Spaghetti Marinara From Scratch With San Marzano Tomatoes

Spaghetti Marinara is what I make when I want dinner to feel effortless but taste nothing like it. The whole dish rests on the sauce, and the sauce rests on the tomatoes.

Good San Marzano tomatoes simmered slowly with onion, garlic, oregano, and a little red pepper flake give you something far brighter and rounder than a jar. Pantry ingredients, one unhurried simmer, and most of that hour’s hands-off.

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Why You’ll Love This Recipe

• The flavor comes almost entirely from letting San Marzano tomatoes simmer down, not from a long shopping list, so everyday ingredients do the work of a much more complicated sauce.
• Once the sauce is at a low simmer, it looks after itself for the better part of an hour, which leaves you free to cook the spaghetti, lay the table, or get a head start on the cleanup.
• The sauce is the part you can make ahead. I think it is better the day after, and a batch sitting in the fridge turns a weeknight dinner into a ten-minute job.
• It works for one quiet dinner and for a full table without changing anything but the quantities. That is how it became a weeknight regular in my kitchen rather than a someday recipe.

Ingredients You’ll Need

You’ll need all the ingredients shown in the photograph below.

• San Marzano plum tomatoes. These are the backbone of the dish. They are sweeter, lower in acidity, and carry fewer seeds than an ordinary canned plum tomato, so the finished sauce reads rounded rather than sharp. Canned whole ones are the right call here, since they are picked and packed at peak ripeness. Look for the DOP seal on the can if you can find it, though a good standard San Marzano works too.
• Onion and garlic. Finely chopped onion and fresh garlic build the savory base under the tomatoes. Chop the onion small so it melts into the sauce over the long simmer instead of staying in noticeable pieces.
• Dried oregano and red pepper flakes. Oregano is the herb that reads as classic Italian tomato sauce, and the half teaspoon of red pepper flakes adds a low background warmth rather than real heat. Keep the flakes where the recipe card has them unless you already know you want more.
• Olive oil. Three tablespoons go in with the seasonings. For a rounder, more peppery finish, a good extra-virgin olive oil is worth using here over a plain one.
• Spaghetti. Sixteen ounces, enough for four. Buy a brand you like, since with these simple ingredients the pasta itself is doing real work. Gluten-free spaghetti stands in fine if you need it.
• Fresh basil and Parmesan, to finish. Both are optional, but I would not skip them. A few torn basil leaves and a shower of vegetarian or vegan Parmesan are what pull the bowl together at the table. Standard Parmesan is made with animal rennet, so check for a vegetarian version if that matters to you.

How to Make Spaghetti Marinara

A complete printable recipe and the measurements in both US customary and metric are available in the recipe card below.

Build the Marinara Base

Add the San Marzano tomatoes to a medium saucepan or a Dutch oven, then the onion and garlic. If you are working from fresh tomatoes rather than canned, break them down first with a food processor or a potato masher so they cook down evenly.

An enameled cast-iron Dutch oven holds a steady low simmer over a long stretch without scorching the bottom.

Season and Simmer

Add the oregano, red pepper flakes, and olive oil, and stir to combine thoroughly. Bring the pan to a simmer over medium heat, then lower the heat and leave it to simmer for the full 45 minutes, stirring now and then.

This is the part not to rush. That unhurried simmer is what turns raw ingredients into something deep and fragrant, and cutting it short leaves the sauce thin and underdeveloped. If it tastes a little sharp at the end, a small pinch of sugar balances the acidity, though with good San Marzano tomatoes you often won’t need it.

Cook the Spaghetti

While the sauce finishes its simmer, cook the spaghetti in a large pot of well-salted boiling water, following the packet directions and stirring in the first couple of minutes so the strands do not stick. Start it so it comes off the heat around the time the sauce does. Pull it while it’s still just al dente, since it keeps softening once it meets the hot sauce.

Combine and Coat

Move the drained spaghetti straight into the sauce and toss until every strand is covered. If a little pasta water rides along with it, so much the better; that starchy water helps the sauce cling to the pasta rather than pool at the bottom of the bowl.

Finish with a handful of torn fresh basil and a generous shower of vegetarian or vegan Parmesan, then serve straight away while it’s hot.

To get ahead, make the sauce up to a day before. Cool it in a shallow container, refrigerate it within two hours, and it keeps for 3 to 4 days before you cook fresh pasta to go with it.

Recipe Notes and Expert Tips

• Use whole San Marzano tomatoes. They are less acidic and naturally sweeter than standard canned tomatoes, which is what gives the sauce its depth without any help from tomato paste.
• Don’t cut the simmer short. The full 45 minutes over low heat is what develops the flavor and thickens the sauce enough to coat the pasta. Stop early, and you are left with something thinner and flatter.
• Salt the pasta water properly. The water is your only chance to season the spaghetti itself, so be generous. It should taste like a light broth, not the sea and not plain.
• Let the pasta water work for you. When you lift the spaghetti into the sauce, a little of that starchy water comes with it, and the starch is what helps the sauce bind to each strand. Don’t chase every last drop off the pasta before it goes in.
• Toss for a full minute before serving. Work the spaghetti through the sauce in the pan so it is coated all the way through, not just dressed on top once it hits the bowl.

Recipe Variations

• For more heat, push the red pepper flakes up or slice a fresh chili in with the onion and garlic. It is a tested change I make often, and it costs the dish nothing. If real fire is what you want, my spicy penne arrabiata is the one to cook next, a quick garlic-and-chili tomato pasta from the same Italian family that I have made many times.
• Gluten-free is a tested, straight swap to your favorite gluten-free spaghetti. The sauce has no gluten in it, so nothing else changes, and I make it this way without hesitation.
• To turn it into a fuller vegetable dinner, fold sautéed mushrooms or roasted vegetables into the sauce near the end. This is a supported variation that shifts the bowl toward something heartier; it is the change I make when I want more on the plate.
• Leftover sauced spaghetti also bakes well. Tip it into a dish, top with cheese, and bake until bubbling, much the way my vegetable pasta bake comes together. I have not timed that exact move from these leftovers, so treat it as untested and watch it rather than setting a clock.

How to Store Leftovers

Divide leftovers into shallow containers and refrigerate promptly, within two hours of cooking, rather than cooling them fully on the counter first. To reheat, warm gently in a pan over low-medium heat with a splash of water so the sauce loosens instead of seizing.

For the freezer, keep the sauce on its own rather than the assembled dish, since spaghetti frozen in sauce turns soft. Store the finished dish in the fridge for 3 to 4 days, or freeze the sauce on its own for up to 1 month and pair it with freshly cooked pasta.

What to Serve With Spaghetti Marinara

Warm, crusty garlic bread is the pairing I want first, purely so there’s something to mop up the last of the San Marzano sauce left in the bowl. Alongside it, I like a crisp green salad with a light vinaigrette to cut against the rich pasta.

If you want a fuller spread, roasted vegetables like zucchini, eggplant, or bell peppers sit well on the side, and plant-based meatballs keep it hearty and familiar. And if you are building a bigger pasta night, put it out next to a second bowl like my Boursin cheese pasta so people can take a little of each.

FAQs

More Easy Pasta Recipes to Try

A few more pasta dinners from my kitchen I think you will get real use out of.

• Vegan spaghetti bolognese. Where I go when I want something heartier on the same spaghetti base, built on lentils and mushrooms for real depth.
• Vegetarian lasagna. My pick when the occasion calls for something to carry to the table whole and let people dig into.
• Pasta primavera. The one for a lighter, vegetable-packed night when the red-sauce version feels like too much.
• Lemon pasta. What I make on the busiest nights, bright and quick with barely anything in it.