# Cacio e Pepe (Creamy Roman Pasta)

Cacio e pepe means cheese and pepper, and that is nearly the whole recipe: spaghetti, Pecorino Romano, black pepper and starchy pasta water. Done right, it is creamy, sharp and peppery, with no cream at all.

It is also famous for clumping. The fix is simple: make a cheese paste with warm water first, and add it off the heat.

- Total time: 20 min (prep 5 min, cook 15 min)
- Serves: 4
- Per serving (estimated): 560 kcal, 23 g protein
- Cuisine: Italian. Category: Main course. Diet: vegetarian.

## Ingredients

- 400 g spaghetti or tonnarelli
- 100 g Pecorino Romano, finely grated (about 1 1/4 cups)
- 2 tsp black peppercorns, freshly cracked coarse
- 2 tbsp butter (optional, for insurance)
- Salt, a small pinch for the pasta water

## Method

1. Bring 3 liters (3 quarts) of water to a boil, which is less water than usual so the pasta water stays starchy. Add only a small pinch of salt, since the cheese is salty.
2. Toast the pepper in a dry 12-inch skillet over medium heat for 1 minute, until it smells fragrant and a little smoky. Turn off the heat.
3. Cook the spaghetti 2 minutes short of the package time, so it is quite firm in the center. Scoop out 2 cups of pasta water before draining.
4. Mix the Pecorino in a bowl with 1/2 cup of the pasta water, stirring into a thick, smooth paste. Let it cool for 1 minute if the water was very hot.
5. Move the pasta to the skillet with the pepper and add 1/2 cup of pasta water. Cook over medium heat, tossing, for 1 to 2 minutes until the water is mostly absorbed and the pasta is al dente.
6. Take the pan off the heat. Add the cheese paste and the butter, tossing hard and fast with tongs for about 1 minute.
7. Add pasta water a spoonful at a time until the sauce turns creamy, glossy and loose enough to flow. Serve at once with more pepper and cheese.

## Why it works

- Cooking pasta in less water makes the water extra starchy, which is the key to a smooth sauce.
- Toasting the pepper wakes up its oils, so the flavor is rounder and more aromatic.
- Making a paste of cheese and water first prevents the cheese from meeting direct heat, which makes it clump.
- Taking the pan off the burner keeps the Pecorino below the temperature where its proteins tighten and stringy lumps form.
- Finishing the noodles in a little water lets them absorb flavor and release more starch into the sauce.

## The science

- **Why cheese clumps.** When Pecorino gets too hot or too dry, its proteins bond tightly together and squeeze out fat, forming rubbery clumps. Dispersing the cheese in warm starchy water first spreads those proteins out, so starch keeps them apart and the sauce stays smooth.
- **Starch as a stabilizer.** Starch granules released from pasta swell in hot water and thicken it. In cacio e pepe they coat the tiny fat droplets from the cheese and keep them suspended, forming an emulsion that tastes creamy even without cream.

## Tips

- Grate the Pecorino on the finest holes so it melts instantly.
- Crack the pepper coarsely with a pan or mortar rather than using fine pre-ground pepper.
- Serve on warm plates, because the sauce tightens as it cools.

## Mistakes to avoid

- Adding cheese directly to a hot pan, which makes clumps, so use the paste and pull the pan off the heat.
- Using too much pasta water at once, which makes the sauce watery, so add it a spoonful at a time.
- Over-salting the pasta water, which makes the dish too salty because Pecorino is already salty.

## Variations and swaps

- Use half Pecorino Romano and half Parmesan for a milder sauce.
- Add 1 tsp of olive oil and a squeeze of lemon at the end for brightness.
- Make it with rigatoni or bucatini instead of spaghetti.
- Swap Pecorino Romano for Parmigiano-Reggiano for a sweeter, nuttier version.
- Swap butter for extra-virgin olive oil to keep it closer to the traditional method.
- Swap spaghetti for tonnarelli, a thicker square-cut pasta, which holds the sauce well.

## Storage

Cacio e pepe is best eaten fresh because the sauce tightens and separates. Leftovers keep in the fridge for 2 days, and should be reheated in a skillet with a splash of water to 165°F (74°C).

## FAQ

**Why does my cacio e pepe clump?**

Clumps happen when the cheese hits heat that is too high or water that is too little. Mix the cheese with warm pasta water into a paste, and add it off the heat while tossing quickly.

**What cheese is used in cacio e pepe?**

Traditional cacio e pepe uses Pecorino Romano, a salty sheep's milk cheese. Some cooks blend in Parmigiano-Reggiano for a milder, sweeter flavor.

**Can I make cacio e pepe without butter?**

Yes, traditional recipes use no butter. The butter in this recipe is optional insurance that makes the sauce more forgiving for beginners.

**Is cacio e pepe vegetarian?**

It has no meat, so it is vegetarian by most definitions. Traditional Pecorino Romano is made with animal rennet, so strict vegetarians should look for a cheese made with vegetarian rennet.

**How do I fix a broken cacio e pepe sauce?**

Add a splash of hot pasta water and toss over very low heat, or whisk in a small knob of cold butter. This often brings the sauce back together.

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Source: https://cookingscientist.com/recipes/cacio-e-pepe (Cooking Scientist). Learn the science of cooking in the Cooking Scientist app for iPhone and iPad: https://apps.apple.com/app/id6830326846