Can You Reuse Oil After Frying Fish For Other Things ?

Cooking oil is an indispensable part of everyday cooking. Many households or restaurants and eateries that want to save money have stored the remaining oil from the food processing process for the next cooking time. However, there have been many warnings that reusing cooking oil can change its chemical compounds, thus making it more harmful to the body. So how safe if you want to reuse cooking oil. Let’s refer to the following article “Can you Reuse Oil after Frying Fish?” to have a better overview!

What happens when you reuse cooking oil after frying fish?

What happens when you reuse cooking oil after frying fish
What happens when you reuse cooking oil after frying fish

According to a nutritionist:

Processed cooking oil should not be reused because grease easily oxidizes, becomes foul, and increases trans fatty acids which are extremely dangerous to your health. Overheating the oil or reusing the oil will change the texture of the fat. Forms new compounds that are less useful and, when ingested, can be harmful. In particular, avoid reheating cold pressed oils as they have periods of smoking. Vegetable oils such as mustard oil, rice bran oil, and canola oil… are very good for the body, but you should not use them again after they have been heated.

When you reuse cooking oil, it can create free radicals that are harmful to the body in the long run. Theme free radicals can cause cancer and damage your body. Oil reuse has also been linked to an increase in bad cholesterol levels in the body. Some other possible health risks include acid damaging the heart and throat.

How many times can you reuse cooking oil after frying fish?

If you want to reuse the oil again, make sure your oil is hot enough and hasn’t been heated too high enough to smoke. This means if you’re frying fish, and the oil is hot and smoking, throw it out.

At high temperatures, the oil in use will smoke – which means that the oil begins to deteriorate. If you turn the heat up too high, the oil will smoke very quickly and there is creolin in the smoke, which can sting the eyes.

When the oil is smoked, it will accelerate the deterioration of the oil, make them smell bad, and change color (the oil is black). Therefore, there is no recommended number of times you can reuse cooking oils or how many times you can reheat them, just be careful with the directions for that cooking oil. The best thing to do is to avoid reusing excess oil as much as possible, especially with oil that has been fried fish.

*** Read more: Can You Put Aluminum Takeout Containers In The Oven? [Answer]

Leftover frying oil and how to check the safety of the oil if you want to reuse it?

Leftover frying oil and how to check the safety of the oil if you want to reuse it
Leftover frying oil and how to check the safety of the oil if you want to reuse it
  1. If you want to store heated cooking oil, let it cool first. Then filter all fish scale residues out of the oil and store it in an air-tight container. If you don’t filter the residue, chances are your cooking oil will go rancid and spoiled.
  2. Close the bottle cap tightly, and store it in a cupboard with a closed door to limit light entering and cause the oil to spoil quickly. Store in a cool, dry place and use within one month.

Use foil to cover the entire glass bottle to seal. The foil has the effect of minimizing direct light on the oil, so the oil will be preserved for a long time.

  1. Oil degradation is the first point you should pay attention to. Some signs of deterioration may include foam on the surface, rancid odor, and thick, greasy, viscous texture.

Each type of oil has a different smoking temperature such as sunflower oil at 246 degrees Celsius, soybean oil at 241 degrees Celsius, Canal at 238 degrees Celsius, and olive at 190 degrees Celsius… Each time cooking oil is used again is each time the fuming temperature of that oil is reduced.

  1. Do not mix many oils when you want to reuse them. Oil should not be frozen.
  2. When cooking, please pour a moderate amount of oil, to avoid waste and reuse.

Why is the use of fried cooking oil many times likely to cause cancer?

Cooking oil contains many nutritional components and preservatives, and emulsifiers, … these substances will change at high temperatures and form substances harmful to health.

When frying for the first time, the nutritional components in the oil seep into the food. The substances in the cooking oil begin to change a little, so you will see the color of the oil change after frying. If you continue to use this oil to fry, the high temperature will make these substances continue to change, creating more toxic substances. Thus, toxic substances will be produced more and more while the nutritional components are gradually lost. Therefore, it is not recommended to use the fryer, again and again, it is best to use it only once.

Starting from the smoking temperature (average 180 – 250 degrees Celsius) the cooking oil will decompose and the chemical composition will change:

– The vitamins A and E in the oil are destroyed and replaced by toxic substances such as aldehydes, and fatty acid oxides… They can destroy the digestive system causing indigestion, headache, and dizziness…

– High temperature when frying will cause cooking oil to produce acrylamide, which affects the nervous system. Acrylamide is a potent neurotoxin that has adverse effects not only on the brain but also on the reproductive system. The fats in the oil are destroyed by oxidation and release acrolein, a toxic, carcinogenic substance.

Essentially, cooking oil will oxidize when exposed to air. The higher the temperature of frying oil, the more times it is reused, and the more toxic it is. Not only does the taste of the oil change, causing the dish to change its taste, but its safety for health is also gone.

*** Read more: Do Frozen Waffles Go Bad? Ways To Properly Store Waffles

The dangers of using cooking oil after frying fish

The dangers of using cooking oil after frying fish
The dangers of using cooking oil after frying fish

#1. Causing cancer

More and more research is showing how aldehydes – the toxic element – are created when you heat oil. Cooking food using cooking oil can also increase free radicals in the body, which can cause inflammation – the root cause of most diseases including cancer, obesity, heart disease, and diabetes. Street. High inflammation in the body can also lower immunity and make you more susceptible to infections

#2. Increased LDL cholesterol

Food cooked with oil that is used repeatedly can raise levels of LDL (bad cholesterol in the body). High levels of LDL cholesterol can increase your risk of heart disease, stroke, and chest pain. Avoid reusing cooking oil to avoid cholesterol-related problems.

#3. The stomach secretes more acid

If the burning sensation in your stomach and throat is becoming more frequent than ever, then frying oil could be the culprit. Avoid eating roadside snacks and fried foods, fast food…

Other health risks associated with eating foods in reheated cooking oil are Obesity, Weight Gain, Diabetes, and Heart Disease.

Use cooking oil completely instead of fat?

Fat does not contain harmful fats. Therefore, for good health when cooking, it is best to use both vegetable oils and animal fats. Animal fats provide lipids to build organs in the body. Provide cholesterol for the body although the amount is not much. Vegetable oils provide unsaturated fatty acids (omega3 and omega6).

Nutritionists recommend that normal healthy people, it is recommended to use vegetable oil and animal fat in parallel (children should eat in a ratio of 50 – 50). As for people with obesity, high cholesterol, blood fats, at risk of hypertension, diabetes, etc., only vegetable oils should be used to reduce the amount of animal fat in the body. People with atherosclerosis who have shown signs of cardiovascular disease should eat vegetable oil completely.

However, there is still a way to help you fry food perfectly without the need for frying oil. It’s an “air fryer” that helps retain nutrients without harming health.

Air fryers, also known as vacuum fryers, can reduce the amount of frying oil to ensure health. The pot will overcome the drawback of splashing oil when frying with a pan. This is an increasingly popular kitchen appliance thanks to its simple design. Helps optimize the method of frying without oil thanks to the heating mechanism of the bar (mayso wire). The cooling fan has the function of circulating heat throughout the surface of the food to help them cook evenly from the inside out.

*** Read more: How To Stop Rice Burning In Rice Cooker: Helpful Tips!

What type of oil should be used for frying fish?

You should choose an oil with a neutral flavor and high smoke point. Oils with a high smoke point are usually those that are more refined.

As their heat-sensitive impurities are usually removed through chemical treatment, bleaching, filtration, or high-temperature heating. The high smoke point is usually above 375 degrees F, because that’s the temperature you’d normally fry. Oils with high smoke points include canola oil, pure olive oil, avocado oil, vegetable oil, safflower oil, and peanut oil.

What type of oil should be used for frying fish
What type of oil should be used for frying fish


Storing cooking oil properly should be a priority for every cooking time. In addition, you can store cooking oil in crockery jars, and clean, dry glass bottles with tight lids. Above is our “Can you Reuse Oil after Frying Fish?” article on the issue of cooking oil. Hope they will help you to know more useful information.

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