Temperature and Doneness when Cooking Fish - Section 2: Why Fish Cooks Differently: Understanding the Basics

Fish muscle is built like layers of tissue paper held together by thin sheets, while meat muscle resembles rope fibers bundled tightly together. This is why properly cooked fish flakes apart so easily along natural lines, while meat needs to be cut.

These short muscle fibers mean fish cooks much faster than meat and continues cooking even after you remove it from heat. Fish proteins begin to coagulate around 120-130°F (48 - 54°C), much lower than meat proteins, which is why fish can transform from perfectly moist to dry in just a minute or two.

Coastal cultures have understood this intuitively for centuries – Mediterranean fishermen knew to cook their catch gently, while Japanese chefs developed techniques that barely warm fish throughout. Understanding this fundamental difference helps explain why the aggressive heat that works for a steak will ruin a delicate piece of sole.