This easy slow cooker spaghetti sauce simmers all day with tomatoes, vegetables, garlic, and Italian herbs for rich, homemade flavor. Makes a big batch so you can freeze the extras for quick and easy dinners later.
0 Heat the olive oil in a large skillet over medium heat. Add the onion, carrots, celery, and bell pepper. Cook for 7 to 10 minutes, stirring occasionally, until the vegetables have softened and the onion is translucent.
1 Add the minced garlic and cook for about 30 seconds, just until fragrant. Don't brown it.
2 Transfer the vegetables to a 6-quart slow cooker.
3 Add the San Marzano tomatoes, crushed tomatoes, tomato sauce, oregano, Italian seasoning, garlic powder, salt, and pepper. Crush the whole tomatoes with your hands as you add them, or break them up with a wooden spoon once they're in the Crockpot.
4 Stir everything together. Cover and cook on LOW for 8 hours.
5 Stir well and taste. Adjust the salt and pepper. Only add the brown sugar if the tomatoes still taste more acidic than you want, starting with a tablespoon.
6 Check the consistency. If it's thinner than you want, remove the lid and cook on HIGH for 30 to 60 minutes, stirring occasionally, until it reaches the consistency you like.
