The Real Difference Between Fish Sauce And Oyster Sauce

Oyster sauce and fish sauce are both used in a number of cuisines to add a salty, savory, umami flavor to the dish, but although they both come from seafood products, they're quite different from one another. Traditionally, oyster sauce was made out of a reduction of the liquid in which oysters were poached (via Spiceography). However, commercially-produced oyster sauce may very well contain significantly less oyster concentrate and instead have extra ingredients such as sugar, salt, and soy sauce. It's thick and dark — it's a brownish-black color, and you may have to work a bit to get it to dissolve if it's called for in a recipe as part of a mixture. It's sweet and earthy tasting, although you would be hard-pressed to say it tastes like oysters, raw or cooked. 

Fish sauce, on the other hand, is pungent and is a staple of Thai and Vietnamese cuisines (via Cook's Illustrated). It's made from fermented fish (usually anchovies) and salt. It's a significantly thinner sauce than oyster sauce and has a reddish-brown tint to it. True oyster sauce, made primarily of oyster poaching liquid, is thinner than the mass-produced variety, but users find that it's still thicker than fish sauce.

Applications of fish and oyster sauce

Fish sauce can either be either used in the cooking process or as a condiment for soups and noodles. When it's used as a condiment, it's often mixed with chili peppers and lime juice. The same goes for oyster sauce, it's called for in many recipes and also often drizzled over vegetables such as Chinese broccoli or bok choy once the dish is finished or when it comes off of a dim sum cart.

If you're not a fan of fishy flavored things, you're probably going to be more sensitive to the taste of fish sauce. While oyster sauce tastes very faintly of the ocean, fish sauce smacks you in the face with its intensity (via Bon Appetit). After all, if you're taking one of the most potent-tasting fish in the sea and then allowing them to ferment, it should come as no surprise that the finished product comes out tasting so strong.