Salt-Crusted Beef Tenderloin (Lomo Al Trapo)

Wrap up a beef tenderloin with salt, spices, and a towel before throwing it directly in the coals and observe the magic. The Lomo Al Trapo is a show-stopping Colombian dish. A wine-soaked cloth covers this salt-crusted beef tenderloin, charred in the flames.

Cooking anything directly on a bed of hot coals is exciting and risky. Now, take a generally expensive cut such as beef tenderloin, wrap it up with salt and a towel and throw it in the coals. Do you trust me?

You should, as the Colombians have been cooking the Lomo Al Trapo for years. The name translates to “beef loin in a towel” so there are no surprises here. Traditionally a cloth of cotton is used, soaked with water, wine (red or white), or beer. The beef tenderloin is then wrapped in a substantial amount of salt inside of the towel, and thrown directly into the flames.

I’m sure you have so many questions, I sure did!

Why This Recipe Works

• Practically foolproof, just stick with the timing and temperature.
• The thick salt crust insulates the meat, keeping it moist while seasoning it.
• Very little cleanup, everything goes into the fire.
• An incredibly fun experience for the chef and guests, making memories.
• Timing is consistent and easy to plan for.

Lomo Al Trapo, Simple Process

The first time I came across this was on YouTube years ago, someone had been preparing it and threw it onto the logs in their fireplace. Obviously, I had to watch, anticipating a huge flare-up. Worse, the tenderloin could be completely ruined. They cracked it open and sliced, served, and everybody was so excited. Their beef was cooked well-done, but I was inspired to research more and understand how to pull this off.

Turns out this is pretty straightforward, so simple that it’s not even necessary to check the temperature of the fire if you’re timing it right. I have not tested cooking the lomo al trapo in a wood-burning fireplace, only on charcoal grills.

Very few ingredients

Less prep and cleanup? Absolutely, I’ll take it. The lomo al trapo mostly uses salt, spices are optional, so you’ll basically just need that. Research shows that fine grain salt works best but avoid table salt. Kosher Salt is highly recommended as it will not over-season the beef tenderloin, still creating the crispy shell.

Burning towels seems to be a common concern for most Americans, worried about toxins or particles coming into the meat. The 1/2″ salt crust prevents that from happening, encasing the meat entirely. Purchase hand towels that are 100% cotton with no dye, and you’ll be just fine. I’ve linked the ones I use below, which are very affordable and expendable to the flames:

Beef tenderloin is the only option if you’re looking to prepare the lomo al trapo in the traditional Colombian way. This incredibly lean cut soaks up the flavors from the salt and wood-fire, remaining incredibly juicy when you slice into it. Even if you cook it a little past your target temperature, it’s still packed with beefy flavors.

Whole beef tenderloin can be expensive and require a fair amount of trimming. You can ask your butcher to clean it up for you, which will save you some time and potential mistakes. I’ve also purchased pre-trimmed tenderloins online, which are incredibly juicy if you’ve picked a good provider. Omaha Steaks carries their Chateaubriand which is the fancy name for beef tenderloin. Theirs are wet-aged for at least 30 days, which increases the tenderness as well. Frozen or not, the quality is really nice for convenience.

Yes, that is a lot of salt. You’ll need quite a bit if you’re going to make a salt crust for the entire beef, protecting it from the direct flames that will consume it. The technique of salt baking is nothing new, used for fish, vegetables, and many various types of meat across the world.

Salt baking obviously seasons the meat thoroughly, applied to the beef immediately before you start the cooking process. Salt is also a moisture-sponge, and using it as a thick crust ensures that the juices drawn out of the beef do not evaporate. The flavor vault of salt ensures fairly even cooking as well, insulating the food from hot spots.

Scout’s Honor: This beef tenderloin is not too salty when you slice into it.

One full beef tenderloin will make up an absolutely huge cut of the lomo al trapo, but the challenge is finding a towel large enough for it. Sliced in two pieces, the beef fits perfectly in a majority of small cotton towels, also allowing you to experience the dish twice if you’d like.

Prepping the Lomo Al Trapo

I absolutely love it when recipes are incredibly simple and consistent, which is the beauty of cooking the lomo al trapo. The first step is to soak the towel for 20-30 minutes, giving you just enough time to trim the beef and light the coals.

The photos show the towel bright pink, soaked in red wine (used Malbec for this) but it’s not the only option. Aromas from the wine-soaked towel gently perfume the beef inside. It’s also traditional to use white wine, beer, or even simply water.

Lay out the towel after it’s soaked and wrung, pouring out a heavy amount of salt. Sprinkle the salt with recommended spices and roll the beef tenderloin to make sure each side picks up some of those flavors. Put some of the salt on the top of the beef, and carefully roll to make sure it’s evenly coated. Tie up the ends of the towel to form a knot, you may also use butcher’s twine if the towel is not large enough.

Cooking the Lomo Al Trapo

Take your carefully wrapped beef present and throw it in. Well, be gentle. Knot-side up at first, which helps build that salt crust on the bottom as it’s a slightly thinner barrier of cloth.

You will cook it for 9 minutes, flip, wait another 9 minutes and check the temperature with a probe.

You honestly don’t need to use a probe, but for the picky grillers (like myself) I want to make sure it’s at medium-rare if possible. Carefully insert the probe through the salt crust towards the middle of the beef and check the temperature. Don’t make a second hole if you need to verify more than once.

When the beef is ready transfer the lomo al trapo to a metal platter to rest. I’ve watched people burn their countertops and wooden cutting boards, not thinking about the fact that there are hot embers stuck to the cloth. The beef only needs to rest for a couple of minutes in the salt crust, otherwise, it will continue to cook.

In the moment of truth, you need to crack the charred towel and salt crust to reveal the steaming beef tenderloin. Wipe the sweat off your brow, and take a generous sip of wine. It’s time to eat.

Frequently Asked Questions

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