Impressing guests with an expertly prepared pasta dish is a surefire way to elevate any dinner party.
Born in Rome and passionate about food, I would contend that cacio e pepe—a traditional Roman pasta dish—might be a daring choice for beginners in the kitchen. It’s simple yet can be quite tricky.
As the name implies, the recipe requires just three ingredients: pasta, cheese (cacio), and black pepper (pepe). That’s literally it.
“There’s no room for mistakes when you’re only using pasta, Pecorino Romano cheese, and black pepper,” says Michele Casadei Massari, who runs Lucciola Italian Restaurant in Manhattan.
“The key challenge is to create a stable emulsion. If the cheese gets too hot or if the starch-to-water ratio isn’t right, the sauce will break apart,” Massari explains.
When that happens, the cheese turns into a gloopy mass that clings to everything except the pasta—quite disappointing.
So how can you avoid a dinnertime disaster? It seems the options are either to practice endlessly (and learn from mistakes) or to rely on scientific principles for guidance.
A group of Italian physicists recently collaborated to decode a foolproof cacio e pepe recipe. They studied the behavior of cheese, starch, and water at varying temperatures to discover how to achieve consistent results.
Published on April 29 in the journal Physics of Fluids, their study reveals a clever trick: incorporating a specific amount of cornstarch based on the cheese quantity helps prevent clumping.
Initially, when I heard about this method, my inner traditionalist was skeptical.
I’ve often encountered “hacks” for perfecting classic dishes—like adding cream to carbonara (a huge no-no). So, out of fairness, I thought I’d test the recipe myself and speak with the researchers behind it.
During a conversation in Italian, three study authors shared their frustration with poorly executed cacio e pepe dishes, leading them to seek a scientific approach to the problem.
“While at the Max Planck Institute in Dresden, we often cooked Italian recipes—not just for ourselves, but for others too,” recounted study coauthor Daniel Maria Busiello from the University of Padova.
But attempting to make large servings of cacio e pepe proved challenging. “Controlling the temperature of the sauce and pasta often resulted in clumps,” Busiello remembered.
“I distinctly recall when the dish came out inedible. That sparked an epiphany,” noted fellow researcher Ivan Di Terlizzi, a statistical physicist.
Di Terlizzi shared his hypothesis about the connection between cacio e pepe sauce behavior and protein aggregation in cells with Giacomo Bartolucci, a biophysicist now in Barcelona.
Their goal was to determine whether the cheese and water could be scientifically classified as a “system that undergoes phase separation at high temperatures.”
“We had theoretical insights and a practical problem to tackle,” Busiello added.
Innovating traditional Italian recipes with a scientific slant carries its own risks. All eight researchers behind this study are Italian—by design, naturally.
“If we have to upset some people, let’s at least make sure it’s eight Italians,” Di Terlizzi said.
The team conducted controlled experiments to better understand the behavior of cacio e pepe sauce when heated.
“We prepared small batches with precise amounts of cheese, starch, and water, gradually heating them using sous vide techniques to carefully monitor the temperature,” Di Terlizzi explained.
Samples of the sauce were collected at each phase, allowing them to photograph and assess how clumping occurred, revealing the impact of temperature and ingredients on sauce smoothness.
Their research indicated that starch concentration was crucial for the sauce’s stability. If the starch ratio falls below 1% of the cheese weight, clumping occurs, ruining the dish. A 2% to 3% ratio is optimal.
The study outlined a recipe intended for two people, which included 5 grams of cornstarch or potato starch dissolved in water, gently heated to form a gel, cooled with additional water, and then blended with 200 grams of pecorino cheese.
They also found that sodium citrate—often used for smooth mac and cheese—works well in their recipe, although it adds a slight aftertaste reminiscent of processed cheese.
The pecorino cream crafted using science demonstrates better temperature resilience compared to the traditional cheese-water mixture, even allowing for reheating.
Temperature plays a significant role in how the cheese proteins react when heated.
“The sauce is stable when created at lower temperatures, allowing the starch to bond with the proteins. If exposed to high heat after that bonding, protein interactions may falter,” Di Terlizzi explained.
The scientifically improved recipe promises consistent results for large pasta servings, giving the cook greater freedom in handling hot noodles, which cool more slowly than smaller amounts.
Just a note—don’t discard all the pasta cooking water! You’ll still need some for mixing everything together (or “mantecatura,” as the Italians say). Just ensure it cools a bit first.
When I tried the recipe, I found the steps clear and the process swift, though it involved a couple of extra steps compared to my usual methods (like making the starch gel on the stove).
The experience was quite peculiar, working with a pecorino cream that felt so smooth—almost like a sauce from a jar. The pepper, however, remained intact; just add as much as you prefer and toast it for the best aroma.
My husband and I relished the meal. It tasted delightful, and dealing with a cream that required less babysitting and a less time-sensitive mantecatura was a huge advantage. Plus, the idea of hosting a cacio e pepe party for friends sounds like a blast!
I did have one small reservation; knowing there was starch, I noticed a change in the mouthfeel of the dish, though my husband didn’t find it at all off-putting.
As a dedicated home cook from Rome, I’m committed to perfecting the classic cacio e pepe, but this scientifically refined version exceeded my expectations. It’s a great introduction for anyone who’s been hesitant to try making it themselves.
The classic method of emulsifying cheese with pasta water poses challenges, mostly because it’s nearly impossible to predict the starch content in the cooking water. Success often feels like a gamble, but there are ways to minimize mishaps.
One tip from Massari is to use less water for boiling the pasta.
“For cacio e pepe, aim for about 6 to 8 cups of water for 7 ounces of pasta, which is a ratio of 1 part pasta to 6–7 parts water by weight—less than the usual method,” he suggests.
As a traditional guideline, about 1 quart of water is usually recommended for every 3½ ounces of pasta, with 2 teaspoons of salt.
The researchers in their experiments employed a 10-to-1 water-to-pasta ratio, and found that cutting back the water by two-thirds effectively concentrated the natural pasta starch sufficiently.
Massari also advises mixing the cheese and pasta water below 60 degrees Celsius (140 degrees Fahrenheit), which aligns with the study’s temperature findings.
“First, I create a cold cheese cream by mixing finely grated Pecorino with a bit of the starchy pasta water until smooth. Then, I toss the pasta off heat with the cream and freshly cracked black pepper, adding water to adjust the consistency,” he elaborated. “The aim is a silky sauce that adheres nicely to the pasta, not a heavy coating.”
“Using properly managed pasta naturally yields enough starch for a creamy, stable sauce without compromising nutritional value,” he added.
Another helpful tip for easing the traditional method involves “pasta regeneration.” This means partially cooking the pasta for around 70% of the time, shocking it in ice water to halt cooking, and finishing it right before serving.
“This technique preserves al dente texture while enhancing the release of surface starch vital for stabilizing emulsions,” Massari noted.
The researchers’ optimized recipe has gained quite the following—both as a meme online and in conversation.
“Some users were critical of our proposed recipe, despite its previous use in renowned restaurants,” Di Terlizzi remarked. “Yet, the general response has leaned towards excitement, particularly within the scientific community.”
“We can’t claim to have invented the ultimate method,” Di Terlizzi said, but this approach can help prevent wasting good, hard-to-find pecorino cheese.
For the researchers, this project is particularly personal: “Here we are in Germany, sourcing our ingredients from Italy. It’s not something we can just pick up at the local store,” Di Terlizzi explained. “So, when a dish flops, it really affects us.”
Celebrating the study’s publication, they prepared a large pasta dinner, dishing out at least 4 pounds for their guests.
“We were really anxious because the diners were all aware of our experiment—but it turned out great,” Busiello shared.
Bartolucci added, “That was our trial by fire.”
This summary reflects the recipe shared in the study. You can find Pecorino Romano DOP—certified by the Italian government and the EU—and tonnarelli pasta at Italian grocery stores and specialty online shops.
Makes 2 servings.
Ingredients
• Salt
• 5 grams (2 teaspoons) cracked black peppercorns, plus extra for serving
• 5 grams (2 teaspoons) cornstarch or potato starch
• 200 grams (1 ½ cups, firmly packed) pregrated Pecorino Romano DOP (like Fulvi or Locatelli), with more for serving
• 300 grams (10.6 ounces) pasta, preferably tonnarelli (spaghetti or rigatoni also work)
Instructions
1. Boil a large pot of lightly salted water.
2. While the water heats, toast the peppercorns in a dry pan over medium-low heat until fragrant, then remove from heat.
3. Prepare the starch gel by whisking cornstarch into 50 grams (3 tablespoons plus 1 teaspoon) of cold water in a small saucepan. Gently heat until it thickens and becomes clear, then mix in 100 grams (6 ¾ tablespoons) of water to cool it down.
4. Combine the starchy water, grated cheese, and peppercorns in a food processor and blend until it forms a smooth cream.
5. Cook the pasta according to the package instructions until al dente, reserving 237 milliliters (1 cup) of the cooking liquid before draining. Let the pasta cool for about a minute.
6. Mix the pasta with the sauce, ensuring it’s evenly coated. Adjust the consistency with pasta water as needed, keeping the sauce a bit runny since it thickens as it cools. Gentle reheating (up to 80 or 90 degrees Celsius) is possible if needed.
7. Top with extra grated cheese and pepper, and serve right away.
“For optimal results, I suggest using high-quality spaghettoni made from durum wheat semolina, ideally bronze-extruded and slow-dried at lower temps,” Massari advised. “I favor Matt, a heritage durum wheat mainly from Puglia and Sicily.”
You can find Matt spaghettoni, Sarawak black peppercorns, and Pecorino Romano DOP at specialty online shops.
Makes 2 servings.
Ingredients
• Coarse Sicilian sea salt
• 5 grams (1 teaspoon) freshly cracked Sarawak black peppercorns, with extra for serving
• 100 grams (1 cup, firmly packed) pregrated Pecorino Romano DOP (like Fulvi or Locatelli), plus more for serving
• 200 grams (7 ounces) spaghettoni, ideally from Matt durum wheat
Directions
1. In a large pot, bring 6 to 8 cups of lightly salted water to a boil. Toast the black pepper in a dry pan over medium-low heat until fragrant, and take it off the heat.
2. Cook the spaghettoni according to package directions until slightly al dente, reserving 237 grams (1 cup) of cooking liquid.
3. While the pasta cooks, prepare a cold emulsion by mixing grated Pecorino with a bit of warm pasta water (ideally below 60 degrees Celsius) in a medium bowl until you get a creamy base.
4. Once slightly al dente, drain the pasta and transfer it to the pan with the pepper.
5. Mix the pasta with the Pecorino cream, gradually add pasta water for a glossy sauce that perfectly coats each strand. Add more pepper and cheese before serving. Serve right away.
