headspace, remove air bubbles, wipe the rims with a dampened clean paper towel and adjust two-piece metal canning lids.
7. Process 10 minutes in a boiling-water or atmospheric steam canner, adjusting for altitude as below. The UC sheet adds that if you use unsterile jars, the filled jars are processed for 10 minutes [2].

USDA strawberry-rhubarb jelly

From USDA's Guide 7, also published by NCHFP [4] [7]. Wash the rhubarb, cut it in 1 inch pieces and blend or grind it. Wash, stem and crush the strawberries, one layer at a time, in a saucepan. Place both fruits in a jelly bag or double layer of cheesecloth and gently squeeze out the juice, as the recipe directs [4] [7]. (Guide 7's general jelly directions note that pressing or squeezing a bag clouds jelly; the recipe's word is gently.) Measure 3 1/2 cups juice into a large saucepan, add the butter if using (1/2 teaspoon, optional, to reduce foaming) and the 6 cups sugar, mixing them thoroughly into the juice, and bring to a boil over high heat, stirring constantly. Immediately stir in the 6 ounces of liquid pectin, bring to a full rolling boil, and boil hard 1 minute, stirring constantly. Remove from heat, quickly skim off foam, and fill sterile jars with 1/4 inch headspace. Wipe the rims with a dampened clean paper towel, adjust lids and process.

The jelly specifies red rhubarb stalks [4]. Rhubarb stalks range from pink and light red (hothouse) to dark red or green (field grown) [1], so for a red jelly, choose red stalks.

Processing: two systems, one rule

The rhubarb recipes above come from two processing systems, and you use the chart that matches your recipe.

USDA strawberry-rhubarb jelly uses USDA's sterilized-jar chart [4]:

The Ball-derived jams (OSU and UC) start at 10 minutes [1] [2]. A 10 minute process sterilizes the jars during processing, so these do not need pre-sterilized jars [8]. For altitude, NCHFP says to add "any altitude adjustments" to a 10 minute process [8], and this book uses the band steps published by South Dakota State University Extension, which cites the 2016 Ball book [9]:

The UC handouts give a different altitude rule for the same recipes: add 1 minute for each 1,000 feet above sea level [2] [3]. At 2,700 feet that gives about 13 minutes against the band chart's 15. This book follows the band chart because it agrees with every published band step and is never the shorter of the two; the full reasoning is on how long to process jam, and what altitude changes in jam making is on how altitude changes jam making.

Rhubarb without canning

Oregon State's rhubarb-raspberry freezer jam is 6 cups finely chopped rhubarb, 1/4 cup water, 3 1/2 cups sugar and one 3 ounce package of raspberry gelatin: bring the rhubarb, water and sugar to a boil, reduce to medium heat and cook covered until the rhubarb is tender, simmer uncovered 12 to 15 minutes, stir in the gelatin until dissolved, cool, package in freezer containers, and freeze [1]. It is a freezer product, never processed or kept on the shelf. University of Wisconsin Extension's strawberry-rhubarb freezer jams and the general method are on how to make freezer jam.

Stalks only

University of Wisconsin Extension says to use rhubarb stalks only, because the leaves are poisonous [5]. Oregon State's directions say to trim off the leaves [1]. Cut them off in the garden and discard them.

Selling rhubarb products

Penn State's Food for Profit sheet for commercial jam makers lists rhubarb as a low-acid ingredient, and if you sell, you should know what it says. Jams are exempt from the federal acidified foods regulation, it says, "unless they contain significant amounts of low-acid ingredients such as peppers, rhubarb, tomatoes, raisins, figs, nuts, bacon, or spices and herbs," and it strongly advises processors of non-standard jams and jellies that contain low-acid ingredients to use a pH meter to make sure the finished product is well below pH 4.6 [10]. It gives no pH for rhubarb. None of the other sources on this page calls rhubarb low in acid; Oregon State describes its flavor as extremely tart [1].

How much this matters depends on what you sell:

Penn State does not explain why it lists rhubarb, and this page does not guess. Read the listing as a reason to measure your own product; Penn State does not say rhubarb jam is unsafe. How to take a reading, and when one is required, is on measuring pH, and when you need to.

Planning the rhubarb season

Rhubarb and strawberries do not always ripen together. Oregon State's freezer jam allows fresh or frozen rhubarb [1]; the canned recipes above do not say whether frozen rhubarb was tested, so use fresh stalks for those or ask your county extension office. Planning fruit across the year is on a year of fruit, and more strawberry recipes are on strawberry jam.

References

1. Oregon State University Extension, Preserving Rhubarb (SP 50-882), rev. June 2015. https://www.ccfruitandnuts.ucanr.edu/sites/default/files/2020-12/340439.pdf
2. UC Master Food Preserver Program, Rhubarb: Preserve It! (Rhubarb-Orange Jam, from the Ball Blue Book Guide to Preserving, 2014), undated. https://ccfruitandnuts.ucanr.edu/sites/default/files/2022-10/374860.pdf
3. UC Master Food Preserver Program, Rhubarb: Preserve It! (Rhubarb-Strawberry Jam, from the Ball Blue Book Guide to Preserving, 2014), undated. https://www.ccfruitandnuts.ucanr.edu/sites/default/files/2020-09/335063.pdf
4. USDA, Complete Guide to Home Canning, Guide 7: Preparing and Canning Jams and Jellies (Strawberry-Rhubarb Jelly), rev. 2015. https://nchfp.uga.edu/papers/guide/GUIDE07_HomeCan_rev0715.pdf
5. University of Wisconsin Extension, Ingham, Making Jams, Jellies & Fruit Preserves (B2909), undated. https://iowa.extension.wisc.edu/files/2021/08/Making-Jams-Jellies-Fruit-Preserves-B2909.pdf
6. U.S. Code of Federal Regulations, 21 CFR 150.160, Canned fruit preserves and jams (Cornell LII text, current). https://www.law.cornell.edu/cfr/text/21/150.160
7. National Center for Home Food Preservation, Strawberry-Rhubarb Jelly with Liquid Pectin, accessed October 2026. https://nchfp.uga.edu/how/make-jam-jelly/jellies/strawberry-rhubarb-jelly-pectin/
8. National Center for Home Food Preservation, Do I Need to Pre-Sterilize My Jars before Canning?, May 21, 2014. https://nchfp.uga.edu/blog/do-i-need-to-pre-sterilize-my-jars-before-canning
9. South Dakota State University Extension, Kleine and Botzet, A Guide to Water Bath Canning (P-00255), 2022. https://extension.sdstate.edu/sites/default/files/2022-10/P-00255-v2.pdf
10. Penn State Extension, LaBorde, Food for Profit: Commercial Production of Jams, Jellies, and Fruit Butters, updated May 24, 2024. https://extension.psu.edu/food-for-profit-commercial-production-of-jams-jellies-and-fruit-butters
11. Code of Federal Regulations, 21 CFR 114.3, Definitions (Cornell LII), current. https://www.law.cornell.edu/cfr/text/21/114.3