As a chef instructor at a Le Cordon Bleu culinary school, there's nothing more inspiring than checking in my class' product order and finding that our fish for that day's recipes is unbelievably super fresh. Fabricating, cooking, and eating fish has always been something near and dear to my heart, and from a cook's perspective, fish and shellfish deserve a special level of respect when they are in pristine condition.
Last night, we received some amazingly "just out of the water" fresh flounder from the east coast. When they are small like the ones we got, about a pound and a half to two pounds each, they typically go by the name "fluke".These "flat-fish" are the funky looking ones you've probably seen before but haven't necessarily known what to make of them. I think of them as the Picassos of the fish world, with both of their eyes on the same side of their head. That set-up is due to the fact that they are bottom dwelling ambush predators, burying their flat, serving platter shaped bodies in the sand so that just their eyes stick up to keep on the lookout for food.
Since our flukes were so very fresh, I was able to take a few minutes to teach my students about the various signs they need to look for when trying to judge how long a fish has been out of the water. The first thing I like to talk about is how the fish smells. If it smells fishy in an unpleasant way, it's not fresh. It should smell like an ocean breeze (or a lake breeze if it's a freshwater fish). A hint of watermelon or cucumber aroma also is a good sign the fish was plucked from the depths recently. So get your nose close to the fish and breath deep! Then there are the gills; lift the gill plate behind the head and make sure the gills are bright red. If they are brownish or gray, the fish isn't fresh. Look into the creature's eyes...if they are clear and slightly bulging, you're in good shape. Cloudy and sunken is not what you want. Next, gently press your finger into the side of the fish. The flesh should feel firm and your finger shouldn't leave a depression. The skin should also be moist and shiny, not dry and shriveled. A bit of natural slime is a good thing...it helps the fish glide through the water, so don't be alarmed if it feels a bit slick.
If you pay attention to these simple freshness checks when purchasing whole fish, you're guaranteed to bring home and cook the best seafood you can find.