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The Science of Cooking the Perfect Pasta

Ask anyone who just tried to make Spaghetti Cacio e Pepe or Pasta alla Carbonara for the first time how their dishes came out—and you’ll quickly come to the conclusion that the simplest recipes in Italian cuisine are also the hardest ones to cook.

Most pasta recipes can be surprisingly hard to get right if you don’t really know what you’re doing (and why you’re doing it in the first place). It can also be exceptionally rewarding if you know the basic science behind cooking pasta and use it to inform your cooking.

Which is exactly what I aim to help you achieve by the time you’re finished reading this article. I want you to know what works and what doesn’t, so that you can separate scientific fact from cooking fiction and equip yourself with the know-how you need to make perfect pasta every single time.

So what’s the science of cooking the perfect pasta? Here’s the long story short of what I’m about to share with you in the rest of this article:

Use bronze-cut pasta made of 100% semolina flour. Cook the noodles al dente in generously salted water that you’ve brought to a rolling boil. Sauce the pasta correctly by mixing it with your sauce and continuing to cook it for 1 minute before serving it on a plate.

If you want to know how each of these steps contributes to the perfect pasta, keep on reading.

Use Bronze-Cut Pasta Made of 100% Semolina Flour

Dried pasta is made from two ingredients: flour and water. Simply said, the higher-quality the flour, the better-tasting the pasta. And the best flour for pasta is semolina flour, a coarsely-ground Italian flour made from durum wheat.

Semolina flour has a coarse texture, golden color, and a higher protein content (12-13%) compared to all-purpose flour (9-10%). The higher the protein content of a flour, the more elastic and chewier the dough, which is what makes semolina flour so fit for pasta dough.

Pasta noodles made of 100% semolina flour have a golden color, coarse texture, and hold on to their shape really well when cooked. This makes pasta dishes made with semolina-flour pasta more appetizing.

The dried pasta that you and I buy in the grocery store is made on a large scale in commercial pasta machines at pasta factories. Pasta machines mix and knead the dough, then extrude and cut it through molds called “dies.” Different dies produce different shapes and forms of pasta.

The material that the dies are coated with is important for the overall quality of the pasta. In general, pasta makers coat their dies with one of two materials: bronze or non-stick. Bronze is the more traditional material, but it’s also more expensive to own, use, and care for. Non-stick is more modern material that’s less expensive to operate and maintain.

Bronze-cut pasta is better than non-stick-cut pasta because as a material, bronze has a more porous and imperfect surface. Pasta noodles extruded through bronze dies have a rougher surface, which allows sauces and bits and pieces of meat or vegetables to cling better to them, which results in more taste in every bite.

Whenever you can, buy bronze-cut pasta noodles made of 100% semolina flour. The good news is that you can find them in most grocery stores. You just need to know what brands and products to look for. Check out my list of the best Italian pasta brands to learn more.

Bring the Pasta Water to a Rolling Boil

Pasta noodles should be cooked in a pot of water brought to a rolling boil.

“Food responds best when it comes into sudden contact with something hot,” New York Times food author Mark Bittman writes in his 1998 book, How to Cook Everything.

“Whether you’re plunging spaghetti into boiling water or a steak into a hot skillet, this heat impact is what will get you tender (not mushy) pasta and a crisp brown crust on your steak.”

A “rolling boil,” also known as a “full boil,” is when water gets heated to its boiling point of 212°F (100°C). At this stage, the water will start to give off plenty of steam and bubbles will start to appear, roll around, and burst quickly and randomly on its surface.

To get a rolling boil, fill your pot with tap water and put it over high heat on your stovetop. After 3-4 minutes, the water should start to steam, bubble, and churn.

By this point, your pot of water should be at a rolling boil (and should therefore be ready to boil the pasta noodles in).

Salt the Pasta Water Before Adding the Noodles

As a saying among Italian chefs goes, “pasta water should taste like the sea.” Since most of you probably don’t taste seawater for a living, here’s what salt does to your pasta—and how much of it you should add to the pot of water.

Pasta noodles are made of pasta dough, which consists of semolina flour, water, and, occasionally, eggs. Pasta dough doesn’t contain salt, which is why your pasta will come out tasting bland unless you cook it in generously salted water.

“It is not possible to ‘season up’ undersalted pasta once it is cooked,” food author Michele Romano says in the 2005 edition of The Cook’s Book. “The salt will not penetrate.”

Cook a 12-16 ounce box of dried pasta in 4 quarts of water. Before adding the noodles to the pot, bring the water to a rolling boil and season it with 2 tablespoons of salt, preferably Mediterranean sea salt or kosher salt.

The same proportions apply to fresh pasta as well. The only notable difference is that, because fresh pasta has about twice as much moisture compared to dried pasta (respectively, 30% and 12.5% on average), it takes significantly less time to cook.

The salt will dissolve in the water, the noodles will absorb it as they rehydrate and cook, and it will season them on the inside, enhancing the overall taste of your pasta dish.

Cook the Noodles Al Dente

Cooks in the U.S. and Canada typically overcook their pasta. Most recipes call for a long cooking time that causes the noodles to come out soft and mushy. Occasionally, pasta is finished off in the oven, where it cooks in the sauce for even longer.

Pasta in Italy is, by North American standards, undercooked. Especially the pasta prepared in the capital city of Rome and its surrounding area. Romans call this style of pasta “al dente” and the general consensus among cooks is that it is the better way of cooking pasta.

“Al dente” is an Italian term that chefs and restaurateurs use to describe perfectly-cooked pasta. It translates literally as “to the tooth” and describes noodles that have been cooked for 1-3 minutes less than the recommended time in the cooking instructions on the pasta package.

Al dente pasta is tender and cooked through on the inside, but still firm to the bite and with a slight crunch on the outside. Since the noodles hold on to their shape better and have a rougher surface, pasta sauce clings better to them and they come out more appetizing.

Pasta cooked al dente has a lower glycemic index. This makes it slower for your stomach to digest. Instead of tiring you out and making you feel slouchy, the carbohydrates (starches and sugars) and protein (gluten) in the noodles become a gradual source of energy for your body.

Add Some Pasta Water to Your Sauce

Starch is water-soluble and breaks down easily in the presence of moisture and heat. When you cook pasta in boiling water, some of the starch granules on the surface of the noodles will dissolve into the water, making it cloudy and viscous.

Most cooks make the mistake of throwing away all of that cloudy, viscous, and generously salted pasta water. But you can pick up one thing that Italian chefs do, which will greatly enhance your pasta dish.

Cook your pasta sauce in a saucepan while you’re boiling the noodles in a pasta pot. Mid-cooking, pick up a soup ladle and transfer some pasta water to the sauce as it cooks.

The gelatinized starches in the pasta water will help to thicken your pasta sauce. It will also absorb some of the taste of salty pasta as it incorporates the aromas and flavors of the pasta water and cooks down with it.

This technique is so simple and works so well, I guarantee you that you’ll be blown away by the difference. It works just as well on tomato- as it does on cheese- and cream-based sauces.

Sauce Your Pasta the Right Way

“If you’re taking your pasta right out of the water and putting it directly on the plate, and then putting your sauce right on top of your pasta, then you’re doing it all wrong,” says chef and cookbook author Andrew Carmellini.

“Take the hot pasta right out of the pasta water and put it inside the pot with the hot sauce.” Carmellini recommends cooking the pasta noodles with the pasta sauce for about 1 minute. That way, the aromas and flavors of the noodles and the sauce will blend together.

Saucing pasta
Saucing your pasta correctly

Plate the pasta after you’ve done this—and grate hard Italian cheese like Pecorino-Romano or Parmigiano-Reggiano on top. The cheese will add a flaky texture, briny aroma, and salty flavor that will enrich the overall look and feel of your pasta dish.

What Not to Do (The 5 Don’ts of Cooking Pasta)

When it comes to the science of cooking the perfect pasta, knowing what not to do is just as important as knowing what to do. Here are the five most common mistakes that home cooks make when cooking pasta—and how to avoid them.

Don’t add the noodles to a pot of water you haven’t brought to a boil. Getting the timing right will be tricky and they’ll most probably come out wet and soggy.

Don’t wash pasta before cooking it. You’ll end up washing away some of the starches on the surface of the noodles instead of letting them dissolve into the salty pasta water.

Don’t add olive oil to your pasta water. Oil won’t keep the noodles from sticking together. Since oil and water molecules don’t mix, most of the olive oil will end up floating, rather uselessly, on the surface of your pasta water.

Don’t cook the pasta for too long. Start tasting the noodles 3 minutes before the recommended time in the cooking instructions on the package. As soon as they’re al dente, strain them, mix them with the sauce, and serve.

Don’t rinse pasta after cooking it. The noodles are coated with salty and starchy pasta water that adds to the overall taste of your pasta dish. Simply strain the noodles without rinsing them.

What to Read Next

If you’re serious about homemade pasta, you’re going to like my list of the 10 must-have tools for making pasta.

Check out our editor’s pasta carbonara recipe. It’s hearty, filling, and made the traditional Roman way (without the use of heavy cream). If you’re craving savory pasta with tomato sauce, check out my tagliatelle, tomato, and anchovy pasta recipe.

Last but not least, check out one of my most read posts of all time, where I write about the best Italian pasta brands that you can find in the grocery store.

Know your author

Written by

Jim is the former editor of Home Cook World. He is a career food writer who's been cooking and baking at home ever since he could see over the counter and put a chair by the stove.