I don’t want to sound too dramatic when I say this, but Strawberry Sun Jam is life-changing jam! Once you try this, you will never want to have any other jam again. Strawberry Sun Jam is going to ruin all other jams for you!
If you’re okay with that, than feel free to read on…
And not only is it the best jam ever, Strawberry Sun Jam is also one of the EASIEST jams I’ve ever made! Mother Nature does most of the work for you. Plus it uses NO PECTIN or odd ingredients, doesn’t require canning, and has a reasonable amount of sugar. Real jam-making does require some sugar if you want to have good jam, but the amount in this recipe is much lower than *most* real strawberry jam recipes.
What is “SUN” Jam?
It’s called “sun” jam because the sun turns it into jam- literally.
Here’s the short version:
Mash strawberries together with sugar and honey.
Cook for a just a few minutes to dissolve the sugars.
Spread the strawberry mixture onto large pans.
Put the pans out into the sunshine.
Because this isn’t cooked over the stove for a long time, it retains that really bright fresh strawberry flavor. And unlike a freezer jam, the sun evaporates the moisture, concentrating the flavor and deepening the strawberry taste. It’s the best of all worlds!
The only tricky part is that you have to plan ahead and do this on a sunny day. And you’ll need a way to protect the Strawberry Sun Jam from bugs while it’s “cooking.” Some folks build little screen boxes, or wrap screen material around their pans, but we just put the pans in the back dash of our car and it works wonderfully.

Strawberry Sun Jam Recipe
12 cups fresh strawberries, green tops removed
3 cups organic cane sugar
1 cup light-colored honey
2 Tbs lemon juice
1/4 tsp sea salt
Start this jam in the morning, as you’ll need all the heat of the mid-day sun for this to finish!

Combine all the ingredients in large saucepan and heat over low to medium heat. Use a potato masher to smash and break up the strawberries while it heats- don’t pulverize them, but don’t leave them whole either.
Bring the strawberry mixture to a boil and allow it to gently boil for no more than five minutes.
Divide the strawberry sun jam mixture between two half sheet pans. I like these Commercial II 17X12 Jelly Roll Pans, which are also what I use for my every day cooking. This is important- if you put too much of the strawberry mixture on too small of pans, it will take too long and won’t finish properly. Large sheet pans with a lot of surface area are key.
Prepare your car! …I guess just make sure it’s reasonably clean and maybe wipe the dust off your dashboard. We set a clean bath towel on the dash to set the sheet pans on. Position the car so that the dash you’re using is facing the sun. The car windows should be kept closed.
Carefully transport the sheet pans outside and into your car- it will be hot so use oven mitts. It’s nice to have help for this step, as opening doors and getting into the car with a large pan can be awkward.

Alternately, you can position the empty sheet pans on the dash, bring the pot of hot strawberries outside, and ladle the strawberry mixture onto the pans while you’re inside the car. This will be awkward, but if you’re afraid you’ll spill on the trip outside, it’s a good option for you. Or set up a table outside your car and ladle onto the pans right outside your car, then it’s but a short distance to move them into the car.
Yes, this Jam is made in the Car!
I don’t know if this works with all types of cars, but we have a Chevy Impala with a traditional back dashboard and it holds two of my large pans perfectly. Might want to dry-run test if and where your pans fit in your car before doing this.
I’ve only used a hot car to make sun jam- if you’re using a different set up… like a wooden box covered with window screen, you’re on your own. Just keep in mind that it needs to be protected from both flying insects and crawling ones, especially ants! I’ve never had a problem with insects using the car method.
Also keep in mind that my “sunny day” in Wisconsin will be different than your “sunny day” in say, Arizona… so you’ll have to use your good senses depending on your location and adapt to your surroundings. My guess though, is that if the weather is nice enough to grow strawberries where you are, it’s probably also good for making jam.
Stir the Strawberry Sun Jam every 1.5 hours. Be careful, the pan will be extremely hot! Try to keep the pans level so that the strawberry sun jam isn’t too thin in places, otherwise those spots will finish faster and get too dry.
I found that on a full-sun day in the the heat of early Summer, this recipe took 4-5 hours of “cooking” in the sun to finish. Of course, there are a lot of factors at play here and your sun jam may take longer or shorter to finish.

How to Tell When the Jam is Done
The jam is done when it is thick, like the consistency of jam (go figure!), and has a glassy appearance. You can pull it when it’s to your liking, a little thicker, or thinner. It will seem thinner and looser in the hot car on the hot pan but will thicken quite a bit more once it cools, so keep that in mind when deciding when it’s done. If it’s your first time, I would err on the side of less done rather than over-cooking it.
If something happens that doesn’t allow you to finish your jam in one day… like a storm rolling in, or it’s just taking its sweet time, you can finish it in the oven, though I would avoid this if possible. Put your oven on the lowest setting and stir the jam every 20-30 minutes until it thickens to your liking.
Once it is finished, stir it up good and spoon the Strawberry Sun Jam into jelly jars. I love these tall 12oz Jelly Jars– they’re beautiful, the size is unique, and they’re also approved for freezing. In case you didn’t know, you shouldn’t freeze just any old jar. Only jars with straight sides and without shoulders should be put in the freezer, otherwise they can and will easily break.

This jam will last in the fridge for at least a couple months. It freezes wonderfully, so we keep our sun jam stash in the freezer.
If you want to make your jam extra fancy, I highly recommend Weck Jars– they’re stunning and they make me swoon… and they also can be frozen.
I can’t take the credit here- the original idea and recipe for strawberry sun jam comes from Amy Thielen, who is fantastically midwestern and an all around really cool lady, not to mention James Beard award-winning! Actually, she tells me that this recipe was originally her Grandma Addie’s! You can find her original recipe here!
I hope that you love this jam as much as we do- I know you will!
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I enjoy the cooking and canning part of making jam, but this is good to know! We made sun tea all the time when I was a kid. Makes sense that you can make jam in the sun, too!
This looks so incredible and fun to make! I haven’t made jam before because it’s always seemed like such a process but baking in my car sounds like a process I can get behind!
My mother did this w apricots as well leaving in the pots for the almond flavor. She would use a glass Pyrex 8×12” pan put toothpicks around the rum and place a sheet of glass on top. She would wipe off the liquid as it adhered to the glass. Bring it in at night and it would take about 3 days. Best ever!!!
This sounds like fun. Could this be made with other fruits than strawberry (and apricot as another commented noted)?
I have not tried apricot, but I have done raspberry and grape with success!
Would I be able to can this after?
No, this is for the freezer only.
Thank you for this recipe! Made it last year in my little ranger and loved it, however there isn’t a lot of space. Do you think it would work in the back of a Subaru? 🫣
Awesome! As long as it is in direct sun it should work. Just can’t be shaded at all.