How to Clean a Flounder (Step by Step Guide)

Learning how to clean a flounder by yourself is so rewarding and fulfilling. I love to cook flounder because of its high protein content and low levels of calories and fats.

Before cooking flounder, you will need to thoroughly clean it to remove stubborn innards, outer scales, and other unwanted organs.

Many people find fillet flounder, halibut, and other flatfish species challenging because they require a unique technique, unlike other fish. Even so, the process can be easy when you follow the correct procedure.

Here is a step-by-step guide to help you filet fresh flounder like a pro.

Table of Contents

Items Needed to Clean Flounder

A sharp filet knife
Filet board, cooler lid, or cleaning table
Fresh-water

The Process

Scale the Flounder

Usually, flounder is covered in a layer of clear slime to keep them safe in the water. Scaling the fish will allow you to remove the slime layer and the scales.

To clean the flounder, you will need to start by placing it on a flat, hard-cutting surface to make filleting easier. Then, hold the fish firmly by the tail using the non-dominant hand. However, if the slime is milky white, the flounder’s meat could be spoilt. Discard it immediately.

You can place a plastic bag or newspaper over the cutting board to minimize the mess and make cleanup easier.

The next step is to hold the filet knife with the blunt side lying on the flounder’s skin. Then drag the knife across the fish, from the tail to the head. Repeat this process until all the slime and excess scales fall out.

Remember to keep rinsing the knife to remove stuck slime and scales and keep the blade effective. However, if you have a fish scraper, use it for scaling. It works better than the back of a knife.

Once you’ve removed the slime and scales from one side, flip the fish and scrape the other side. Then rinse the flounder under running water on both sides.

Rub the fish gently with your hands to get off the stuck scales. The skin should not feel slick or slimy. If it does, scale again until you get a clean feel.

Cut the Flounder Fillets

Make a deep incision behind the head of the fish, from top to bottom. Then using a sharp knife, cut a vertical line through the skin near the pectoral fin and past the side fin. But remember, the knife should reach the bones but should not cut through them.

Repeat this process on the other side of the fish. Then, start filleting from either side.

Locate the flounder backbone – it runs from the gills down the middle of the fish to the tail. Then insert the blade under the skin, along the backbone.

Cut the fish along the rib in a lateral line, from the gill plate to the tail, until the fillet separates from the backbone, leaving the meat attached to the outer edges of the carcass.

Ensure that you work from the center vertical line as you go outwards around the edge of the fish to the pectoral fins and as you drag the knife, keep lifting the side you are cutting.

Hold the fillet meat to separate it from the bone and peel it backward. Remember, it should only be attached to the outer edges of the carcass.

While peeling the fillet away from the carcass, you should see the spine and ribs of the fish. If you can’t see them, it means that you’ve made a shallow cut.

The next step is to remove the flounder fillet from the fins on both sides, starting with the top two flounder fillets and then the white side.

Note that if you want to cook the fillets without skin, you can remove them. You need to carefully insert the tip of the knife under the skin at an angle and work it across the fish. Continue until the skin separates from the meat.

Peel off the remaining sections of ridged fin meat on the outside edge, then rinse the whole fonder under a steady stream of water.

You can cook the meat immediately or store it in a Ziploc bag in the refrigerator or freezer until later.

How to Gut a Flounder?

Cleaning a flounder goes beyond removing the slime layer and scales. It involves gutting the fish through the following key steps:

Remove the intestines and the entrails alongside other parts of the fish that are not fit for consumption. Doing so minimizes messes created when eating fish, enhances taste, eliminates foul odor, and extends the storage life of the fish.

Open the head of the fish by pushing your index finger between the jaw and gills.
Remove the gills using your index finger or thumb. To effectively remove all gills, cut around the bottom of the jaw along the joint.
Make a deep incision on the fish’s underside, close to the jaw. Ensure that your knife is very sharp for this purpose.
Using your hands, open the incision and pull out the insides, including the intestines, kidney, liver, and other organs.
Remove stubborn innards with a spoon and wash the fish in plenty of water.

Cooking the Flounder

The easiest way to cook this fish is in a frying pan.

Drench the flounder in flour, heat some oil or butter in a pan, and place your fish. Fry it on both sides until golden brown, then season with some salt and enjoy.

After drenching it in flour, you can place it in a baking dish and bake it in the oven.

Another fantastic way of cooking flounder is by first marinating it with your preferred seasoning and spices. The common ones include; soy sauce, salt, garlic powder, and pepper. Then, you can poach, sauté, grill, bake, or fry. Cooked fillets have a phenomenal taste!

Regardless of how you prepare flounder or halibut, the most important thing is to ensure they are clean.

Wrapping Up

When cleaning fish like flounder or halibut, always remember that each side of the fish should be segmented into two parts.

The spinal column should be the dividing point. Otherwise, you will not extract as much meat as required.

The process of filleting a flounder is quick and fast when done properly.

Diana Nadim

Fishing Expert

Diana began fishing at the age of seven, as it has been a long-time family tradition. From catching small bullheads to catching strippers on the backwaters of Bighorn, she loves to get out in the wild and have a marvelous day on the water. Her dad was an expert angler, and he taught her fishing along with her two siblings. They used to go to the Bighorn River in Montana and Henry’s fork, Idaho. As a pragmatic person, she is obsessed with creating well-researched and practical guides and reviews of the best fishing methods and gear.