The Common Marinade Mistake That's Ruining Your Tuna

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When it comes to cooking juicy steaks or tender briskets, you've probably got your marinade recipe memorized. Logic would tell you that applying that same delicious concoction to a cut of tuna would produce the same appetizing results — but logic would be wrong. We spoke with seafood chef and Sea Tales founder Bart van Olphen, the author of cookbooks including "Veggies & Fish" and curator of the online "Ocean Cookbook," who says that a common mistake that will ruin your tuna is adding acids to the marinade.

Van Olphen advises caution when marinating tuna, saying, "Acid ingredients such as lemon, lime or vinegar will influence the color of the raw flesh of the fish, it becomes opaque very quickly." He therefore suggests using a marinade without acidic elements. However, he does say that if you go easy on the acids, it could work, suggesting, "Or you mix them with oily ingredients to neutralize the acidity and make it less aggressive."  

Despite its often-negative effect, there are ways to add acidity to tuna without ruining it. Van Olphen simply says, "When I do use citrus, like lime juice, I usually add it right before serving as a finishing [flavor] rather than marinating the fish in it"

Tuna has tender flesh that doesn't necessarily require much marination. Chef van Olphen says, "When it's responsibly sourced and fresh, it's already perfect. Your marinade should simply enhance that." If you do use a marinade, it should be mild. He says, "Tuna has a very delicate taste, and you don't want to lose this elegancy while marinating." Van Olphen prefers "oily marinades such as olive oil with oregano, thyme, garlic, salt and black or white peppercorns," other times switching to "sesame oil, soy sauce, ginger, mirin and garlic." He says, "These marinades not only give the tuna nice flavor [but] also protect the fish while cooking."

Once you've figured out the ideal marination for your tuna, pay attention to how long it brews. Van Olphen reminds us that the "longer you marinade, the more intense the flavor," so he recommends not marinating for too long — if you do add any acid to your tuna marinade then only leave it for 15-20 minutes. Without acid you can go longer — up to about 2 hours. The chef's final piece of advice is on temperature, saying, "Always marinade your fish in the fridge, as it protects the texture."

As for how to cook the fish, follow one of our 13 best tuna recipes and take our advice on the best ways to cook tuna steak without it drying out. Don't forget this easy prep tip that will help you cook tuna evenly, which is to take the fish out of the fridge to come to room temperature before quickly cooking it.