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Keto Spaghetti Sauce Recipe

Dom Lorenzo
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Looking for a flavorful, low-carb pasta sauce to complement your keto noodles? This Keto Spaghetti Sauce Recipe is the perfect match! Made with fresh tomatoes, herbs, and keto-friendly ingredients, this sauce is rich, hearty, and free from added sugars. Pair it with zoodles, shirataki noodles, or keto pasta for a delicious meal that keeps you on track with your low-carb goals.

Keto spaghetti sauce in a cast iron pot, with a ladle scooping up a portion.
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Preparation and Cooking Overview

Dice the onion and mince the garlic, then sauté them in olive oil until fragrant. Stir in tomato paste to enhance depth, followed by crushed tomatoes and seasonings. Let the sauce simmer uncovered for 20–25 minutes, adjusting consistency with water if needed, then finish with fresh herbs.

Chef's note

The key to a great low-carb spaghetti sauce is using tomatoes with no added sugar and balancing their acidity with the right herbs and seasonings. If you want a heartier sauce, add ground beef, Italian sausage, or ground turkey for extra protein. Adjust the heat by increasing or omitting red pepper flakes to suit your spice preference.

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  • Prep Time: 10 minutes
  • Cooking Time: 25 minutes
  • Total Time: 35 Minutes
  • Difficulty Level: Easy
  • Recipe Makes 4 Servings

Ingredients for This Keto Spaghetti Sauce Recipe

  • 2 tablespoon olive oil
  • 1 small onion, diced
  • 4 cloves garlic, minced
  • 1 (28 oz) can of crushed tomatoes (no added sugar)
  • 1 tablespoon tomato paste
  • ½ teaspoon dried oregano
  • ½ teaspoon dried basil
  • ½ teaspoon dried thyme
  • ¼ teaspoon red pepper flakes (optional for heat)
  • Salt and black pepper to taste
  • ½ cup water (optional, for adjusting consistency)
  • Fresh basil or parsley for garnish (optional)

Ingredient Substitutions

  • Tomato paste: Sun-dried tomato puree adds a richer, slightly sweeter depth to the sauce, enhancing the umami flavor without added sugar.
  • Dried oregano, basil, and thyme: You can use fresh herbs instead of dried ones by tripling the amount, as fresh herbs provide a more aromatic and vibrant taste.
  • Garlic: Swap it with garlic powder (½ teaspoon per clove) if fresh garlic isn’t available.

Additional Ingredients

Want to customize your sauce? Here are some keto-friendly add-ins:

  • Sautéed mushrooms: It bring an earthy, slightly chewy texture that adds depth and complements the tomato base.
  • Parmesan cheese: It enhances the sauce with a rich, umami depth and a slight creaminess that balances the acidity of the tomatoes.
  • Ground beef or Italian sausage: It adds a hearty texture and savory depth, making the sauce more satisfying and protein-packed.
  • Balsamic vinegar (sugar-free): It introduces a touch of sweetness and acidity, helping to balance the tomatoes’ tartness and enhance overall flavor complexity.
  • Anchovy paste: It boosts umami without making the sauce taste fishy, creating a richer and more complex depth of flavor.

Cooking Tools Required

  • Cast Iron Pot
  • Wooden spoon or spatula
  • Measuring cups and spoons
  • Cutting board and knife

Tool Substitute Options

  • Cast Iron Pot: A deep skillet, large saucepan, or Dutch oven will work just as well.

How to Make Keto Spaghetti Sauce: Step-by-Step Guide

Cooking methods

  • Sautéing
  • Simmering

Preparation Steps

  1. Dice the onion and mince the garlic.
  2. Measure out all your herbs and spices for easy access.

Cooking Instructions

  1. Heat the olive oil in a cast iron pot over medium heat.
  2. Sauté the onion for 3–4 minutes until soft and translucent.
  3. Add minced garlic and cook for 1 more minute, stirring frequently.
  4. Stir in the tomato paste and cook for 3–4 minutes (this helps reduce acidity).
  5. Add crushed tomatoes, oregano, basil, thyme, and red pepper flakes. Stir well.
  6. Bring to a gentle simmer, then reduce heat to low. Cook uncovered for 20–25 minutes, stirring occasionally.
  7. Adjust consistency with water, if needed.
  8. Season with salt and pepper to taste.
  9. Garnish with fresh basil or parsley before serving.

Chef's pro tip

Cooking the tomato paste for a few minutes before adding the crushed tomatoes helps bring out its sweetness and mellow the acidity. If the sauce still tastes a bit too tangy, a pinch of baking soda or a little sugar-free sweetener can help balance the flavors. Letting it simmer uncovered also helps thicken the sauce and deepen the taste.

What to Serve with Keto Spaghetti Sauce

  • Keto noodles: Serve over zucchini noodles (zoodles), shirataki noodles, or spaghetti squash for a low-carb pasta experience.
  • Meat dishes: Use this sauce as a topping for grilled chicken, meatballs, or Italian sausage to add flavor and moisture.
  • Cheesy bakes: Layer it in keto lasagna with cheese and low-carb noodles or bake it with stuffed peppers or eggplant.
  • Bread alternatives: Dip with keto garlic bread, chaffles, or almond flour biscuits for a satisfying meal.
  • Egg-based dishes: Drizzle over baked eggs or shakshuka for a savory, tomato-rich breakfast or brunch.

How to Make It Healthier

  • Use more fresh vegetables like zucchini or bell peppers for extra nutrients.
  • Add bone broth instead of water for more nutrients and depth of flavor.

Time-Saving Tips

  • Use pre-chopped onions and pre-minced garlic to speed up prep time.

What Can I Prepare Ahead of Time?

  • Chop the onions and garlic ahead of time and store them in the fridge.
  • Make the sauce in bulk and store it in portions for easy meal prep.

Storage and Reheating Instructions

Storage Instructions

  • Store in an airtight container in the fridge for up to 5 days.
  • Freeze in portioned freezer-safe bags or containers for up to 3 months.

Best Reheating Instructions

  • Stovetop: Heat in a saucepan over medium-low heat, stirring occasionally.
  • Microwave: Heat in 30-second intervals, stirring in between.
  • Frozen sauce: Let thaw overnight in the fridge before reheating.

Recipe Wrap-Up and Conclusion

This keto spaghetti sauce is simple, delicious, and packed with classic Italian flavors without the extra carbs. Whether you pair it with zoodles, shirataki noodles, or keto-friendly pasta, it’s a perfect low-carb option for any meal. Make a batch today and enjoy homemade goodness without the sugar!

Frequently asked questions

You can thicken keto spaghetti sauce without adding carbs by simmering it uncovered to let excess water evaporate. Another option is adding tomato paste (which is naturally low in carbs) or blending some of the sauce to create a thicker consistency. Xanthan gum, a keto-friendly thickener, can also be used sparingly.

Yes, spaghetti sauce can be keto-friendly if it is made without added sugars and high-carb ingredients. This recipe uses fresh or canned tomatoes (no sugar added), olive oil, and herbs, making it a great low-carb option. Always check labels if using store-bought sauce to ensure it meets keto guidelines.

Keto-friendly pasta alternatives include zucchini noodles (zoodles), shirataki noodles, spaghetti squash, and low-carb pasta made from almond or coconut flour. These options help keep carb intake low while still offering a satisfying pasta-like experience.

Traditional wheat-based spaghetti is high in carbs and not suitable for keto. However, you can enjoy spaghetti substitutes like shirataki noodles, zucchini noodles, or keto-friendly pasta made from alternative flours to stay within your carb limits.

Keto-friendly sauces include homemade or store-bought options that are free of added sugars and starches. Marinara, alfredo, pesto, and butter-based sauces with herbs and spices are great choices for a keto diet. Always check ingredients to avoid hidden sugars.

Shirataki noodles (also known as konjac noodles) have the lowest carb count, with nearly zero net carbs. Other low-carb options include zucchini noodles, spaghetti squash, and homemade keto pasta made from almond flour or egg-based recipes.

No, tomatoes contain natural sugars and carbs, so they should be consumed in moderation on a keto diet. A small amount, such as in this sauce recipe, is fine, but excessive consumption may increase carb intake beyond keto limits.

📖 Recipe

Keto spaghetti sauce in a cast iron pot, with a ladle scooping up a portion.

Keto Spaghetti Sauce

This sauce is a rich, hearty, and low-carb alternative to traditional pasta sauces, made with fresh tomatoes, herbs, and no added sugar.
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Course: Sauce
Cuisine: Italian
Prep Time: 10 minutes
Cook Time: 25 minutes
Total Time: 35 minutes
Servings: 4
Calories: 82kcal

Ingredients

  • 2 tablespoon olive oil
  • 1 small onion diced
  • 4 cloves garlic minced
  • 1 28 oz can crushed tomatoes (no added sugar)
  • 1 tablespoon tomato paste
  • ½ teaspoon dried oregano
  • ½ teaspoon dried basil
  • ½ teaspoon dried thyme
  • ¼ teaspoon red pepper flakes optional for heat
  • Salt and black pepper to taste
  • ½ cup water optional, for adjusting consistency
  • Fresh basil or parsley for garnish optional
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Instructions

Preparation Steps

  • Dice the onion and mince the garlic.
  • Measure out all your herbs and spices for easy access.

Cooking Instructions

  • Heat the olive oil in a cast iron pot over medium heat.
  • Sauté the onion for 3–4 minutes until soft and translucent.
  • Add minced garlic and cook for 1 more minute, stirring frequently.
  • Stir in the tomato paste and cook for 3–4 minutes (this helps reduce acidity).
  • Add crushed tomatoes, oregano, basil, thyme, and red pepper flakes. Stir well.
  • Bring to a gentle simmer, then reduce heat to low. Cook uncovered for 20–25 minutes, stirring occasionally.
  • Adjust consistency with water, if needed.
  • Season with salt and pepper to taste.
  • Garnish with fresh basil or parsley before serving.

Nutrition

Nutrition Facts
Keto Spaghetti Sauce
Amount Per Serving
Calories 82 Calories from Fat 63
% Daily Value*
Fat 7g11%
Saturated Fat 1g6%
Polyunsaturated Fat 1g
Monounsaturated Fat 5g
Sodium 37mg2%
Potassium 103mg3%
Carbohydrates 5g2%
Fiber 1g4%
Sugar 2g2%
Protein 1g2%
Vitamin A 109IU2%
Vitamin C 4mg5%
Calcium 24mg2%
Iron 1mg6%
*

Nutritional values are estimates only and do not include carbs from sugar alcohols.

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