Regardless of whether or not you are going to can this jam to make it shelf stable, it’s a good idea to properly wash and sterilize the jars you will be using. This recipe will make 6 (8-ounce) jars or 3 pint jars, so gather whatever collection of jars you’d like to use and either sterilize them in the dishwasher with the sterilize cycle, or boil them in a pot of boiling water for 10 minutes – this includes the lids and rings too. Let everything air dry.
The next step is to put a small plate or two in the freezer. This is so that you can test the jam when the time comes to know if it has cooked for long enough and will set up in your jars.
While you’re doing all this prep, chop up the rhubarb and strawberries and mix them with all the other ingredients – water, sugar, lemon juice, lemon halves, seeds and all. Letting all the ingredients sit together for a little while before you boil it into jam allows for all the intense sugars in the fruit to come out and you’ll end up with a more vibrant jam. After an hour or so, bring everything to a boil and let it simmer strongly, skimming off any of the impurities that rise to the surface as foam. Removing as much of the foam as possible will leave you with a more translucent jam.
Once your jam has simmered for about 30 minutes, it should be ready to test. You’re testing to see if the jam has reached its gel or set point and this is where those plates in the freezer come in. Dropping some of the jam onto a frozen plate chills it quickly so that you can see what the consistency will be like when the jam cools. If it runs on the plate, it needs a little more time in the pot. If it sits on the plate, it’s time to take the pot off the heat.
Transfer the jam into the sterilized jars very carefully – hot jam makes a nasty burn. Then, you can decide whether or not you want to process the jars in a water bath to seal them and make them shelf stable, or if you know yourself better and realize that these delicious jars of jam will be gone in two weeks time just refrigerate them once they have cooled. 😉
I haven’t tried this yet because I don’t have Rhubarb…but I do have strawberries. Could you just use strawberries for the recipe? How does this jell without pectin?
I have heard of putting apples in the recipe with strawberries for the pectin but never
lemon. Have you ever made strawberry freezer jam?
Hi Jean. This jam is not super thick, but it gels enough to be spreadable. If you’re interested in making plain strawberry jam, I have another recipe for that here (along with a video): https://bluejeanchef.com/recipes/strawberry-jam/
Can you use a sugar subistite
Using sugar substitutes is a little tricky because you’re trying to replace an ingredient (sugar) that does more than just sweeten. Sugar also helps the jam gel AND is the main preservative in the jam. There are also many different varieties of sugar substitutes available these days which all have their own properties. If you did want to try making it without sugar, you might want to add a no-sugar pectin to help it gel and read the instructions on your sugar substitute package for guidance.
I just wanted to know if I could substitute a sweetener substitute like Splenda for the sugar and if it would gel?
Hi Julie. Substituting the sugar is a little tricky. Sugar not only sweetens the jam, but reacts with the pectin to form a web that helps the jam gel and thicken. Sugar also is the main preservative in the jam – sugar allows the jam to boil at a higher level (more like 220ºF instead of 212ºF) and kills bacteria. So, if you want to substitute Splenda, you would need to add some no-sugar pectin OR simply cook the fruit down a lot more until it starts to thicken on its own due to evaporation. Then, stir in your Splenda to sweeten it and jar it right away. It won’t keep as long as sugar jam, so only make as much as you need.
Can you also make freezer jam from this recipe?
You could try to make freezer jam from this recipe, but it might not be as sweet as you would like it to be. Freezer jams don’t cook the fruit and sugar for very long and as a result there is very little evaporation and hence less concentration of flavor. So, if you want to try to make freezer jam, add more sugar to the recipe. You could also just make this jam and if you don’t want to can it, store it in the freezer for up to a year.
Looks VERY yummy, as I love rhubarb. Can this be made with rhubarb only? Have not made it yet!
Hi Kathleen. Yes – you can absolutely make this with just rhubarb. Just replace the strawberry quantity with the same quantity of rhubarb and off you go!
Hi Meredith,
I just made this last night! Delicious!! We have a beautiful crop of both red and green rhubarb ready to be picked. I bought some strawberries and spent quality time with myself in my kitchen making a batch of this jam. My family will really enjoy this treat when they return from fishing up north. This is my first time making rhubarb jam, and this recipe is a keeper/winner!! 🙂
Thank you for sharing this.
Karen
Albany, WI
Can this be made with frozen rhubarb and frozen strawberries?
Yes, but you might need to let it reduce a little longer so that some of that extra liquid evaporates.
I have made this a couple times. The first attempt was more of a strawberry-rhubarb sauce, though I think using frozen strawberries was the problem there. Second time, fresh strawberries, but it was still runnier than I’d like after cooking much longer than the recipe calls for. I added cornstarch and that did the trick. Perfect jam in the end.
I’ve made this recipe two years in a row. This year I added almost 15 more minutes to the cooking time. It was a lot more thicker. This is really a delicious jam and no problem to make. Thank you for such a nummy jam recipe.
I made this before but didn’t use lemon… Now I am trying it with the lemon and so far it works great. So glad you sent this recipe. Well I am back and that jam is awesome. Now I will use Lemons all the time.
Tried this recipie today and it is awesome! I was able to fill 7 jam jars which I canned using a water bath. It does appear to be a softer set jam but definitely spreadable. Hubby will probably use it as a topping for ice cream! It’s yummy!
Simple, fun made great tasting jam.
Why the lemon seeds?
Lemon seeds contain a lot of pectin which help to thicken the jam.
ML
Hi! Could you substitute the lemons for pectin ?
Hi Danielle. Yes, you could use pectin instead of the lemons if you like. How much you need to use depends on how thick you want the jam to be. For 10 cups of fruit, I would suggest 10 to 14 Tablespoons.