All Day Tomato Sauce with San Marzano Tomatoes
This slow-cooked red sauce delivers a deep and authentic Italian flavor with just 5 basic ingredients. Make a big batch and freeze for easy meals!
or read on for step-by-step instructions with photos
The Ultimate Slow-Cooked Tomato Sauce
Every cook needs a go-to tomato sauce recipe in their arsenal. From quick weeknight marinara or authentic Italian pomodoro to the classic French mother sauce tomate, or even the kind you heat straight from a jar, there’s no shortage of options.
This sauce, though, is like no other. This is Italian-American red sauce—the kind that simmers all day, fills your kitchen with an irresistible aroma, and rewards you with a flavor that’s absolutely worth the wait.
This recipe is all about patience—allowing a handful of pantry staples to transform into something greater than the sum of their parts. With just five simple ingredients, you’ll create a rich, authentic red sauce that’s perfect for pasta, lasagna, or freezing for future meals.
What Makes This Recipe Unique
Few ingredients, big flavor: High-quality canned San Marzano tomatoes, garlic, olive oil, basil, and salt are all you need. The long cooking time brings out a depth of flavor without needing sugar, onion, butter, or any extra additives.
Slow-cooked perfection: Simmered for hours, this sauce develops a deep, complex flavor and a thick, velvety consistency.
Big batch efficiency: Since it takes time to make, this recipe is designed for batch cooking—perfect for freezing and future meals.
What’s Ahead in This Recipe
Pro Tips: How to enhance flavor, choose the best pot for slow-cooking, and choose the best canned tomatoes.
Serving Suggestions: Creative ways to use the sauce for pasta, lasagna, and more.
Customizations: Ideas for adding aromatics and spices without losing the simplicity of the recipe.
Storage Instructions: Tips for freezing and reheating so you always have homemade sauce on hand.
FAQs: Answers to common questions, like whether adding sugar is ever necessary, how to fix the consistency, and how to recover a burnt sauce.
This recipe takes time, but the result is worth every minute. Now, let’s get that sauce simmering!
What you’ll need
Ingredients
8 (28-ounce) cans whole peeled San Marzano tomatoes
1 head garlic, peeled and roughly chopped or crushed
1 cup extra virgin olive oil
1 bunch fresh basil, leaves torn or roughly chopped (stems reserved)
salt, to taste
Equipment
Large stainless steel pot (avoid reactive materials like aluminum or cast iron)
Wooden spoon
Hand masher (optional, for breaking up tomatoes)
Storage containers (for freezing or refrigerating leftovers)
Makes: 6 quarts/liters or 24 portions
Prep: 5 min Cook: 3 - 6 hours
How to make it
Step 1
Cook the garlic gently.
Add the olive oil to a large stainless steel pot over low heat. Gently cook the garlic, stirring occasionally, until it has softened completely—about 10 minutes.
Keep the heat on the lowest setting to ensure the garlic doesn’t pick up any color. The garlic is ready once it’s so soft that it disintegrates when pressed against the side of the pot.
💡 Pro Tip: Slow, gentle cooking allows the garlic to release its fat-soluble, flavorful compounds into the oil, creating a deeply aromatic base for the sauce. This step is crucial, so take your time—slow and low is the way to go!
Step 2
Add the tomatoes and cook.
Add the canned tomatoes, basil stems, and a few pinches of salt to the pot. Bring the sauce to a boil over high heat, then reduce the heat to the lowest setting to maintain a gentle simmer.
Cook uncovered, stirring occasionally, and use the back of a wooden spoon to press the tomatoes against the side of the pot to help break them down. For a smoother texture, you can also use a hand masher.
Simmer the sauce for a minimum of 3 hours, stirring every so often, until it thickens and fills your kitchen with an irresistible aroma. If time allows, let it cook for up to 6 hours (or longer!) for an even deeper flavor and a thicker consistency.
💡 Pro Tips:
Basil stems: Tie the basil stems together with butcher’s twine to create a bouquet that’s easy to take out at the end. If you don’t have twine, count how many stems you add to make sure you get them all later.
Extra flavor: Toss in a hard-cheese rind, like Parmesan or Pecorino, while the sauce simmers. It will soften but won’t fully melt, so you can easily take it out before serving.
Vegan option: Instead of a cheese rind, use 2–3 tablespoons of nutritional yeast for a plant-based alternative that adds extra depth and umami.
Step 3
Stir in the basil, season, and store.
Once your sauce has cooked and thickened to your liking, take it off the heat and stir in the fresh, torn basil leaves. Remove the basil stems and cheese rind, if using, and taste the sauce to adjust the seasoning with salt.
If you like, you can add a pinch of black pepper, but I prefer to keep the sauce simple and let the natural flavors shine. The long cooking time ensures the tomatoes’ sweetness balances the acidity, but if your sauce tastes too sour or you prefer it sweeter, feel free to add a pinch of sugar—I won’t judge!
Your sauce is now ready to use in pasta, lasagna, or any dish that calls for tomato sauce. Let the sauce cool completely before transferring leftovers to storage containers. If freezing, leave some space at the top of the container to allow for expansion.
💡 Pro Tip: I like to store my sauce in clear deli containers, using different sizes so I can easily grab only the amount I need.
My Tips
Don’t rush cooking the garlic: The garlic is the foundation of the sauce’s flavor, so take your time cooking it slowly over low heat.
This allows it to soften completely and release its flavorful aromatic compounds into the olive oil, infusing into the tomatoes as they cook together.
Hard cheese rind: Save hard cheese rinds, like Parmesan or Pecorino, in the freezer, then toss one into the sauce while it simmers. It adds a distinct savory, umami depth, just be sure to remove it before serving since it won’t fully melt into the sauce.
To keep the sauce vegan, substitute with a few tablespoons of nutritional yeast for a similar flavor boost.
Carrot for acidity: If you’re sensitive to acidity, adding a whole carrot while the sauce simmers can naturally balance the flavors without needing sugar. This old Italian kitchen hack helps balance acidity and subtly sweetens the sauce. Then remove before serving.
Use a non-reactive pot: Stick to stainless steel, ceramic, or enamel-coated cast iron pots when making tomato sauce.
Reactive materials like aluminum or un-enameled cast iron can interact with the acidity of the tomatoes, leaving a metallic or bitter taste in the sauce.
Taste multiple times: Seasoning is so important! Season your sauce throughout the cooking process to build flavor, then taste and adjust at the end with salt or even a pinch of sugar if needed.
Taste often—I sometimes adjust my sauce 20 times before I'm satisfied. This is how you achieve restaurant-quality results!
How to Choose the Best Canned Tomatoes?
D.O.P. San Marzano tomatoes are the gold standard for their sweetness, low acidity, and firm flesh. Grown in the volcanic soil of Italy’s San Marzano region, these tomatoes are certified with the Denominazione di Origine Protetta (D.O.P.) label, ensuring their authenticity and exceptional quality.
While highly prized by chefs and home cooks, you don’t need to break the bank or go on a wild goose chase to make an incredible sauce. Here are some great alternatives:
Top Choice: Try Bianco DiNapoli tomatoes, grown in California, these chef-favorite tomatoes are prized for their exceptional flavor and quality.
In Canada: I swear by the UNICO brand “San Marzano Type Tomatoes”—they taste great and are only a fraction of the cost of imported Italian brands.
U.S. Options: Many brands offer San Marzano-style tomatoes that replicate the flavor of D.O.P. tomatoes but are more budget-friendly. Look for options from Cento, Hunt’s, or Trader Joe’s, which are more widely available.
Regular Whole Peeled Tomatoes: If standard canned tomatoes are all you have, don’t worry! The long cooking time will enhance their flavor, and with a few adjustments at the end, you can still achieve a delicious sauce. If it tastes flat, add a splash of vinegar or, for overly acidic sauce, a pinch of sugar will balance it out.
Serving Suggestions
Pasta: Pair this sauce with classics like spaghetti, pappardelle, baked ziti, or even cheesy soft polenta. For a low-carb twist, try it with my easy grilled spaghetti squash.
Classic parmesan: Use this perfectly thick tomato sauce for topping chicken, veal, or eggplant parmesan.
Lasagna: Layer this tomato sauce along with creamy béchamel for an authentic Italian-style Lasagna. To learn the perfect layering technique, check out my meat lasagna recipe.
Meat sauce: Make a hearty meat sauce by browning ground beef with onions and garlic, adding a splash of red wine before simmering with the tomato sauce. I also love throwing in green peppers and mushrooms—it might not be traditional, but it’s so good!
Dip: Serve this sauce as a dip for crusty bread, garlic knots, or mozzarella sticks. It’s also amazing with a melty baked muffaletta—just scoop up the sauce with this classic New Orleans sandwich for a hearty appetizer or meal.
Braises: Use it as a flavorful base for braised dishes like turkey cacciatore or osso buco.
Meatballs: Simmer browned meatballs in the sauce until tender and serve over spaghetti or pile them onto a sandwich for the perfect meatball sub.
Sandwiches: Layer the sauce in Italian-style sandwiches along with my easy Mediterranean roasted veggies, fresh mozzarella, arugula, and balsamic vinaigrette on a ciabatta bun. Or, try it in a simple grilled cheese with pesto for a delicious red, white, and green variation.
Other pasta dishes you’ll love: If you’re craving pasta, try my creamy chicken fettuccine, smoky rigatoni amatriciana, or bison and mushroom tagliatelle. Unlike this slow-simmered sauce, these pasta dishes are quick, flavorful, and made in just one pot—perfect for a comforting meal when you’re short on time.
Substitutions
Herbs & spices: If you’d like to build a little more flavor, try adding dried oregano and chili flakes. Toast them in the olive oil for a couple of minutes after the garlic has softened before adding the canned tomatoes.
Keep it simple though—adding too many spices can detract from the sauce’s classic simplicity. At the end, you can stir in some chopped fresh parsley for brightness, but don’t skip the basil! Its unique flavor is essential and irreplaceable.
Slow cooker: To make this sauce in a slow cooker, use the sauté function to gently cook the garlic in olive oil until softened (about 10 minutes).
Add the canned tomatoes, basil stems, and salt, and cook on low for 6–8 hours or high for 3–4 hours, stirring occasionally.
Break down the tomatoes with the back of a wooden spoon or a hand masher as they cook.
Stir in fresh torn basil at the end and adjust the seasoning to taste.
Blend for smoothness: If you prefer a smoother sauce, blend with an immersion blender after taking out the basil stems (and cheese rind, if using) at the end.
Storage
Fridge: Let the sauce cool completely before transferring it to an airtight container. Store in the fridge for up to 5 days.
Freezer: Divide the sauce into portions and store in freezer-safe containers, leaving space at the top for expansion. Freeze for up to 3 months. To defrost, transfer to the fridge overnight or place the container in a bowl of water to thaw more quickly.
To Reheat: Warm the sauce gently over low heat on the stovetop or in the microwave. Add a splash of water if it has thickened, and stir occasionally to prevent sticking.
💡 Pro Tip: Portion the sauce into different serving sizes using clear deli containers so you can easily grab the amount you need. Label them with the date for easy tracking.
Dietary Notes: Gluten-free, Dairy-free, Egg-free, Vegan, Vegetarian, Low-carb
FAQs
Should I add sugar to homemade tomato sauce?
Italians will definitely say no, and I agree it’s not always necessary. A good tomato sauce shouldn’t need sugar since the long cooking time balances the acidity, especially if you’re using high-quality tomatoes that are naturally sweeter.
But if your sauce tastes too tangy, a small pinch of sugar can help—there’s no judgment here! Taste as you go, trust your instincts, and adjust to your preferences.
What if my homemade tomato sauce is too thick?
No problem! Just stir in a splash of water, homemade stock, or even a little pasta water until it reaches your desired consistency. Add it gradually so you don’t thin the sauce too much.
How do I fix tomato sauce that’s burnt?
If your sauce has scorched, don’t stir or scrape up any burnt bits off the bottom! Carefully transfer the unburnt sauce into a new pot, leaving the burnt layer behind. Then taste and adjust the seasoning. You may need to add a splash of vinegar or a pinch of sugar to mask any residual bitterness.
Why do I need to add so much oil to my tomato sauce?
The olive oil is essential for flavor—it carries the fat-soluble aromatic compounds in the garlic and basil, gives the sauce a silky texture, and balances the acidity of the tomatoes. Don’t skimp on it!
Why is there oil sitting on top of my sauce?
That’s totally normal! The oil can naturally separate when the sauce sits for a while or thickens too much. Just give it a good stir or add a splash of water, stock, or pasta water to re-emulsify the oil into the sauce.
What’s the difference between tomato sauce, red sauce, marinara, sugo, and pomodoro?
These terms are often used interchangeably, but they do have some key differences:
Tomato sauce: A general term for any sauce made with tomatoes.
Red sauce: Usually refers to a slow-cooked, Italian-American tomato-based sauce like this one.
Marinara: A quick, light tomato sauce made with garlic, olive oil, and herbs, cooked for about 30 minutes.
Sugo: An Italian term for sauce, often richer and cooked longer than marinara, but typically under 2 hours.
Pomodoro: A simple tomato sauce made quickly with fresh tomatoes and few other ingredients, often chunkier in texture.
Is tomato sauce one of the 5 French mother sauces?
Yes, tomato sauce is one of the five French mother sauces, though the French version is pretty different than this recipe. While this Italian-American red sauce emphasizes simplicity and slow cooking, the French version relies on a more complex list of ingredients and advanced techniques to build flavor.
Along with tomato sauce, four other sauces form the foundation of classical French cuisine. These mother sauces serve as bases for countless derivatives, or “daughter sauces,” used in a variety of classic dishes.
The five French mother sauces are:
Béchamel: A creamy white sauce made with milk and white roux.
Velouté: A light velvety sauce made with light stock (chicken, veal, or fish) and thickened with blond roux.
Espagnole: A rich brown sauce made with brown stock and brown roux.
Hollandaise: A warm emulsified sauce made with egg yolks, clarified butter, and an acid like lemon juice or vinegar.
Tomato: A French tomato sauce made with tomatoes, aromatics, salted pork, and sometimes thickened with roux.
That’s it, enjoy!
This sauce taught me the magic of simplicity. I first learned to make it as a line cook at an upscale diner in Toronto. Using just a few ingredients like in this recipe, we simmered the tomato sauce for hours to develop an incredible depth of flavor. It became the base for meatballs served with the simplest garlic bread—just toasted sourdough brushed with a little olive oil and rubbed with raw garlic. The combination was absolutely delicious.
It quickly became a household favorite. When I recreated it at home, my husband took it on as his project. Every few months, he’d make a big batch to freeze, filling the house with the intoxicating aroma of sauce simmering all day.
The perfect base for meat sauce. While it’s delicious on its own, I love turning it into a hearty meat sauce with ground beef, red wine, onions, fennel seeds, green peppers, and mushrooms. Tossed with rigatoni or pappardelle, it’s chunky, rich, and so flavorful, thanks to the already deeply simmered red sauce.
It’s a labor of love. No matter how you enjoy your tomato sauce, taking the time to make it is just as rewarding as eating it. Plus, having a few liters ready for future meals makes it all the more worthwhile.
Summary
Slow-Simmered Red Sauce with Canned San Marzano Tomatoes
Made with just 5 pantry staples, this red sauce simmers all day, delivering rich, authentic flavor. Perfect for pasta, lasagna, or freezing for effortless meals.
Makes: 6 quarts/liters or 24 portions
Prep: 5 min Cook: 3 - 6 hours
Ingredients
8 (28-ounce) cans whole peeled San Marzano tomatoes
1 head garlic, peeled and roughly chopped or crushed
1 cup extra virgin olive oil
1 bunch fresh basil, leaves torn or roughly chopped (stems reserved)
salt, to taste
Instructions
Cook garlic. Heat olive oil in a large stainless steel pot over low heat. Add garlic and cook gently, stirring occasionally, until softened—about 10 minutes. Keep the heat low to prevent browning.
Simmer sauce. Add canned tomatoes, basil stems, and a few pinches of salt to the pot. Bring to a boil over high heat, then reduce to a gentle simmer. Cook uncovered for at least 3 hours, stirring occasionally. Use the back of a spoon or a hand masher to break down tomatoes. Simmer for up to 6 hours for even deeper flavor.
Finish and serve or store. Once the sauce has thickened, remove from heat and stir in the torn basil leaves. Remove basil stems, then taste and adjust the seasoning with salt. Let the sauce cool completely before transferring to storage containers. Leave space at the top if freezing.
Top Tips
Basil stems: Tie the basil stems with butcher’s twine to create a bouquet that’s easy to remove. If you don’t have twine, just count the stems you add to make sure you don’t leave any behind.
Extra flavor: Add a hard-cheese rind, like Parmesan or Pecorino, while the sauce simmers. It will soften but won’t fully melt, so you can remove it before serving. For a plant-based alternative, use 2–3 tablespoons of nutritional yeast to add depth and umami.
Use a non-reactive pot: Always use stainless steel, ceramic, or enamel-coated cast iron pots when making tomato sauce. Reactive materials like aluminum or uncoated cast iron can interact with the tomatoes’ acidity and leave a metallic or bitter taste.
Further reading: Explore more in my tips, serving suggestions, substitutions, storage, and FAQs sections!
I love hearing from you! If you’ve tried this recipe, please leave a comment below and let me know how it turned out.
Enjoy!
