I always have an abundance of tomatoes at the end of gardening season. I stay very busy at the end of gardening season as well with back to school and fall events so I appreciate this no peel slow cooker marinara recipe that allows me to use my tomatoes with minimal effort!
This recipe cooks for a total of 8 hours on high in the slow cooker (with one required stir). Most recipes in the slow cooker don’t cook on high for that long, but it is necessary with the marinara.
Most marinaras will have a long, slow simmer on the stove to concentrate the tomatoes and we are trying to duplicate that in a slow cooker. It takes both time and heat or your marinara will end up watery.
That being said, water content of the tomatoes will make a difference too. Plum tomatoes are by far the best for this recipe because of their low moisture content, but that might even vary. In short, you may need more or less time depending on your tomatoes.
Tips and Tricks for the No Peel Slow Cooker Marinara recipe:
- Layer in your slow cooker. The onions need to go on the bottom to saute, while the tomatoes don’t. This layering helps to cook different food items appropriately.
- No need to core or peel. We will be using an immersion blender to blend the sauce smooth. The smoother you make your marinara, the better the chances you won’t have leftover bits of skin in the final product. If you want chunky marinara, you should plan on the extra steps of peeling and coring.
- Watery results. If your marinara looks watery at the end of the cooking time, take the lid off and let it simmer for another 30 minutes to an hour so that some water can evaporate. A thinner marinara can still be great for any recipe that further cooks the marinara, such as lasagna, stuffed shells, or Italian polenta pie.
- Plum tomatoes are king. They are thick and meaty and not too juicy. This will help greatly in concentrating the sauce without extra cooking time. Romas are the most common variety.
- 1 large yellow onion, diced
- 8 garlic cloves, coarsely minced
- 6 oz can tomato paste
- ¼ cup olive oil
- 2 TBS balsamic vinegar
- 1 TBS sugar, honey, or agave
- 2 tsp dried basil
- 1 tsp each: oregano, thyme, and salt
- ¼ tsp crushed red pepper flake
- 1 bay leaf
- 5 lbs plum tomatoes, such as roma
- In a 6 quart slow cooker, combine the onion, garlic, tomato paste, olive oil, balsamic, sugar, basil, oregano, thyme, salt, and crushed red pepper flake, stirring to combine. Top with the bay leaf.
- Split the tomatoes in half crosswise. Squeeze out the seeds (it’s ok if some are missed) into a bowl or fine strainer with a bowl underneath. Cut any large halves in half again (smaller tomatoes don’t need cut again). Place in the slow cooker on top of the onion mixture and do NOT stir. Cover and cook on high for 3 hours.
- Stir the content of the slow cooker. Find and remove the bay leaf. Use an immersion blender to puree the mixture until smooth (lumps could be tomatoes with skin, so smooth is best).
- Cover and cook again for 5 hours on high or until thickened. Taste test and add more salt as necessary.
- Refrigerate for up to 5 days or freeze for up to 6 months. Makes approximately 9 cups, or just over 2 quarts.
Recipe adapted from Eating Well.
