Soy Sauce (Best Option)
1 teaspoon per 1 tablespoon of fish sauceSoy sauce contains glutamates that provide umami similar to fish sauce, enhancing the flavor complexity of the pound cake without introducing fishy notes. Its liquid form also integrates well into the batter without affecting moisture balance.
When using soy sauce, reduce any additional salt slightly to avoid over-salting. Use light soy sauce to prevent darkening the batter excessively.
Compared to fish sauce, soy sauce offers a milder, less pungent umami, resulting in a subtly enhanced flavor that complements the cake's richness without overpowering it.