Citrus Herb Marinade for Tuna Steaks

Why This Citrus Herb Marinade for Tuna Steaks Works

Once the tuna sits in the citrus herb marinade, the juices from the orange, lemon, and lime start to soak into the surface of the fish. The acid in those juices gently loosens the outer layer of the tuna, so it doesn’t tighten up as much when it hits the hot pan or grill. Instead of drying out fast, the outside stays a little softer and holds onto more moisture.

Olive oil coats the tuna and forms a thin layer of fat around it. During cooking, that oil keeps the heat from hitting the fish too harshly, so the inside stays tender while the outside cooks. Soy sauce and salt move into the tuna along with the juices, so the seasoning isn’t just on the outside. Garlic, parsley, and cilantro cling to the oiled surface, so they stay on the fish as it cooks instead of sliding off. By the time the tuna is done, the inside stays moist and the outside has a bright, well-seasoned crust.

Mistakes To Avoid

Letting the tuna sit in the marinade for too long, especially past 2 hours, lets all that citrus start to “cook” the surface of the fish. The outside turns firm and a bit chalky before it ever hits the pan or grill, so it can end up dry and tough while the inside is still fine.

Pouring the marinade over very wet tuna, straight from the package without patting it dry, waters everything down. The oil and juices slide off instead of clinging, so the fish goes into the pan with a thin, weak coating and can taste flat and a little bland on the outside.

Using high heat on a pan or grill that isn’t properly preheated often causes sticking and torn pieces. The tuna surface doesn’t sear fast enough, so it rips when turned, losing its outer layer and juices and ending up ragged and a bit dry.

Adding a lot more soy sauce than listed throws off the balance of liquid and salt. The marinade becomes darker and sharper, and the tuna surface can tighten and firm up too quickly on the heat, giving it a slightly rubbery bite.