Strawberry freezer jam is a simple four-ingredient recipe (no pectin required) that's perfect for strawberry season. This small batch recipe makes a sweet jam that's filled with fresh strawberry flavor.
I love making freezer jam with fresh, seasonal fruits. Peach jam, pineapple jam, and raspberry jam are a few of my favorites. However, strawberry jam is the most popular, reader-favorite flavor!
Strawberry season is a great time to stock up on fresh, in-season strawberries. Making freezer jam is a great way to capture that fresh flavor to enjoy all year long.
You'll love this recipe because you only need four ingredients, most of which are probably in your kitchen already. We're using cornstarch to thicken our jam today instead of making a special trip to the store for pectin.
Strawberry freezer jam is perfect for spreading onto your morning toast. It can also be added to other recipes that call for strawberry jam, like no churn strawberry ice cream and strawberry jam popsicles.
Ingredients and substitutions
- Strawberries - Fresh, in-season strawberries are best. Grocery store strawberries, strawberries from your local farmer's market, or strawberries from your home garden all work great. You can also substitute with frozen strawberries that have been thawed.
- Granulated sugar - I have only made this recipe with granulated sugar. I have not made this recipe with sugar substitutes (if you do, please consult your sugar substitute packaging for correct quantities). Sugars acts as a preservative in this recipe, so if you do use a sugar substitute, keep in mind that your jam will not keep as long.
- Lemon juice - Helps cut the sweetness of your jam and adds a bright, fresh flavor. It also helps prevent the growth of bacteria. A small amount of lemon juice won't make your jam taste like lemon.
- Cornstarch - Thickens your jam. Omitting the cornstarch will result in a thin strawberry sauce (it will taste just as good, but will not thicken to a jam consistency). The amount of cornstarch needed depends entirely on the juiciness of your strawberries.
Tips and tricks
Stir until dissolved - Gently stir the ingredients until the sugar has dissolved and strawberries begin releasing their juices.
Jam look dry? - If your strawberries aren't in-season, you may want to add a splash of water and turn the heat down slightly.
Jam not thickening? - Very juicy, in-season strawberries may require extra cornstarch. Make a slurry of additional cornstarch with a bit of water and add slowly while stirring constantly until incorporated. Continue cooking until your jam has thickened slightly.
Cook until glossy - Your jam will look bubbly and frothy at the start, but eventually will look glossy and thick. This is one sign that your jam is done.
Do a spoon test - Does your jam also thickly coat the back of a spoon? It's done and can be removed from the heat.
Storage
Strawberry freezer jam will keep for 3-4 weeks in the refrigerator or about a year in the freezer. Keep your jar tightly sealed at all times to maximize freshness.
To thaw freezer jam, transfer the jar from the freezer to the refrigerator the night beforehand.
Frequently asked questions
One quart of strawberries makes two 8-ounce jars of jam. I like to use 8-ounce ball mason jars to store my jam. This recipe is very easy to double, triple, or more - so stock your freezer with as much jam as you'd like. Freezer jam will last about 3 weeks (or longer!) in the refrigerator, or about a year in the freezer.
No, there is no need to sterilize your jars for freezer jam. Sterilizing is done in canning to remove bacteria, yeast, or fungi before filling jars with cooked fruits or vegetables. Canned foods are meant to be stored at room temperature for long periods of time. Those jars need to be free of bacteria so that your food doesn't spoil. Since freezer jam is stored in the refrigerator or freezer at all times, there is no need to sterilize your jars beforehand. It's just like storing any other foods in your refrigerator or freezer. A regular, clean jar is sufficient.
No, freezer jam must be stored in the refrigerator or freezer at all times. This jam recipe is not shelf stable. This recipe is not a replacement for a traditional canning recipe for shelf stable jams.
If you'd like to make a lower sugar jam, add half the amount of sugar. Keep in mind the strawberry flavor will be more pronounced and tart. Do a taste test before transferring your jam into jars.
While I haven't tested it myself, readers have had success using alternative sweeteners with this recipe. If you'd like to make sugar-free jam, replace the sugar with your favorite sugar-free sweetener. Consult your sweetener's package directions, as some alternative sweeteners are more concentrated and should not be swapped at a 1:1 ratio. Sugar also acts as a preservative, so your low-sugar or no-sugar jam will not last quite as long when refrigerated.
Freezer jam is cooked quickly on the stovetop and stored in jars in the refrigerator or freezer. Regular jam is canned. Canning involves boiling the jars to preserve and seal them, making them shelf stable. Freezer jam takes less effort but requires refrigeration or freezing to preserve it.
Troubleshooting
The cornstarch listed in the recipe thickens the jam while it cooks. The amount of cornstarch needed depends entirely on the juiciness of your strawberries. Extra juicy, in-season strawberries can release a lot of juices as they cook, which requires more cornstarch to thicken. Out of season grocery store strawberries can be a bit on the dry side in comparison and may require less cornstarch. If your jam isn't thickening, add a slurry of cornstarch, 1 teaspoon at a time, and continue cooking.
If you're using out of season strawberries, maybe purchased at a local grocery store, they're likely to be less juicy than in-season strawberries from a local strawberry patch. If this is the case, you may not need any cornstarch at all. I recommend adding a splash of water in step 1 of the recipe if your strawberries aren't very juicy. I've made many batches of this freezer jam and the amount of cornstarch varies each time. Keep an eye on your jam. If it looks thick and dry, add a splash of water and remove it from the heat once your strawberries are softened.
Ingredients like fresh fruits can be inconsistent. Some strawberries can be very juicy and sweet, while others can be a little dry and tart. I've made batches of jam with store-bought berries as well as locally farmed in-season berries and the difference is vast. The key is to watch your jam as it cooks. If it looks dry, add a splash of water and turn the heat down. If it looks very wet and juicy, add more cornstarch.
I recommend cooking your jam on the stovetop until it thickly coats the back of a spoon. It will continue to thicken as it cools. If your finished jam is still thin, pour it back into a saucepan and warm over medium-low heat. Make a slurry of a teaspoon of cornstarch and a splash of water and mix into your jam. Cook until the jam thickens, adding more cornstarch as needed.
Larger quantities of jam can take longer to thicken and cook down on the stove top simply because you've got more ingredients in the pot. Give it more time and add more cornstarch as needed to help the jam thicken.
Recommended
📖 Recipe
Strawberry Freezer Jam
Ingredients
- 1 quart strawberries, chopped (about 4 cups)
- 1 cup granulated sugar
- 2 tablespoons lemon juice
- 2 teaspoons cornstarch, more as needed
Instructions
- In a saucepan over medium heat, add chopped strawberries, granulated sugar, lemon juice, and cornstarch. Stir occasionally until sugar has dissolved (add a splash of water if your strawberries are not very juicy). Bring to a simmer, then reduce heat to medium-low. Simmer for 10 minutes, stirring occasionally.
- Remove from heat and gently mash strawberries with a potato masher until desired consistency is reached. Return to heat and cook for another 5-7 minutes.
- Jam not thickening? If you're using very juicy, in-season strawberries, you may need additional cornstarch. Make a slurry of water and cornstarch (start with 1 teaspoon and add more if needed). Slowly pour slurry into jam mixture stir constantly until incorporated.
- Jam is ready when it thickly coats the back of a spoon and has a glossy appearance. Jam will also continue to thicken as it stands.
- Remove from heat and allow to cool before transferring to jars. When filling jars, leave about 1 inch of space at the top - your jam will expand slightly when frozen. Cool jam completely before adding lids.
- Store for up to 1 year in freezer, or up to 3 weeks in the refrigerator.
Equipment Recommendations
Notes
- If you're using very juicy, in-season strawberries, you may need to add extra cornstarch to achieve the proper texture. Add extra cornstarch, 1 teaspoon at a time, stirring until dissolved.
- Freezer jam is not shelf stable and needs to be stored in the refrigerator or freezer at all times. Jam will keep in the refrigerator for 3-4 weeks or in the freezer for up to a year.
- Sugar can be substituted with a sweetener alternative, but please consult your sweetener package for proper ratios (some are more concentrated than others).
- If using a sugar substitute, keep in mind that the sugar helps preserve the jam, so your sugar-free jam will not keep as long in the refrigerator.
- When doubling or tripling this recipe, your jam will take longer to cook and thicken.
This was fantastic! Every other jam/freezer jam recipe I've tried has tons of sugar and is just sickly sweet. This has a nice level of sweetness but still tastes fresh. I ended up needing to use closer to 2 tablespoons of cornstarch because my berries were freshly picked. Will be making this again and again!
I followed the directions but it did not set well. It is too runny to use on toast and biscuits. The strawberries were large and juicy. I will add more cornstarch next time.
Hi Ida, I agree. If you'd using in-season, juicy strawberries, you may need to add a bit of extra cornstarch. The jam you have on hand can always be warmed up again on the stovetop with more cornstarch to help thicken it.
Hi Heather I love this recipe. The best part was only 1 cup of sugar with 5 cups of strawberries. I froze 25 1/2 cups of the jam, the thing is I bought way to many. I have about 8 quarts left so I baggied them up and froze them. They aren't to tasty when you pull them out - do you have a low sugar recipe for water bath? ty
Hi Charleen, I do not have any canning recipes, only freezer jam recipes like this one. However, I did find a promising looking low sugar strawberry jam recipe here: https://www.sustainablecooks.com/easy-strawberry-jam/
Hope this helps!
I made the jam like the recipe , it is not thickening, any idea what I should do
Right now I am letting it cool.
Hi Mary Ann, the cornstarch is the thickening agent in this recipe. I find that if I have very juicy, in-season strawberries, sometimes they need a little extra cornstarch. You could try making a slurry of a few teaspoons of cornstarch with a few teaspoons of water. Stir this into your jam over medium-low heat, then allow it to cool completely (it will also continue to thicken as it cools).
I had the same problem. I tried the slurry and that didn’t help. Its tasty. But more like strawberry soup.
Hi Becky, were you using very juicy, in season strawberries? This recipe doesn't add liquid other than the 2 tablespoons of lemon juice, so it sounds like your strawberries were very juicy! I'd recommend simmering for longer, until the jam appears to thicken in the pan.
I'm just curious, is the cornstarch really necessary? I seem to remember when I was young my grandmother taught me how to make strawberry jam with just strawberries and sugar. She said the strawberries contain enough pectin naturally to thicken the batch. I may have remembered it wrong though. Also we would have use wild strawberries so maybe there is a difference.
Hi Timothy, I've made this recipe dozens of times and find that the cornstarch is necessary, which is why I include it in the recipe. I've used both store bought and garden strawberries (I have not tried wild strawberries) and I found that garden strawberries are usually much juicier. You might be able to get away with using only sugar with store bought strawberries and not adding any additional liquid. If you give it a try without cornstarch, let us know how it goes!
this is amazing! Just made it this afternoon -- will definitely be making again! Thank you for posting!
I found some frozen strawberries, can I use those in place of fresh?
Yes, frozen strawberries that have been thawed will work just as well as fresh!
I made this recipe with my 8 year old grandson who with adult supervision did most of it himself. It turned out wonderful and we liked the fact that it wasn't super sweet and the berry flavor really was the "star" . Thanks so much for the recipe and I will be making it again.
Thank you for the great review, I'm so glad you both enjoyed making jam today!
This is such a yummy recipe - I made one batch Saturday, and am making two more batches today, Monday. (1/2 of the first batch is already eaten !)
I had some strawberries that where about to over ripen. I came to your site and found this fruit spread recipe. I made 3 small jars for my fiancé who loves fruit spreads on his toast and had just used up the last we had in the house this very morning. Thank you so much. You have helped me not to waste foods during a safer at home period😊
I love love love this recipe. I use it often. Could I substitute peach and keep the same ingredients? Thank you for sharing once again.
Hi Lisa, I'm so glad to hear you enjoy the recipe! Yes, you can replace the strawberries with peaches. Here's my recipe for peach freezer jam: https://thetoastykitchen.com/peach-freezer-jam/
Could I substitute Splenda for the sugar?
Hi Marisa, yes, you can use splenda instead of sugar, using the same measurements.
Your jam may not last as long in the refrigerator, because sugar does help to preserve the jam and give it a longer shelf life when refrigerated. I haven't tried it myself, but if you do, please let us know how it goes!