Frying catfish correctly is an art. A simple art.
Fried catfish joins a long, sad list of regional southern dishes that are often done wrong: barbecue, grits, and fried chicken being a few other examples. It doesn't need to be this way. Frying catfish right is a pretty simple procedure, as long as you take these few suggestions to heart.
Step 1: Before You Fry
The work you do prior to frying will be decisive. For frying catfish, your biggest concerns will be the size of the fillet, and careful preparation of the breading.
Frying the whole fillet is a bad idea. Everyone knows that a larger fillet takes more time to cook, and time is always a liability in frying. Your fillet should be cut into small chunks or strips, and washed thoroughly before applying the breading. Whichever you decide, make sure the fillet is cut into thinner pieces.
The breading should be a mixture of cornmeal and a leavening agent, either baking soda or yeast. The leavened mix will make the breading crispier once it comes out of the fryer. For the best crust, you should apply two coats of breading. You'll need an egg wash for this, but that's pretty easy to make--it's just a mix of egg yolk and milk that adds flavor and holds the breading together. After washing your fish, apply a thin coat of breading. Shake off excess and then brush with egg wash until you have an even layer. Finish it off with another coat of breading. The layered approach helps the breading stick better, ensuring a thick, even crust with no cracks.
Step 2: The Fryer
Peanut oil is preferred, Crisco and lard are good alternatives for the peanut-allergic. Sources are split on whether to use a deep fryer or a dutch oven, but that's a matter of taste and what's on hand. You just want to make sure that you're deep frying, and that you're not using canola oil.
The ideal temperature for the oil is 350 degrees; not lower than that, and not too far over it. This is important, because the temperature of the oil influences how much gets absorbed. Soggy, oily catfish is usually a result of cooking at too low a temperature.
Step 3: Resting and Serving
It's pretty easy to tell when a piece of catfish is done frying. It will float to the top when it's nearly done. Once the crust is golden brown, remove it from the oil and set it on a paper towel. Then comes the critical final step: dabbing the excess oil. A lot of oil is absorbed while the fish is resting, and you need just the right amount to soak in. Too much gets you soggy, unpleasant fish, while too little leaves you without the flavor and mouthfeel that's the entire point of frying.
This takes a practiced touch, and you'll need to experiment a few times to find the right balance.