The Food Lab: How to Make the Best Carne Asada

The Food Lab

Unraveling the mysteries of home cooking through science.

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Juicy, crisp, and smoky grilled carne asada. [Photographs: J. Kenji López-Alt]

Get the Recipe

To say "I'm going to develop a recipe for carne asada" is akin to saying "Bartender, get me a beer, please." The immediate follow-up is likely to be "I'm afraid you're going to have to be a bit more specific than that."

Carne asada literally translates to "grilled beef," and, at its simplest, it can be no more than a steak, seasoned with salt and pepper, cooked over a hot fire. Yet colloquially, when we hear the term "carne asada," we immediately think of the marinated meats you're going to chop up and stuff into your tacos, burritos, or cemitas. But what exactly is in that marinade? Depending on whom you ask, you'll get any number of different answers. Lime juice, garlic, and herbs are often used. Some recipes call for dried or fresh chilies. Still others go for a liquid fajita-style marinade with soy or Worcestershire sauce.

When I was a kid, my favorite Mexican restaurant was the Cal-Mex chain El Torito. We'd go to one of the New Jersey branches with the whole family. I'd eat the warm chips and watery salsa while coloring within the faux Mexican–themed outlines on the paper tablecloth with the crayons they'd give us, waiting for my deep-fried, cornflake-crusted, cinnamon-dusted ice cream to arrive. My dad would play with the slush in his margarita, a drink that, incidentally, was popularized in the United States by that very chain.

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I'd had many versions of carne asada in my short life (my dad loved Mexican restaurants), but when it came to filling in the grilled beef–shaped lines etched in my head, El Torito held the largest crayon by far. Their version was a slab of skirt steak marinated in a pasilla chili–based sauce, grilled hard over coals until nearly burnt and crisp around the edges, and served slathered with a salsa that combined fresh citrus and more of that pasilla.

The East Coast branches of El Torito have since closed, but I was delighted to discover when I moved out west that the chain was still going strong. When I decided to work on this recipe, my first step was to go straight to the source. I hit up El Torito three times over the course of two days to get a really good grasp of what they're doing with their carne asada. The flavor was vaguely as I remembered it—sweet, savory, a little spicy, and deeply charred—but I certainly didn't remember the meat being so mealy or gray. If this was going to be my prototype, I was going to have to make some major improvements before moving into full production.

Regardless of the exact flavors I ended up using in my recipe, I'm sure we can all agree on a few things here. Great carne asada should taste, first, of the beef. It should be buttery, rich, and juicy, with a charred, smoky flavor from the grill or broiler. It should also be tender enough that you can eat it in a taco or burrito, but substantial enough to be served as a steak and eaten with a knife and fork. Finally, the marinade should have a good balance of flavors, with no single ingredient overwhelming any other.

I hit up the butcher's counter on my way home and bought them out of every potential cut of beef that might work in my recipe. It was time to get serio with mi carne.

The Meat Counter

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Flap meat.

Carne asada is typically made with skirt steak, but I wanted to test out a variety of inexpensive cuts to be sure. I bought a half dozen different cuts of beef and marinated them in a basic mixture of lime juice, garlic, cilantro, olive oil, and chilies before grilling them to medium rare over hot coals.

  • Hanger is big and beefy, with a nice coarse texture that takes well to marinades, but its large triangular cross-section is not ideal for taco or burrito fillings.
  • Flank steak is easy to cook and slice because of its wide, flat shape, but it's a little too lean for this application.
  • Tri-tip, though quite inexpensive and nicely marbled, is simply too large. With such a low surface area–to–volume ratio, you get barely any marinade flavor.
  • Short ribs was one of my favorite cuts for carne asada (as well as one of my favorites for cooking as a steak), with tons of beef flavor and melt-in-your-mouth fat. The only problem is that they require very thin slicing, which is okay for stuffing tortillas, but not great if you want to serve them to guests in a whole chunk.
  • Flap meat, my second choice, has a wide, coarse texture that's custom-made for picking up and clinging to marinades. It is relatively lean, but its juiciness and big flavor make up for that.
  • Skirt steak, as suspected, was the clear winner here, with the richest, most buttery flavor, a really nice surface area–to–volume ratio that maximizes the flavor of the marinade, plenty of thin edges to crisp up and char, and, when cooked properly, a melt-in-your-mouth texture.
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Skirt steak.

Skirt steak comes as a long, ribbony piece of meat, with a width of three inches or so and a length of at least a couple of feet. The real key to working with skirt (and, when you buy it from the butcher, the vast majority of the time you're getting inside skirt—the fattier and more desirable outside skirt gets sold almost exclusively to restaurants) is to leave a relatively large amount of fat on it—I trim off just the really tough-looking silver skin—and to cut it crosswise with the grain into five- to six-inch lengths. This will subsequently allow you to cut it against the grain easily when serving.

The Keys to Great Marinades

Aside from the obvious one of adding flavor, a good marinade has three goals: enhancing texture by allowing meat to retain juices better, improving surface browning, and tenderizing. For our carne asada, we want all three of these effects.

I explored many of the different classes of ingredients that one might find in a marinade when I was working on a recipe for fajitas, a similar but distinct Mexican dish. In that article, I named four essential marinade ingredients that will guarantee maximum results in all of these categories.

Marinade Ingredients and Their Effects

Ingredient Effect Example
Flavoring Agents Adding flavor. Fresh aromatics, like onions or garlic, herbs, dried spices, sauces, and flavorful oils.
Acid Tenderization of tougher connective tissue. Vinegars, citrus juices, and wine.
Oil Enhancing surface browning and spreading oil-soluble flavors more evenly across the meat. Olive oil, canola oil, etc.
Salt Breaking down muscle protein to improve juice retention and to flavor. Solid salt and salty sauces like soy or fish sauce.
Protease Enzymatically breaking down proteins to tenderize. Papaya or pineapple juice, meat tenderizer, and soy sauce.
Sugar Improving browning and balancing flavor. Brown or white sugar and syrups like maple syrup or honey.
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The fresh contenders.

For my marinade, I knew that I'd want a mix of many of these ingredients, but there was simply too huge a range to start out with. So I began by making some broad strokes, testing out some basic styles I've seen in books and around the internet. After a few tests, I eliminated those liquid ones that seemed too similar to fajita marinades to me. I then eliminated those that were too heavy on oil and fresh aromatics, like garlic and herbs. Those ingredients were welcome, but I wanted the backbone of my marinade to be much more robust, like the El Torito version I was used to. Dried chilies was where I would begin.

The Chilies

I've tested and written extensively about how to get the best flavor out of your chilies, and my near-universal recommendation is to ditch the chili powder in lieu of whole dried chilies, which pretty much always have vastly superior flavor.

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Chilies.

I've also recommended toasting whole chilies in the microwave to enhance their flavor, and it works well in this recipe, too. All it takes is about 15 seconds on a microwave-safe plate for dried chilies to become toasty and pliable.

I tried incorporating chilies into my marinade in various ways, including steaming them in chicken stock and puréeing them (as I do in a couple of chili recipes), simply toasting and grinding them, and blending the toasted chilies into my liquid ingredients in my countertop blender.

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Cleaning guajillo chilies.

In this case, the easiest method turned out to be the best. Simply tossing toasted guajillo or pasilla and ancho chilies (along with some chipotles) into the blender with the liquid ingredients and grinding them up produced a marinade that was smooth enough to eat as a salsa, but still had a few pleasant bits of intact chili skin that softened up as the marinade sat.

The Wet Ingredients

Next step was to nail down the wet ingredients. Citrus juice was an obvious one. I tried straight-up lime, but it proved too acidic for the sauce, overpowering the other ingredients. A mixture of lime and orange toned down the acidity and added a nice floral note to the aroma, which went really well with the smoky chipotle chilies. A little olive oil also loosened up the mixture and provided some fat to distribute those fat-soluble flavor compounds around the meat.

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Flavor enhancers.

To improve the flavor of the mixture, I tried mixing in various ingredients, like molasses and Worcestershire sauce, an ingredient that is pretty prevalent in the El Torito version. But no matter how little I used, the combination of Worcestershire and sugar was too reminiscent of barbecue sauce. I cut it out completely.

In its place, I knew I wanted another ingredient rich in glutamic acid, the chemical responsible for triggering our sense of savoriness. I turned to the usual suspects: soy sauce and fish sauce.

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Umami, please.

A small dash of both gave the sauce the depth it needed and helped boost the flavor of the skirt steak, while simultaneously improving its moisture level and tenderness. Fish sauce is hardly traditional in Mexican cooking, but this is carne asada—there are no rules about anything, other than what lands on the plate at the end of the recipe. Besides, in the quantity used here, the fish sauce completely melds into the background.

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Dried spices.

Rounding out the flavors in my marinade were garlic, a small bunch of fresh cilantro leaves, some toasted whole cumin and coriander seeds, and some dark brown sugar to balance out all the extra saltiness and acidity.

Marinating Time

What about how long the marinade takes to work? Does marinating for hours or even days on end help, detract, or make no difference? To test this, I placed pieces of skirt steak into vacuum-sealed bags of marinade, sealing off a new bag every few hours to test marination times ranging from zero to 36 hours. Much to my wife's chagrin, this meant waking up every few hours in the middle of the night to a loud alarm so that I could go put another piece of beef on to marinate. I'm not sure why she puts up with me, but I think the food may have something to do with it.

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Marinated for various times.

After marinating, I decided that the only way to ensure that all of my samples cooked identically would be to cook them via sous vide, in a temperature-controlled water bath. Every steak spent one hour at 120°F, then a few minutes on a smoking-hot grill to bring them all up to a nice medium rare before tasting.

A dozen steaks later, I had come to a shocking conclusion: Aside from those that had spent zero to one hour in the marinade, most of the steaks tasted nearly identical, and not particularly tasty. Indeed, on the day that I was finishing this particular test, Tara Duggan of the San Francisco Chronicle was at my home working on a profile to coincide with the release of my upcoming book. I had to assure her, in my most sincere tone, that this recipe was still a work in progress in need of plenty of tweaks.

It was pretty obvious what was lacking from the marinade: salt. While I'd been putting as much salt in the marinade as I would use for a sauce to serve the meat with—about 1 1/2% to 2% salt by weight—a marinade actually needs to be far saltier in order for it to really be able to penetrate at all.

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Marinade penetration.

Many people seem to be under the impression that meat is like a paper towel, or perhaps a ShamWow, capable of absorbing whatever it is we dip it in. We'd see a lot more sponges and diapers made of meat if that were the case.

Okay, perhaps not, but you get my point: Meat is already packed full of stuff, so it's not particularly good at absorbing more stuff. In order to get it to absorb more at all, you need to alter its structure, and that's where salt comes in. In significant enough proportions, salt can dissolve the muscle proteins responsible for keeping meat fibers tightly bound. Once they're loosened, that salt can work its way into the meat, taking along with it a few other flavors as well.

Raising the salt content to 3% (just a couple of extra teaspoons) can significantly improve the flavor of the meat, though, even with extra salt, there's only so far a marinade can penetrate. Those big aromatic molecules in a marinade are simply too large to get far beyond the surface.

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Once I'd increased the amount of salt, I found that by three hours or so, the meat had absorbed the majority of the flavors it was going to pick up. The difference between meat marinated for one hour and meat marinated for three hours was far greater than the difference between a three-hour-marinated batch and a 12-hour-marinated batch. Eventually, though, the acid in the marinade will start working against you, turning the meat mushy instead of meaty, so I don't recommend marinating for any longer than 12 hours total.

On the Grill

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Grilling.

The last step is actually the easiest (and the most fun!): grilling.

There's one cardinal rule for skirt steak, and we've repeated it again and again: Use the highest heat possible. I mean smoking, blistering, painfully hot. Skirt steak is very thin, yet it tastes best when charred to the point of crispness. With your normal grilling temperatures, the center ends up overcooking before the outside has a chance to char. For the best results, add your steak to the grill only once the coals are at their hottest, or after the gas has had a chance to preheat until it can preheat no more.

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Sliced.

That's the only way you're going to get steak that's gorgeously charred on the outside, full of smoky, sweet flavors, with a center that's still pink and the fat just starting to soften and melt, lubricating the whole affair. I generally advocate using a thermometer, and, if you've got one, the very center of this steak should register 110°F or so when you pull it off (carryover cooking will bring it up to a medium-rare 125 to 130°F). But even without a thermometer, so long as the exterior is well charred, chances are good you're going to hit that final temp spot on. It takes a little more coal than usual, or a slightly longer preheat, but the results are well worth it. I mean, just look at this:

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Served.

It's almost enough to make a grown man forget about his crayons. I very happily discovered that if I set aside some of the marinade before adding the extra salt, it served as a not just decent but fantastic salsa for the meat, whether I decided to eat it whole with a knife and fork or stuffed into tacos with onions and cilantro.

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Taco.

One important detail: After the steak comes off the grill and rests for a minute to come to its final temperature, make sure that you slice it against the grain—that is, perpendicular to the very pronounced striations that appear in the meat. Failure to do this will leave long muscle fibers in your meat, making it feel rubbery and tough. (Read more about why you should slice against the grain here.) It will also instantly reduce any accumulated street cred you may have garnered from friends, family, and acquaintances to an effective operational level of zero, and you'll be forced to start building up that cred again from the beginning.

If there were a short list of foods that help increase your street cred when executed properly, carne asada would have to be pretty high up there. Now if only I could find a way to replace that fried ice cream and those frozen margaritas of my memory, I might finally be able to free myself of the shackles of my youth.