Slow Roasted Tomatoes

This post will show you how to make Slow Roasted Tomatoes, which I think are one of the best things about summer! And be sure to check out the recipe ideas using roasted tomatoes included in the post!

PIN this to make Slow Roasted Tomatoes later!

Slow Roasted Tomatoes are a must-make treat if you have a garden, or even access to a farmer’s market where you can get good fresh tomatoes. I first learned about slow roasted tomatoes when I was just starting to read food blogs.

Suddenly it seemed like everyone was making roasted tomatoes, including my friend Alanna, who tried lots of variations and posted the master recipe which I (mostly) followed here. For years I had made tomato sauce and frozen it to use all winter in soups, stews, and pasta sauce. But I hadn’t ever made roasted tomatoes.

This post will show you what I did to get those lovely looking roasted tomatoes you see in the photo above. And I’m going to be turning the tomatoes into pasta salad with roasted tomatoes on Thursday, when some special guests are coming for dinner.   I usually make several trays of these at a time, because they do require a long time in the oven, so do that if you can. But for those who don’t have so many tomatoes I’m giving the base recipe that uses 20 tomatoes, enjoy!

And here’s a nice tribute to my slow roasted tomatoes from the early days of food blogging! 

What ingredients do you need for this recipe?

(This is only a list of ingredients; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe with ingredient amounts.)

• Roma type tomatoes (same size tomatoes are best if your garden cooperates)
• olive oil
• Ground Fennel (affiliate link)
• Dried Basil (affiliate link)
• Dried Oregano (affiliate link)
• Dried Marjoram (affiliate link) 
• (Any combination of herbs that appeals to you can be used.)

How high in carbs are the Slow Roasted Tomatoes?

Even though this is an old recipe from the early days of my blog, I want to give nutritional info for current readers. Of course, these concentrated tomatoes are quite high in carbs. But luckily it doesn’t take many to add intense tomato flavor. Two roasted tomatoes have about 7 net carbs, with 2 grams of protein.

Starting the process for Slow Roasted Tomatoes:

(This is only a summary of the steps for the recipe; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe.)

1. If possible, use a Roma type tomato for best flavor. You need about 20 tomatoes to fill a cookie sheet .
2. Cut the tomatoes in half, leaving the stem piece whole.
3. I tossed the tomatoes with olive oil, ground fennel, dried basil, dried oregano, and dried marjoram.
4. I sprayed the cookie sheet with an olive oil mister, then arranged the tomatoes cut-side down on the cookie sheet. I had pre-heated the oven to 250F. (see recipe notes.)
5. After 3 hours, the skins of the tomatoes are just starting to wrinkle up a bit, and the house is starting to smell tomatoey.

Finishing the Slow Roasted Tomatoes:

1. After six hours, the tomatoes are considerably more shriveled looking.
2. After two more hours, the smaller tomatoes are done. I took the tomatoes out, let them cool a bit, and pinched off the skins. Most of the skins came off easily. Leave the water running to rinse your hands.
3. I turned the larger tomatoes over and put them back in the oven for one more hour.
4. This round bowl 5 1/2 inches across and 2 1/2 inches high is how many tomatoes I got (minus a few that I ate!) The tomatoes taste like a month of summer experienced in one day.
5. Last year I didn’t make enough roasted tomatoes and ran out long before winter was over! And if you’re going to use the oven this long to make roasted tomatoes I recommend making as many as you can fit in the oven!

How to use Slow Roasted Tomatoes:

• Use slow roasted tomatoes (in a smaller amount) in any soup or stew recipe where you’d use canned roasted tomatoes.
• The roasted tomatoes are delicious chopped, tossed with freshly cooked pasta with a bit of olive oil, some fresh basil, and freshly grated parmesan cheese.
• Slow Roasted tomatoes would be an amazing ingredient to add to pasta salad or marinated vegetable salad.
• The slow roasted tomatoes were great in Roasted Tomato Hummus.

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5.0 Stars (2 Reviews)

Yield: 20 roasted tomatoes

Slow Roasted Tomatoes

Prep Time 20 minutes

Cook Time 9 hours

Total Time 9 hours 20 minutes

I think Slow Roasted Tomatoes are one of the best things about summer! The long cooking time at a low temperature concentrates the tomato flavor in a remarkable way.

Ingredients

• 20 Roma type tomatoes (same size tomatoes are best if your garden cooperates)
• 2 T olive oil, plus a little to oil the pan if you don't have a mister
• 1 T ground fennel
• 2 T dried basil
• 1 T dried oregano
• 1 T dried majoram (Any combination of herbs that appeals to you can be used.

Instructions

1. Preheat oven to 250 F (about 9 hours roasting time) or 200 F (10-11 hours roasting time.) I used the shorter time, but mainly because my antique oven will not stay at 200 F.
2. Wash tomatoes, dry, and cut each tomato in half lengthwise, keeping the stem spot in one piece (to grab when peeling the tomatoes later.)
3. Put tomatoes in a bowl and toss with olive oil and herbs.
4. Spray cookie sheet with olive oil mister (or brush very lightly with oil).
5. Arrange tomatoes cut-side down on cookie sheet.
6. After about 8 hours, start checking tomatoes. They're done when skins puff up and tomatoes are reduced in size by at least half. It's a personal preference as to how dried you like them, and I prefer to cook mine until they look fairly dense, but still a tiny bit juicy.
7. These Slow Roasted Tomatoes have an intense tomato flavor that you probably can't get any other way. They can be eaten hot or cold.
8. The tomatoes freeze wonderfully to use all winter in soups, stews, and pasta sauces.

Notes

I definitely made these Slow Roasted Tomatoes before people became more energy conscious, and you may not want to turn on the oven for such a long time these days. I haven't tried roasting the tomatoes at a higher temperature or in the Air Fryer for a shorter time, but I think it would be worth trying.

I am considering two tomatoes to be a serving for nutritional information for this recipe, because Slow Roasted Tomatoes are mostly used in small amounts to flavor a recipe.

Nutrition Information

Yield

10

Serving Size

1
Amount Per Serving Calories 84Total Fat 5gSaturated Fat 1gTrans Fat 0gUnsaturated Fat 4gCholesterol 0mgSodium 14mgCarbohydrates 10gFiber 3gSugar 7gProtein 2g

Nutrition information is automatically calculated by the Recipe Plug-In I am using. I am not a nutritionist and cannot guarantee 100% accuracy, since many variables affect those calculations.

Did you make this recipe?

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Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
Slow Roasted Tomatoes are definitely high in carbs, so they’re an ingredient to use sparingly if you care about carbs. I would try to combine them with other low-carb ingredients if you’re following the South Beach Diet or another low-carb eating plan.

Find More Recipes Like This One:
Use Tomato Recipes or Cooking for Gardeners to find more recipes like this one. Use the Diet Type photo index pages to find more recipes suitable for a specific eating plan. You might also like to follow Kalyn’s Kitchen on Pinterest, on Facebook, on Instagram, on TikTok, or on YouTube to see all the good recipes I’m sharing there.

Historical Notes for this Recipe:
This recipe about making Slow Roasted Tomatoes was posted in 2006, in the early days of my blog when food bloggers would find and try recipes from other bloggers. That was also a time when passionate cooks didn’t think twice about using the oven all day long to make wonderful-tasting slow roasted tomatoes! The recipe was last updated with more information in 2026.