Rhubarb Strawberry Jam

When rhubarb season rolls around, I just can't resist.
At the very least I have to make ONE batch of jam to put away (for at least a little while). This way rhubarb can be savored much later in the year (or early the next). One nice thing about jam is that you can get a bit of that great flavor, and it doesn't disappear all at once. A jar of jam theoretically lasts longer than, say, a pie or tart might.
(And yes, I like to reuse certain jam jars for their shape and style.)

I think it's my all-time favorite confiture.
There are just a few ingredients, simple and perfect.
When I make a batch I don't really want to share, but I know its better for several reasons that I do so.

This is an updated version of a rhubarb berry jam I posted years ago.
I have this habit of making lists and notes on Post-its and misplacing them, so it behooves me to write recipes elsewhere ASAP so I don't have to do a frantic search or take the time to figure something out all over again.
Some concepts here are based on The Blue Chair Jam Cookbook by Rachel Saunders- but there is no actual rhubarb strawberry jam listed in the book.

It's a two-day project (or maybe some prep the afternoon or night before, not too much work on Day 1), and I would totally recommend the use of a kitchen scale for a recipe like this that utilizes larger amounts.

I agree that you need to let the rhubarb shine, making it the greater portion of the fruit in the recipe. Rhubarb certainly has it's own flavor, tart and distinctive. As I write, I'm trying to think of ways to describe the flavor, but am having a hard time coming up with anything...
I don't know. To me, there's something amazing about that flavor.

 

Obviously, as the jam cooks the fruit will break down, so it's a personal preference to have larger pieces of fruit to retain texture and so you really see and taste what's in the finished jam.

But, the jam is nice on plain yogurt, with pound cake, on good vanilla ice cream, as a filling for a tart, crostata, or cookies, and of course toast.

Rhubarb Strawberry Jam
makes about 8, 12 oz jars

Day 1
2 3/4 lbs. (about 1 kg and 247 g) rhubarb (*after being trimmed and sliced)
1 3/4 lbs. (about 794 g) cane sugar
2 oz (1/4 c or 60 ml) lemon juice

To add on Day 2
1 1/2 lbs. (about 680 g) strawberries, sliced if large
1 3/4 lbs. (about 794 g) cane sugar
3 oz (1/4 c plus 2 T or 90 ml) lemon juice, separated


Clean the pieces of rhubarb, cut off the top and bottom ends, and slice into 1-2 inch pieces. Weigh out 2 3/4 lbs. of the rhubarb, place in a glass container, add the sugar and lemon juice and stir to combine.
Cover tightly with plastic wrap and leave in a relatively warm place to macerate for at least 12 hours and up to 24.

When ready to make the jam, place a small plate with several spoons in the freezer (for later, to check the consistency of the jam).

Place the rhubarb along with any juices in an 11-12 qt. copper preserving pan or a nonreactive kettle. Add the strawberries, sugar, and 2 oz of the lemon juice and stir until the sugar is thoroughly combined.

Bring the mixture to a boil over medium-low heat, stirring occasionally with a heatproof rubber spatula about 10 minutes. Raise the heat to medium-high and continue to stir occasionally.  As the jam thickens, stir more frequently, relatively constantly near the end, making sure to scrape the sides and bottom of the pan so it does not scorch. If the jam seems to get too sticky on the sides of the pan, perhaps reduce the heat a bit. Cooking time at the higher heat will take about 20 minutes depending on juiciness of the fruit and evaporation. Add the rest of the lemon juice, stir through, and continue to cook the jam for 2-3 minutes.

Remove the pan from the heat (if it seems a little thin remember that it will continue to thicken as it cools), and place a spoonful of the jam on the frozen plate. Put the plate with the spoon back in the freezer for a few minutes. When the time is up, take the plate and spoon back out of the freezer and lift the spoon to see if the jam is runny. If it's watery and easily falls off the spoon, you'll need to cook it a few minutes longer and re-test the consistency. If the jam is instead thick and wrinkles a bit when you nudge it with your finger, it's finished and ready to place in glass jars.

NOTE ON JARS:
Lids should be clean and jars should be HOT and sterilized. You can use an empty dishwasher on a hot cycle, but you can boil the jars or use your oven.  If using your oven, place clean jars on a pan in a 250 F (120 C) oven for 30 minutes. Place a little jam in one of these jars and see if it bubbles or boils. If so, the jar is a little too hot and should cool off a bit before continuing.

Fill the hot jars with the finished jam, leaving about 1/4 inch space. Wipe the rims with a clean damp cloth, and screw lids on the jars. 

Jam can be left as is, to cool, or placed in that 250 F (120 C) oven for 15 minutes. 
If the oven method is used, the filled jars should be left to cool on a wire rack overnight before storing them.

Jars that have NOT been finished in the oven should be refrigerated.
Any jars that have been finished in the oven which are not completely sealed and whose centers are not convex should also be placed in the refrigerator.

Properly canned jars can last a year or two in a pantry.
Mine don't last that long (I give some away and those I keep, I usually just leave in the fridge).