Rhubarb jam is incredibly simple to make at home, and all you really need is rhubarb and sugar.
When you make straight rhubarb jam without strawberries, ginger or anything else, you can really taste the rhubarb flavor without any distractions.
Rhubarb is only around for a short time in the spring, but when the plants start producing it’s easy to get buried in fresh rhubarb stalks. I make strawberry rhubarb pie of course, and I’ve recently fallen in love with this Amish Rhubarb Custard Pie. Then I make a bit of strawberry rhubarb jam to send off to family, and a big batch of rhubarb wine to cool us on hot summer afternoons.
After all that, I still have roughly a wheelbarrow full of fresh rhubarb, and it’s time to preserve it in a simple rhubarb jam. There’s something about plain rhubarb jam that helps get me through our long Vermont winters, reminding me that spring will come again, and with it our rhubarb crop.
There are a number of ways to make rhubarb jam, both with and without pectin. It just depends on how firm you like your jam to set.
Regardless of the rhubarb jam recipe you use, it’s best to start by macerating the sliced rhubarb in a bit of sugar for at least an hour (or overnight). The sugar draws out the liquid from the rhubarb and will allow you to cook the rhubarb jam without any added water.
Low Sugar Rhubarb Jam (v. Standard Sugar Recipes)
I prefer a low-sugar rhubarb jam, with just enough sweetness to balance against the tart rhubarb. I only use around 1/2 cup of sugar to every pound of rhubarb (3 cups chopped), and my husband prefers even less (1/4 cup to a pound).
Many rhubarb jam recipes include a 1:1 sugar ratio by weight, which means one pound of sugar to one pound of rhubarb. In volume measurements that works out to 2 cups sugar to every 3 cups chopped rhubarb. If you prefer full sugar jams, you can use this higher sugar ratio with any of these recipes.
Full sugar recipes will yield considerably more jam than low sugar rhubarb jam recipes because the finished jam will cook down less.
Rhubarb Jam without Pectin
While rhubarb is a low pectin fruit (technically a vegetable really…) it’s possible to make a simple rhubarb jam without any added pectin. I make it by simply macerating the rhubarb in sugar overnight. This draws out the liquid from the sliced rhubarb, and the liquid can be cooked into a thick rhubarb syrup.
In the end, the rhubarb is added back into the jam pot and I find that it thickens nicely. I tend to like jams with a loser set, and this no pectin rhubarb jam recipe suits me nicely.
Even without pectin, it comes out thick enough to stay on the spoon, and won’t pour off easily…
This simple rhubarb jam has just two ingredients and no added pectin.
- 2 lbs Rhubarb, chopped into 1/4 inch pieces (about 6-7 cups)
- 1/2 to 2 cups sugar (see note)
- Mix the chopped rhubarb and sugar together. Allow the rhubarb pieces to macerate in the sugar overnight.
- Strain the juice from the rhubarb pieces and place the sugar/juice mixture into a jam pot.
- Bring the juice to a simmer over medium heat and cook for a few minutes until thickened.
- Add the rhubarb and cook for another 5 minutes until the rhubarb is cooked and the jam thickens to your preference. (You can test consistency on a small plate placed in the freezer.)
- Pour the jam into prepared canning jars with 1/4 inch headspace. Either store in the refrigerator/freezer for immediate use, or process in a water bath canner for 10 minutes for a shelf stable rhubarb jam.
This recipe yields roughly 3 half pint jars, and can be doubled if desired, but do not increase the recipe past double or the jam may not cook properly. A very low sugar jam uses about 1/2 cup sugar for 2 lbs rhubarb, but adjust the sugar level to your taste. Using 2 full cups of sugar will yield slightly more than 3 half pints.
Pounds of Rhubarb to a Cup: Generally, one pound of rhubarb equals about 3 cups of chopped rhubarb (or 2 cups cooked rhubarb). Stalk sizes can vary dramatically, but on average it takes 7-8 rhubarb stalks to make one pound of rhubarb.
Rhubarb Jam with Pectin
If you’re going to make rhubarb jam with pectin, the beginning of the process is the same. Start by macerating the rhubarb and almost all the sugar for about an hour (and up to 24 hours).
I always use Pomona’s Universal Pectin because it works regardless of the amount of sugar used. That makes it a much more versatile pectin, and it can be used in standard, low sugar, and no-sugar jam recipes.
Rhubarb Jam Recipe with Pomona’s Pectin
- 2 lbs Rhubarb (about 6 cups chopped)
- 1/2 to 2 cups sugar (divided)
- 1 tsp Pomona’s Pectin Powder
- 1 tsp Calcium Water (included with pectin, see note below)
Pomona’s pectin comes in two parts, a pectin powder that must be mixed in with a bit of sugar to prevent clumping and a packet of calcium that you dissolve in water to make “calcium water.” The calcium water is added to the fruit, and it works to activate the pectin.
Save roughly 1/4 to 1/2 cup of sugar to the side and don’t add it to the macerating fruit. Mix the pectin powder into the reserved sugar.
Add all the rhubarb and juice to a jam pot, along with the calcium water. Bring it to a boil and simmer for about 5 minutes. Add the reserved sugar/pectin mixture, bring the mixture back to a boil and simmer for 1-2 minutes before pouring the jam into prepared canning jars leaving 1/4 inch headspace.
Store the jam in the refrigerator or freezer, or process in a water bath canner for 10 minutes (adjusting for altitude).
The resulting jam sets much firmer and holds its shape well on a spoon.
Rhubarb Jam with Citrus Pectin
This variation is a bit of a compromise and allows you to make rhubarb jam with a good firm set without buying commercial pectin. Citrus fruits contain a lot of pectin, and some commercial pectin brands are actually citrus-based. Citrus juice contains a significant amount of natural pectin, as do citrus peels, but the best source is actually citrus seeds.
Old school jam makers would save up citrus seeds, either by drying them or later by saving them in the freezer. When it came time to make jam, a tiny sachet of citrus seeds was added into the fruit and allowed to macerate with either water or the fruit juice and sugar. This soaking process would extract pectin from citrus seeds, creating a naturally thick jam.
Rhubarb Jam Recipe with Natural Citrus Pectin
- 2 lbs Rhubarb (about 6 cups chopped)
- 1/2 to 2 cups sugar
- 1 Lemon (juice, seeds, and peel)
Start by juicing a lemon, saving the seeds and wrapping them into a tiny sachet using cheesecloth. Slice up the peel into smallish pieces, about 1” or so. Place all the citrus (peel, juice, and seeds) into a container with the chopped rhubarb and sugar. Make sure the seeds are at the bottom of the container so they’re soaking in the liquid to help extract more pectin.
Soak everything for 12-24 hours, and then take out the citrus peel. Leave in the sachet of citrus seeds, and place everything but the citrus peel into a jam pot. Simmer over low heat until the jam thickens, about 15 minutes for this rhubarb jam.
Pour the jam into prepared canning jars leaving 1/4 inch headspace. Store the jam in the refrigerator or freezer, or process in a water bath canner for 10 minutes (adjusting for altitude).
Rhubarb Jam Recipe Variations
Any of these rhubarb jam recipe variations can be flavored with other fruits for a completely different jam. Strawberry rhubarb jam is a great choice, as is a simple rhubarb jelly, but if you’re looking for more options, here’s a few ideas to try: