How to remove the earthy smell of freshwater fish

We all know that there are many types of fish, and freshwater fish is one of the more popular edible fish. Many people often eat freshwater fish. When cooking freshwater fish, many people will find that there is an earthy smell on the freshwater fish, which is a very normal phenomenon. So why does freshwater fish have an earthy smell? Let's take a closer look!

Why do freshwater fish have an earthy smell?

The smell of fish is most closely related to their living environment. Everyone should know the news that "carp is rampant in the United States." In addition to having many bones and being difficult to cook, the main reason why carp is "unpopular" is because it has a relatively strong earthy smell, and the biggest source of this earthy smell is its living environment.

To be precise, it is because there are often some single-celled phytoplankton (cyanobacteria, diatoms) in the water environment where freshwater fish live. These algae produce semi-volatile earthy smell substances in the metabolic process, which fill the entire water body. These earthy smell substances are highly lipophilic and can be easily absorbed from the fish's body surface, and then transferred to the fish's subcutaneous fat and muscle fat, so fish living in freshwater will accumulate these substances in large quantities. We can simply and roughly understand that the algae use earthy smell substances to "pickle" the freshwater fish.

What to do if freshwater fish has an earthy smell

The solution is given from two perspectives, mainly focusing on the perspective of home cooking:

From the perspective of freshwater fish farming:

To remove the earthy smell of freshwater fish, we can adjust the balance between soil and microorganisms, drain and change water regularly, keep the water clearer, and control things like blue algae and diatoms. Secondly, we can also increase the iron content in the feed to enhance the hemoglobin and metabolic function of freshwater fish, so as to reduce the accumulation of earthy smell in the fish body. Although this will increase the breeding cost, the advantage of "no earthy smell" alone is enough to become a selling point.

From the perspective of home cooking of freshwater fish:

What we ordinary consumers are more concerned about is definitely how to remove the earthy smell when cooking a freshwater fish at home. In fact, this is not difficult. There are many methods, and the effectiveness varies. Let's share them below.

1. Slow method

If you buy a freshwater fish but are not in a hurry to eat it, we can keep it in clean water. As we mentioned earlier, the earthy smell is mainly caused by the algae metabolites that "pickle" the fish. If we use clean water to feed it for a few days, the fish will slowly metabolize the earthy smell in its body, and its earthy smell will naturally be greatly reduced.

Advantages: It is relatively hassle-free and trouble-free. Many freshwater fish can survive for several days by simply throwing some vegetable leaves and rice into them. In addition, this method does not rely on seasoning to remove the earthy smell, so it can be prepared in a lighter way, such as steaming.

Disadvantages: The fish will become thin easily and it takes time. And sometimes I dare not use this method, for example, when the fish I bought is already half dead, if I suddenly change the water and feed it, it will die again, which is not worth the loss.

2. Quick method

When we buy fish, many fishmongers will help us kill the fish. After all, practice makes perfect and they are very quick and easy in handling live fish. But in this case we have to use other methods to remove the earthy smell, which are basically some little tricks for handling fish in the kitchen.

(1) Remove earthy odor by pretreatment:

① There is always some mucus-like substance on the surface of freshwater fish. It must be rinsed thoroughly after descaling. You can sprinkle a little flour or starch on it, and then rub it gently to remove it. The flour will "peel off" the mucus.

② The blood and internal organs of the fish should be removed, as these substances are the main places where earthy smell substances are retained. In addition, the "fishy line" and "fish teeth" that are more easily contaminated with odors should also be removed.

③After the fish is gutted and cleaned, you can soak or marinate it in light salt water, cooking wine, light vinegar water, etc. Since the earthy smell is "marinated" by algae metabolites, we can remove it in a similar way.

(2) Remove earthy smell during cooking:

The most commonly used ingredients are onions, ginger, garlic, and peppercorns. In addition to pickling to remove odors, using hot oil to bring out the aroma of spices can also cover up the remaining earthy smell of freshwater fish.

Secondly, freshwater fish can be cooked in high temperature or with a stronger flavor. For example, braised fish can be fried or even deep-fried before cooking. As we mentioned earlier, the earthy smell of freshwater fish is "semi-volatile", so the residual smell will evaporate and disappear under high temperature.

Tips for removing the fishy smell of freshwater fish

Soak to remove odor

Soak the cut fish pieces in light salt water for an hour, then rinse and marinate. Alternatively, cut the fish meat, add appropriate amount of salt and cooking wine to mix to remove the slime, rinse and marinate. This step can also remove some of the fishy smell.

Pickled to remove fishy smell

In addition to adding salt when marinating, you can also add an appropriate amount of cooking wine, light soy sauce, pepper and ginger slices. You can also add white vinegar and white wine to marinate to remove the fishy smell, because the alcohol will evaporate when heated, taking away the fishy smell. Alcohol can also enhance the flavor of the fish with acetic acid.

Oil to remove the fishy smell

When the fish is fried at high temperature, it can remove some of the earthy smell and lock in the moisture of the meat. Freshwater fish can be cooked by frying or deep-frying.

Seasoning to remove fishy smell

When braising freshwater fish, you can stir-fry ginger slices, minced garlic and scallions to bring out the aroma and cook them together with the fish. When making pickled fish or boiled fish, add oil at the last stage to bring out the aroma of minced garlic and chili. This step is to add flavor to the fish and remove the fishy smell.