Latest news with #PhysicsofFluids
Fast Company
06-05-2025
- Science
- Fast Company
Scientists just designed the perfect cacio e pepe recipe
Chances are, if you're not an Italian grandma or a skilled home chef from Rome, you've probably messed up while trying to make cacio e pepe. At least, that's the thesis underpinning the scientific study ' Phase behavior of Cacio e Pepe sauce,' published on April 29 in the journal Physics of Fluids. The study—conducted by a group of scientists from the University of Barcelona, the Max Planck Institute for the Physics of Complex Systems in Germany, the University of Padova in Italy, and the Institute of Science and Technology Austria—is pretty much what its title suggests: a full-on scientific investigation into the most 'optimized recipe' for the creamy, peppery pasta dish. 'We're Italians living abroad, and we often get together for dinner to enjoy traditional recipes from home,' says Ivan Di Terlizzi, the study's lead author and a postdoctoral researcher at the Max Planck Institute. 'Among the dishes we've cooked, cacio e pepe came up several times, and every time, we were struck by how hard it is to get the sauce right. That's when we realized it might actually be an interesting physical system to study. And of course, there was also the very practical motivation of avoiding the heartbreak of wasting good pecorino!' A very brief history of pasta-based physics experiments This isn't the first time that pasta has been used as inspiration for physicists. Probably the most famous example of 'pasta as experiment,' Di Terlizzi says, is the observation that spaghetti almost never breaks cleanly in half, tending to snap into three or more fragments instead. This fact originally puzzled renowned physicist Richard Feynman (who died in 1988) and wasn't fully explained until 2005, when a team of French physicists showed that it's caused by cascading cracks traveling along the pasta. Another example, Di Terlizzi adds, is the physics of ring-shaped polymers, which are 'notoriously hard to understand.' A study in 2014 used a type of circular pasta, which the researchers called 'anelloni,' to explain why these looped polymers behave so strangely in experiments. With cacio e pepe, the physics question of interest has to do with the sauce's unusual behavior under heat. 'The main goal of our work wasn't just culinary; it was to explore the physics of this system,' Di Terlizzi says. 'The sauce's behavior under heat shares features with many physical and biological phenomena, like phase transitions or the formation of membrane-less organelles inside cells. The recipe is, in a sense, the practical byproduct of everything we learned.' The most optimal cacio e pepe recipe, according to scientists Cacio e pepe traditionally only includes three ingredients: pasta, pecorino Romano cheese, and black pepper. While it seems like a simple enough concoction, the sauce's creamy smoothness (the backbone of the dish) can be quite finicky to achieve. When the temperature gets too high or the mixing of cheese and pasta water isn't done carefully, the cheese proteins will denature—essentially 'unfolding' and losing their normal 3D structure. In the unfolded state, the proteins then stick together and the emulsion breaks. 'Instead of a creamy consistency, you get a gooey mess, which we call salsa impazzita. . . that is, crazy sauce,' Di Terlizzi says. The physics-based solution to 'crazy sauce'? It's all about starch. It turns out that, by perfecting the ratio of starch in the pasta water to cheese mass, the cacio e pepe sauce becomes far more resistant to heat, which stabilizes the emulsion and prevents clumping. 'Without starch, the so-called 'mozzarella phase' kicks in at around 65°C, where the proteins start forming large aggregates,' Di Terlizzi says. 'But if the starch concentration is above 1% relative to the cheese mass, the clumps stay small, and temperature becomes much less critical, making it much easier to get a good result.' This is similar to using polymers to stabilize emulsions in soft matter physics, he adds. 'Phase behavior of cacio e pepe sauce' contains ultra-detailed steps to a foolproof cacio e pepe, but here are the instructions in condensed terms: Step 1: For a pasta dish for 'two hungry people,' start with 300 grams of the preferred tonnarelli pasta—or opt for spaghetti or rigatoni, if you must. From there, you'll need 200 grams of cheese. 'Traditionalists would insist on using only pecorino Romano DOP [protected designation of origin], but some argue that up to 30% parmigiano Reggiano DOP is acceptable; though this remains a point of debate,' the recipe notes. Proceed based on your own personally held cheese preferences. Step 2: To prepare the sauce, dissolve 5 grams of starch—like potato or corn starch—in 50 grams of water. Heat this mixture gently until it thickens and turns from cloudy to nearly clear. This is your starch gel. Step 3: Add 100 grams of water to the starch gel. Instead of manually grating the cheese into the resulting liquid, blend the two together to achieve a homogeneous sauce. Finish the sauce by adding black pepper to taste (for best results, toast the pepper in a pan before adding). Step 4: To prepare the pasta, cook in slightly salted water until it is al dente. Save some of the pasta cooking water before draining. Once the pasta has been drained, let it cool down for up to a minute to prevent the excessive heat from destabilizing the sauce. Finally, mix the pasta with the sauce, ensuring even coating, and adjust the consistency by gradually adding reserved pasta water as needed.
RTÉ News
30-04-2025
- Science
- RTÉ News
Science-backed method for the perfect cacio e pepe recipe
Cacio e pepe, a beloved pasta dish from Italy's Lazio region, is made with just three ingredients: pasta, ground black pepper, and, most importantly, authentic Pecorino Romano cheese. However, the simplicity of its ingredients can be misleading. Many assume it's easy to make, only to end up with a clumpy mess instead of the silky, creamy sauce they hoped for. Intrigued by the challenge, researchers from the University of Barcelona, the Max Planck Institute for the Physics of Complex Systems, the University of Padova, and the Institute of Science and Technology Austria took it upon themselves to investigate the physics behind mixing cheese with water. Now, they believe they've cracked the code to perfecting this classic dish. Explaining the motives behind this study, which was published in Physics of Fluids, author Ivan Di Terlizzi said: "We are Italians living abroad. We often have dinner together and enjoy traditional cooking. "Among the dishes we have cooked was cacio e pepe, and we thought this might be an interesting physical system to study and describe. And of course, there was the practical aim to avoid wasting good Pecorino." After conducting tests that honed in on the quantities of these ingredients, the researchers determined that a 2 per cent to 3 per cent starch-to-cheese ratio created the smoothest and most consistent sauce. To achieve this level of precision, the team recommend using powdered starch – such as potato or corn starch – instead of depending on the unpredictable starch content of pasta water. "Because starch is such an important ingredient, and the amount of starch can sharply determine where you end up, what we suggest is to use an amount of starch which is precisely measured," advised Di Terlizzi. "And this can only be done if you have the right amount of powdered starch in proportion to the amount of cheese that you're using." Once the starch is added to the water, the authors' instructions say to blend it with the cheese for a uniform consistency, before adding the sauce back into the pan and slowly heating it up to serving temperature. If you've ever attempted to make cacio e pepe, you might have noticed that excessive heat can cause pieces of grated cheese to clump together, resulting in that dreaded, lumpy texture. To avoid this, the researchers experimented with different temperatures and recommend letting the water cool slightly before adding the cheese, and then to gradually warm up the sauce to reach the desired consistency. Then mix in the pepper and pasta, and eat. And after perfecting the cacio e pepe recipe, the team are keen to conduct further experiments on other popular Italian dishes. "There's a recipe called pasta alla gricia, which is cacio e pepe plus guanciale, cured pork cheek," said author Daniel Maria Busiello. "This recipe seems to be easier to perform, and we don't know exactly why. This is one idea we might explore in the future."
Forbes
29-04-2025
- Entertainment
- Forbes
What Physicists Perfecting Cacio E Pepe Misses About Why We Cook
Science may have perfected the sauce, but the real recipe was always about something more: memory, ... More ritual, and making meaning through imperfection. When scientists recently unveiled a physics-based method to perfect cacio e pepe—eliminating the dish's infamous clumping through a mathematical model—it felt like a breakthrough. Or maybe a provocation. Published by the American Institute of Physics, in the journal Physics of Fluids, the study framed the dish as a technical problem: a sauce destabilized by heat and starch, solvable through precise emulsification timing and temperature control. It's an impressive feat of culinary chemistry. They cracked the code of a process and a dish that so many of us couldn't get right. But for many of us, it also misses the point. Because if you've ever stood at a pan over a hot stove, trying to time each ingredient just right—your heart pounding, the cheese clumping, the sauce refusing to come together—you know cacio e pepe, like so many weeknight dishes, is about emotion and intuition as much as execution. It's a dish that can humble even the most seasoned cooks. It's got character and soul. And that's part of the appeal. This isn't the first time someone has tried to conquer cacio e pepe. YouTuber Alex of French Guy Cooking spent weeks attempting to nail the dish's elusive sauce in a now-beloved video series. His journey wasn't just about pasta—it was about patience, failure, and the quiet satisfaction of learning something the hard way. In one episode, he admits it wasn't the ingredients holding him back—it was his technique. His own hands. That moment resonated because it was honest. Mastery, for most of us, isn't sterile. It's messy. It's deeply personal. And sometimes, what we remember most isn't the finished dish—it's the muscle memory we build while trying. It's the feeling of getting closer, even if we never quite stick the landing. In a culture craving comfort and connection, our obsession with 'perfect' food may be missing what ... More people are truly hungry for: emotional resonance. This pursuit of 'perfect' cooking is unfolding in a moment when people are actually craving the opposite. According to Barilla's 2025 Trend Watch, there's a notable return to classic pasta dishes like carbonara, amatriciana, and cacio e pepe—beloved not for their technical challenges but for their comfort, familiarity, and emotional resonance. These are dishes being refreshed, not reinvented. There's a cultural hunger right now for food that feels safe, known, and human. That often means embracing imperfection—not solving for it. At the same time, cooking has never been more emotionally charged. A 2018 study in the journal Appetite found that 'cooking anxiety'—the stress and fear of messing up in the kitchen—is common, especially among less confident home cooks. And in an era shaped by food influencers, TikTok recipe hacks, and hyper-edited cooking shows, the pressure to perform has only grown. So when science steps in to 'perfect' a dish like cacio e pepe, it can feel like an effort that risks flattening the very thing that gives it life: the trial and error, the human error, the emotional stakes. When we crave a dish like cacio e pepe, we're not just chasing a flavor. We're chasing memory, ... More warmth, and the forgiving embrace of imperfection. The truth is, many of us aren't looking for flawless food. We're looking for food that feels like home—even if that home is slightly chaotic. We want recipes and meals that forgive us when we get distracted. We want to feel something. Cacio e pepe, deceptively simple, holds a particular kind of weight: it's the kind of dish you might have tried to recreate from memory. Or from a grandmother's instructions that included more feeling than measurement. Maybe you've made it late at night after a long day, too tired to care about clumping, or felt tempted to make the Americanized version (with cream), just wanting something warm and salty and good enough. That's not something you can model in a lab. You have to live it. In American kitchens—shaped by migration, substitution, and shortcuts passed down like heirlooms—dishes like cacio e pepe take on a different kind of meaning. They're less about nailing tradition and more about negotiating memory. For many of us, the version we grew up with wasn't 'authentic' in the Roman sense, but it was familiar, adapted, and emotionally exact. The butter might have been salted. The pasta water ratio was guesswork. It still fed us. It still stuck. And as philosopher Andrea Baldini writes in a 2020 essay on 'imperfectionism in cooking' published in there's value in that mess. His term describes recipes that emerge not from a flawless plan but from spontaneous adjustments, improvisation, and even mistakes. These dishes aren't lesser versions of their originals—they're expressions of humanity, creativity, and adaptability. They remind us that imperfection isn't a flaw. It's a feature. When we crave a dish like cacio e pepe, we're not just chasing a flavor. We're chasing memory, ... More warmth, and the forgiving embrace of imperfection. In the end, the scientists did solve a real problem. But in doing so, they surfaced a deeper issue: our discomfort with food that doesn't behave nicely. Or maybe our discomfort with ourselves when we don't get it right. But what if getting it right was never the point? Maybe we should keep returning to cacio e pepe, not because it's perfect but because it asks us to try. It offers us a little challenge, a little grace, and a chance to see what happens when we put our hands—and hearts—into something anyway. And maybe that's the kind of perfection we need more of.
New York Times
23-04-2025
- Science
- New York Times
The Physics of the Perfect Pour Over
More than a billion cups of coffee are consumed daily: French-press, espresso, cold brew, whatever it takes. Arnold Mathijssen, a physicist at the University of Pennsylvania, is partial to pour-over coffee, which involves manually pouring hot water over ground beans and filtering it into a pot or mug below. Surely, he figured, applying the principles of fluid dynamics to the process could make it even better. With two students of similar mind, Dr. Mathijssen began studying how to optimize the pour in a pour over. Their science-backed advice: Pour high, slow and with a steady stream of water. This ensures the greatest extraction from minimal grounds, enhancing the coffee's flavor without added beans or cost. The findings, published this month in the journal Physics of Fluids, highlight how processes that unfold in the kitchen — from making foie gras to whipping up a plate of cacio e pepe — can inspire new scientific directions. In turn, science can enhance the art of cuisine. 'Kitchen science starts off with a relatively low entry barrier,' Dr. Mathijssen said. 'But it's more than just cute. Sometimes fundamental things can come out of it.' Dr. Mathijssen primarily studies the physics of biological flows, such as the way bacteria swim upstream in blood vessels. But when he lost access to his lab during the Covid-19 shutdown, he started playing with his food — literally. He shook up bottles of whiskey, tested the stickiness of pasta and slid coins down slopes made of whipped cream and honey. The interest culminated in a 77-page review, structured like a menu, of the physics involved in making a meal. 'It got totally out of hand,' Dr. Mathijssen said. 'You just realize science is everywhere.' Dr. Mathijssen has since returned to the lab, but the passion for kitchen physics has stuck. The coffee study was partly inspired by a scientist in his group who kept detailed notes about pour-over brews prepared in the lab each day. The notes included information about where the beans had come from, the extraction time and the brew's flavor profile. Ernest Park, a graduate student in the lab, designed a formal experiment. Using silica gel beads in a glass cone, the scientists simulated the action of water being poured over coffee grounds from different heights, recording the dynamics of the system with a high-speed camera. Then they brewed pots of real coffee, pouring from a gooseneck kettle, at varying heights. The resulting liquid was allowed to evaporate in an oven until all that remained were the coffee particles extracted from the grounds. They found that more coffee particles remained when they had poured slowly, which increased the time the water was in contact with the grounds. Holding the kettle higher helped with the mixing, preventing the water from draining along the sides, between the grounds and the filter. This type of flow caused what the researchers described as an avalanche effect. The water eroded the center of the pile of coffee grounds, thus suspending some of the grains, which settled and built up on the sides. Eventually, the sides collapsed inward and the process started again. This increased the flavor extracted from the coffee grounds, but only as long as the water was allowed to flow continuously. 'Your jet of water coming out should look like a smooth column all the way down,' said Margot Young, a graduate student — and former barista — involved in the study. 'If you see it starting to break up, or you can see droplets, then you have to pour from lower down.' The scientists conducted informal taste tests, although these did not make it into the final publication. 'Taste-wise, it's very subjective,' Mr. Park said. 'So we always suggest that you try it yourself.' Mr. Park noted that the study examined only water poured into the center of the coffee grounds, although future experiments could explore other techniques, like making swirls or spirals. Scientific phenomena observed in the kitchen typically have analogues outside its walls. The dynamics between a jet of hot water and a bed of coffee grains, for instance, are similar to the erosion of land that can occur around waterfalls and dams. A stirred pot of soup assumes the same shape as the liquid mirrors of some telescopes. Observations of soap bubbles by Agnes Pockels, a 19th-century German homemaker, gave rise to the field of surface science and laid the groundwork for nanotechnology. In 2022, Dr. Mathijssen helped assemble an array of studies, produced by scientists around the world, into a collection called Kitchen Flows. He is now helping compile a second collection, which so far consists of more than 30 studies, including insights into the behavior of an egg yolk, the sloshing of a bottle of beer and the most efficient way to boil pasta. Dr. Mathijssen also plans to continue exploring the many paths to perfect coffee, such as the physics behind the formation of the milk and espresso layers in a latte. 'I want to do some more work in this direction,' he said. 'And then maybe also something about cold brews.'
Yahoo
08-04-2025
- Science
- Yahoo
How to brew the best pour-over coffee, according to science
Brewing coffee is a part of many people's mundane, everyday routines. But you don't necessarily need to pay exorbitant prices for premium roasts if you want to improve what's in your cup. Sometimes, all that's required is a basic understanding of the pour-over method's interplay between molecular chemistry, physics, and fluid dynamics. Don't worry—it's not as complex as it sounds. At least, not according to a study published by University of Pennsylvania researchers on April 8 in Physics of Fluids. To better understand the microscopic interactions and internal dynamics that occur during pour-over brewing, the team first swapped opaque coffee grounds for silica gel particles inside a glass cone. They then used a laser sheet and a high-speed camera to capture in detail how fine-grained materials like ground coffee respond to water poured from a standard gooseneck kettle at various heights and strengths. It soon became clear that the best pour-over coffee requires generating an avalanche effect in the grains—an outcome best achieved by a combination of height and intensity. 'What we recommend is making the pour height as high as possible, while still maintaining a laminar flow, where the jet doesn't break up when it impacts the coffee grinds,' study co-author Ernest Park explained in a statement. Pouring a steady stream at a greater height allows grounds to displace and recirculate as the water pushes deeper into the coffee bed. The study authors also noted that although this method often produces a layer of floating grains on top of the water, the effect doesn't 'significantly impact' the mixing. But what can negatively affect brewing is when water hits the grounds is too thin or has a weak jet. 'If you have a thin jet, then it tends to break up into droplets. That's what you want to avoid in these pour-overs, because that means the jet cannot mix the coffee grounds effectively,' added co-author Margot Young. 'Together, these results indicate that the extraction of the coffee can be tuned by prolonging the mixing time with slower but more effective pours using avalanche dynamics,' the team summarizes in their study. Adopting this strategy won't only improve your cup of coffee—it's the more environmentally responsible thing to do. Humans consume tens of billions of pounds of coffee every year, but the overall industry simply isn't sustainable at its current rate. Climate change already endangers huge portions of global coffee cultivation, particularly in regions like Ethiopia and Brazil. Science-backed brewing like Park and Young's pour-over method not only makes a more flavorful and enjoyable coffee, but does so using fewer beans. 'Instead of increasing the amount of beans, the sensory profile and the strength of the beverage can be adjusted by varying the flow rate and the pour height,' they write. 'In this way, the extraction efficiency could be better controlled to help alleviate the demand on coffee beans worldwide.'
