Last Updated on September 17, 2021
Can you freeze rhubarb while it’s coming in by the truckload? Thank goodness, yes! While rhubarb season is short, the uses for rhubarb are so numerous that freezing rhubarb helps extend the time you can enjoy rhubarb crisp, pie, soda, and so much more. Here’s what you need to know about how to freeze rhubarb.
If you’re like many rhubarb fans, you find yourself multiplying the rhubarb plants in your garden and inundated with more delicious rhubarb in late spring than you (and all your neighbors) can possibly keep up with. I now have eight rhubarb plants growing in our tenth-acre lot, and that means a LOT of rhubarb, waaaaaaaay more than we can use at once.
But you can’t leave those precious rhubarb stalks on the plant, or they’ll soon become tough and unusable. The answer: freezing rhubarb for later use.
Freezing is one of the easiest food preservation methods around, one any total novice can dive into without having to invest in any special equipment. You’ll love having loads of local produce at the ready for all sorts of delicious dishes.
CAN YOU FREEZE RHUBARB?
Yes, you can absolutely freeze rhubarb! Best of all, freezing rhubarb is as easy as chopping your fresh rhubarb stalks and putting it in the freezer. Once cooked, frozen rhubarb tastes really similar to fresh and works well in sauces, soups, crisps, and so many other recipes.
You can freeze raw rhubarb, or you can cook your rhubarb first and then freeze it. I prefer to freeze the raw rhubarb and then cook it once I know what I want to make. Freezing rhubarb stalks raw is easy and quick, and then I have the chopped raw rhubarb ready for whichever dish I’m making.
Freezing rhubarb and other in-season produce is one way to eat seasonally and locally all year round.
Rhubarb freezes well, and thawed rhubarb is pretty indistinguishable from fresh when baked into a delicious rhubarb crisp or turned into rhubarb sauce. And if you’ve never tried rhubarb leather, you need to make sure to use some of your rhubarb abundance for that as well. Seriously, rhubarb leather is A-MA-ZING.
DOES FREEZING RHUBARB MAKE IT POISONOUS?
Contrary to internet rumors, freezing rhubarb will not render it poisonous. Some people confused what happens when a rhubarb plant outside freezes with preserving rhubarb in your freezer. If your rhubarb plant suffers a hard frost, the oxalates concentrated in the leaves (which we avoid because they are in fact toxic if consumed in large quantities) move to the stalks, making the stalks much higher in oxalic acid than they usually are.
Experts recommend discarding stalks that have been exposed to hard frost to avoid excess oxalic acid. According to garden experts at several university extensions, you’ll be able to see damage to the leaves, and the stalks will become mushy. Don’t use those when you’re harvesting and freezing rhubarb.
We had a bunch of nights below freezing late this spring, so I made sure to cover my plants to protect our precious rhubarb harvest from freezing.
Freezing rhubarb stalks from a plant that hasn’t gotten frostbitten does nothing to change their normal oxalic acid content and can be safely put in your freezer.
DO YOU NEED TO PEEL RHUBARB BEFORE FREEZING?
No, rhubarb stalks do not need to be peeled before freezing. If you’re a bit late in the season or if your plants haven’t been watered consistently, your rhubarb stalks may have toughened, and peeling might help to make them a bit more tender. But there’s no need to peel most stalks before freezing rhubarb. A good thing, too, as peeling rhubarb is a lot of extra work!
You can check if the stalk is tough by cutting yourself a little taste before going to all the trouble of chopping and freezing pounds of rhubarb. It should be juicy and easy to chew, a little like celery in texture, but less stringy. If it’s past its prime, stalks will be difficult to chew, and you’ll be left with a fibrous ball in your mouth. Be forewarned if you’re sampling while you’re preparing your rhubarb for the freezer: raw, unsweetened rhubarb is very sour.
Typically rhubarb is harvested in late spring as soon as the stalks have sized up. Once temperatures rise in summer, rhubarb stalks toughen, though some growers tell me if you keeping a plant picked, you can harvest rhubarb throughout the season.
We’re too busy preserving all the other yummy summer produce to try, so we just freeze our excess rhubarb — that is, if we have any after making as much fruit leather as possible.
DO YOU NEED TO BLANCH RHUBARB BEFORE FREEZING?
If you’re going to use your frozen rhubarb within a few months, then, no you don’t have to blanch it first. But remember those months are also the ones when your garden is producing like crazy and it’s all you can do to keep up with the juneberries, zucchini, tomatoes, peaches, elderberries, and apples. So realistically, you likely won’t get to your frozen rhubarb again till the garden’s put to bed for the winter. And it’s such a treat to have its bright, tangy flavor in the colder months.
Rhubarb does go beautifully with raspberry, elderberry, and peach, though, so you can do a mixed-fruit crisp or baked oatmeal with unblanched frozen rhubarb as these summer crops come in. Or use your frozen rhubarb to replace your stock of rhubarb leather when you run out and have fun combining it with other in-season fruits. Raspberry rhubarb leather is delicious also, and you can find a recipe for elderberry-rhubarb leather in my book, Everything Elderberry.
But if you want to enjoy all that yummy rhubarb in January, blanching it before freezing will help stop the enzymes that can degrade frozen raw foods and leave you with higher-quality rhubarb than if you just popped it in the freezer without blanching first.
On the flip side, blanching involves not only extra time, but extra energy to heat water and make ice. Skipping the blanching step means less energy used in your food preservation project, as well as time savings. As someone always strapped for time and looking for ways to trim energy use, I tend to skip the blanching step and use my rhubarb months later anyway.
The frozen rhubarb might be of slightly lesser quality, but it may not be enough to go to the extra trouble of blanching. If you don’t have time or energy, go ahead and freeze your rhubarb without blanching, and just try to use it sooner rather than later.
The choice is up to you. I’ve included instructions for blanching if you choose to go that route.
WHAT SHOULD YOU USE FOR STORAGE WHEN FREEZING RHUBARB?
You can use bags, jars, or plastic containers for freezing rhubarb. If you have a vacuum-sealer, vacuum-sealed bags will do the best job at preserving freshness, but if not, you pack a normal freezer bag tightly and squeeze out all the air, you’ll likely evade freezer burn for many months.
HOW LONG DOES FROZEN RHUBARB LAST?
Blanched rhubarb packed tight with the air removed (or vacuum sealed) may last in the freezer for up to a year. Rhubarb that hasn’t been blanched or is packed more loosely will start to degrade after a few months, but depending on the recipe, you might not notice much. Once blended into rhubarb sauce or baked in a crisp, frozen rhubarb is pretty darn similar to fresh, even if it wasn’t stored in optimal conditions.
FREEZING RHUBARB STEP BY STEP
FREEZING RHUBARB WITHOUT BLANCHING FOR SHORT-TERM STORAGE
- Make sure all the leaf is removed from your rhubarb stalk, and trim away the ends where the stalk joined the plant.
- Rinse well to remove dirt or stuck-on plant matter, then pat stalks dry.
- Chop into pieces about 1/2 inch to an inch wide and arrange on a baking sheet. (These half sheets work well for the freezer.)
- Allow to freeze 4-6 hours, till frozen through.
- Transfer frozen rhubarb to a bag or storage container, packing tightly. Remove as much air as possible by folding the bag and squeezing out the air. You can use a straw to remove additional air after you’ve zipped the bag most of the way closed.
- Seal tightly and freeze for up to 3 months.
BLANCHING RHUBARB BEFORE FREEZING FOR LONG-TERM STORAGE
- After you’ve cleaned your rhubarb stalks as described above, chop into 1/2-inch to 1-inch pieces.
- Submerge chopped rhubarb in boiling water or steam for 1 minute. The easiest way to blanch vegetables in boiling water is with a built-in colander or basket like this one so you can easily lift them in and back out all at once.
- Remove your rhubarb from the boiling water and immediately submerge in a prepared ice-water bath to stop the cooking process. Leave in the ice water about 2 minutes.
- Drain cooled rhubarb and allow to dry.
- Arrange on a baking sheet and pat with a towel to remove excess water.
- Put in the freezer for 4-6 hours, till frozen through.
- Transfer to a bag or storage container, packing tightly. Fold the bag and squeeze out excess air. For best results, use a straw to remove additional air after you’ve zipped the bag most of the way closed.
- Seal and freeze for up to a year.
WHAT TO DO WITH YOUR FROZEN RHUBARB
How to use your piles of frozen rhubarb?
- Whir up some luscious rhubarb sauce
- Turn some into rhubarb leather
- Bake this easy rhubarb crisp
- Enjoy a spritzer made with this 2-ingredient rhubarb juice
- Or give one of these creative rhubarb recipes a whirl!
Now that you know how to freeze rhubarb, how are you planning to use it?
Pin to save this info on freezing rhubarb for later!
Susannah is a proud garden geek and energy nerd who loves healthy food and natural remedies. Her work has appeared in Mother Earth Living, Ensia, Northern Gardener, Sierra, and on numerous websites. Her first book, Everything Elderberry, released in September 2020 and has been a #1 new release in holistic medicine, naturopathy, herb gardening, and other categories. Find out more and grab your copy here.