Making Jam from Frozen Fruit

May 22, 2020(updated on September 20, 2021)

My friend Shae has shut down her blog, Hitchhiking to Heaven. Before she took it offline, she offered up some of her old posts so that they can continue to live and be useful.

Last year, two things came into my life that changed the way I preserve fruit. One was an upright storage freezer, which now lives in the basement. The other was a Food Saver, which allows me to freeze fruit in vacuum sealed packages at the height of just-picked excellence, without the danger of ruin from stale air and freezer burn. (Even before the Food Saver, I’d started freezing summer fruit in this way, using heavy-duty freezer bags and sucking out the excess air through a straw or with my mouth — all of which is easier than it might sound.)

The ability to freeze good fruit is important to me, in part, because we spend the peak preserving month of August far away from home, at our cabin in Alaska. Just before we leave, I am slammed with pounds and pounds of berries and plums — more than I could sanely process, given everything else that’s going on. It’s a huge relief to be able to flash freeze, package, and tuck away the harvest to make jam later.

When I started to create jams with my frozen summer’s haul, I was of two minds: Mostly, I loved having the luxury of combining so many fruits. Opening the freezer to securely preserved strawberries, blackberries, raspberries, plums, and figs was like diving into a chest of colorful, edible art supplies. I had strawberries to blend with feijoas when the latter showed up in November. (I’ll be sure to post that recipe next fall when feijoas come in again. It was one of my favorite jams of the year.)

I made a luscious plum, strawberry, and ground cherry jam that I never would have thought of if I’d used up all those strawberries in June. The frozen plums — at least three different varieties – found their way into almost everything, lending a tart complexity and pectin boost to jams from October until just last week, when they finally ran out.

But I also felt guilty. Isn’t it cheating to make jam from frozen fruit? I let flavor decide that question. It’s all good jam. Because the fruit was frozen with care, at the very point where I would want it for jam making — some of it perfectly ripe and some of it just under — the difference in flavor was negligible to nonexistent. As Darina Allen says in her gorgeous book, Forgotten Skills of Cooking:

If you don’t want to spend your whole summer in the kitchen, the most practical approach is to freeze fruit in perfect condition in small, measured quantities, so that you can make jam as you need it throughout the year. Jam made from frozen fruit will taste infinitely fresher and more delicious than a six- or seven-month-old jam even if it is made in peak season.

So. Yes. You can make some damned fine jam from frozen fruit. Here, I thought I’d share a few tips and the method I like to use for jamming frozen fruit.

How to Make Jam From Frozen Fruit: Tips and Tricks

Start with the best. What goes into your jars is what you get out of them, so use the best fruit you can find. Depending on the type of fruit, you’ll want to freeze it at the peak of flavor or when it’s just a tad underripe. Hitting that peak of ripeness is critical for fruits like strawberries or figs, where a little bit to one side or the other makes all the difference between the jam you want and the one you don’t. With fruits like plums, blackberries, or raspberries, however, I like a mix of perfectly ripe and just under, for both the extra pectin and the extra pucker that the less ripe fruits provide.

Don’t get it wet. I pick over berries. I gently spot clean plums. I remove any bad bits from strawberries. But I don’t wash fruit before I freeze it. It’s all organic or foraged from unsprayed places. I pick it myself, or I know the people who do. I’m also going to boil the bejeezus out of it, so I don’t worry about skipping the wash. (As an aside, some professional jam makers I know and respect don’t wash their organic fruit before jamming it. That’s how I learned to stop doing it, myself. So if a professional jam maker jumped off a bridge, would I jump off a bridge, too? I suppose I might.)

Slice, dice, and weigh. Before you freeze the fruit, cut it to the size you think you’ll want it to be when you use it later, because you probably don’t want to mess around with trying to chop up plum halves or whole, huge strawberries after they’ve been frozen. If you want different textures for different jams, freeze multiple bags, each containing the size you’ll want. You may want to plan for bags of various weights, too. I prepped a lot of two- and three-pound bags, but found that I also loved having single-pound bags to play with.

Flash freeze first. You already know about this, right? It’s where you put the individual pieces of fruit on trays and freeze them until they’re just solid. Then you put the flash frozen fruit into freezer bags. This is how you avoid things like whole bricks made of blackberries. Do note that some fruits have special needs when it comes to freezing.

For example, I freeze figs in sugar syrup to retain color and texture. You can learn about that here. And you can find detailed information about freezing other types of fruit here. I have never, for example, frozen peaches, nectarines, or apricots because I haven’t had enough to warrant it. I’d want to check up on the particulars of freezing those or other fruits before attempting it for the first time.

Get the air out. Suck it out with a straw, give your freezer bags mouth to mouth, or get a Food Saver — just extract as much air as you can before you seal the bags. Then double check the seals.

Label it now or regret it later. On the outside of the freezer bag, jot down not just the fruit it contains, but the weight and the date you froze it, along with anything else you might want to remember, like where you picked it or who gave it to you. You’ll be glad you did. (For those of you who are ahead of me in the labeling game, would you please tell me your favorite way to label freezer bags? I write on them with a sharpie, but that makes reuse challenging. I travel with my toiletries in a bag labeled “Blackberries 2010.”)

Plan before you jam. Before you start pulling summer out of the freezer, think about what you want to make. It’s not a big deal — just some recipe notes so you can get in and out of the freezer quickly and not grab or thaw a lot more than you need.

Mmm . . . macerate. This is the best part. I start almost all my frozen fruit jams by macerating the fruit in sugar while it thaws. Doing it this way means you won’t end up with sad, pulpy bits of skin floating in a mess of juice. As the fruit thaws, the sugar nestles it and absorbs the liquid, so you end up with a mixture that is thick, bright, pectin rich (provided you’ve chosen a blend of fruits that provides enough pectin to make a successful jam, which is actually kind of hard not to do) and ready to cook.

I don’t add powdered or liquid pectin to my frozen fruit jams and I’ve not yet had a bad experience with one. In terms of how much sugar to use, that’s up to you and your fruit. I usually use 60%-75% of the weight of the fruit, depending on how much pectin it has (less pectin = more sugar) and how sweet it is to start.

Anyway, go clean out your freezer and make some jam. Because it’s spring and rhubarb is already upon us!

This piece was originally published on Hitchhiking to Heaven on March 25, 2012 and was written by Shae Irving.

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46 thoughts on "Making Jam from Frozen Fruit"

  • Similarly, I made crockpot blueberry butter (from my much-used copy of Marisa’s brilliant first cookbook) with a couple bags of frozen blueberries shortly after the the stay-at-home order went into effect, to free up some much-needed freezer space. Worked brilliantly; it’s good to know that frozen fruit can be used to make butters as well as jams.

  • Just so we’re clear: Organic farming DOES use pesticides, they’re pesticides that are labeled acceptable for use on crops that get the “organic” label, but they’re still bug and weed killers, and you don’t want to consume them. So if you’re concerned about pesticide residue you will need to wash your fruit, even the organic stuff.

  • I have found that labeling my freezer bags with a strip of tape on which to write works well- as long as the bag is clean and dry. The tape will stick in the freezer and can be removed when washing the bag. I use this method for all my “preserved -repackaged foods”

  • Marisa, thanks so much for posting this blog entry from Hitchhiking to Heaven.! That was such a good resource. I will look forward reading more. Take care.

  • Wonderful instructions! I just wanted to mention that if you use glass canning jars, please think about putting them on a shelf with a bar across the front of the shelf so that in case of an earthquake or tornado or such, all your food in glass doesn’t end up on the floor. A piece of scrap wooden molding works great or even a cord. Think of those videos you see of the grocery stores after an earthquake with all that food ruined! I’m from California. I also take the rubber shelf liner that you can often get at a dollar store and cut it and wrap my glass jars with a rubber band around them, so they don’t hit each other and break. Maybe it’s being overcautious, but why not?

  • If I am following a jam recipe that calls for 5 cups of fresh sour cherries, and I am using frozen, do I need to measure out more since they will become smaller as they thaw? Is there a good ratio for this to ensure I am using the correct amount of fruit? Thanks so much for your help!

  • i am doing frozen rhubarb and frozen apple,I just threw it all in a hugee pot and let it simmer,do i need to drain it?

  • Is the ratio of fruit to sugar described in the article safe for water bath canning or would this be considered freezer jam?

    1. Sugar doesn’t make something safe or unsafe for the water bath. Only acid content can do that. So the ratio described in this post is perfectly safe.

  • Marisa, I hope you can answer this question for me – I have searched but not come up with an answer, and even emailed OSU, but haven’t heard back –

    In cleaning out a chest freezer (Yay to getting an upright freezer!), I discovered some fruit I had frozen (figs, Italian plums, persimmon pulp), that had gotten buried in the chest freezer for two years! 🙁

    I am trying to determine whether or not I can still make decent preserves with them. I don’t want to waste time and energy and supplies to make preserves that won’t taste good, but I certainly don’t want to compost all that fruit unnecessarily.

    Thanks for your help!

    1. You should defrost and taste the fruit. If it tastes okay, it’s fine. If it tastes freezer burnt, you should throw it away.

  • I recently made strawberry jam using frozen berries.Seems to me it is a little bit thick,can I add something to it like berry juice and add it when hot or from cold? thankyou B Whitehead

    1. You can certainly thin it down with a little water or juice when you open the jar to use it. You’ll need to heat it with the liquid.

  • If I want to use pectin then I cannot macerate the fruit with sugar, right? I’m using pectin because I don’t want all that sugar. Or do I just thaw like normal and add pectin and later add sugar?

    1. You can still macerate, even if you’re using pectin. And are you using a low sugar pectin? If not, the amount of sugar in the recipe will be the same whether it’s made with pectin or not.

  • I want to make strawberry rhubarb jam, Is it ok to use frozen strawberries. Would sliced be ok or whole berries.

    1. Strawberries are very low in pectin and freezing them further breaks down the available pectin. So when you work with frozen strawberries, you typically need additional pectin. But using them is just fine.

  • I made a batch of mixed frozen berry…. I think the culinary term is “road tar”. My solution is to warm a jar (thankfully, I put it up in the tiny jam jars) in the microwave, 30 seconds or a little less, and stir in some creme de cassis. It is delicious as a jam or a dessert topping. Even with added liquid it needs to be rewarmed every time it comes out of the fridge.

    1. I’m so sorry to hear that it was overset! I’m glad you’ve figured out a way to use it despite the intensity of the set.

  • Hi Marisa,
    You are just so absolutely correct with your measures!
    Every recipe states 1 cup fruit and 1 cup sugar. For sliced strawberries, if using volume, you would use 20% more sugar. That’s a lot.
    I always use weight, then decimate that sugar content to about 60-70% of fruit. The jam doesn’t set perfectly (I call it ‘spoon jam’) but it’s not runny and doesn’t matter to anybody. You can actually taste the fruit rather than the sweetness.
    Thank you!

    1. I often use pectin. It just depends on the variety of fruit, the size of the batch, and the amount of sugar I’m using.

  • I have some black raspberries that I grew last Summer 2021 and they have been in the deep freeze. They look good and don’t have much ice in them at all. I was actually surprised. THis may be because as I remember they were not overly ripe or “wet” when I stored them. Do you think they are ok to make jam. I pulled out a few and tasted them and I didn’t notice any off flavors. Still not sure however. What do you think?

  • Good day, thank you for the recipes and advice. I have one question. I was making haskap jam and the recipe called for equal amounts of berries to sugar by volume? What does it mean by volume< Did did equal cups of sugar and berries and it came out more of a syrup.

    Thanks, Norma

    1. By volume simply means by cup measurement, which is sounds like what you did. If the jam came out more like a syrup, you probably needed to cook the jam longer. With jams that don’t have additional pectin, you typically need to cook until the temperature reaches 220F.

  • I have not been able to get this in my brain, freezing strawberries. I washed mine before reading that I shouldn’t have. I individually froze them on a sheet pan. Now, how should I use my frozen strawberries? How to I measure them for my recipe? I am sure when they thaw there will be much water. Suggestions?

    1. You could defrost and then drain. Or just be prepared to cook the jam a little longer in order to work out the extra water.