Reusing Cooking Oil: Rules and Exceptions


No matter if you are in a rush to have a tasty meal or trying to save some money, reusing oil is the way to go. However, it seems like opinions are divided — some people say it’s completely fine while others say it should be avoided at all costs because it’s bad for the health. Here’s what you need to know.

When it comes to reusing oil, there are rules and exceptions. The good news is that there are only a couple of very important things that you have to keep in mind before attempting to reuse oil:

  • Make sure that the oil has a high smoke point.
  • Check that the oil doesn’t look cloudy or smell rancid.

Alas, the things to take into account in terms of reusing oil do not begin and end there.

There are a few more things to consider before reusing oil for your peace of mind and your taste buds’ happiness.

Some of them include: which foods you can cook in it afterward, how long can you keep it once used, and where you should keep it.

Below are some of the most crucial things about this matter for keeping your culinary creations and health out of harm’s way.

High Smoke Point vs. Low Smoke Point

cooking french fries

Some oils are great for frying and deep-frying. Other oils are best for dressing purposes only.

It all depends on their various qualities.

Oils ideal for cooking purposes, especially using high heat, can be reused several times. In some instances, they can be used more than eight times. This is especially true if they are replenished with some fresh oil.

The same cannot be said for some oils.

As a matter of fact, it is a terrible idea to expose certain oils to high temperatures. Needless to say, they are not good for cooking and should not be reused.

Before you decide whether to reuse or throw away oil, it’s not enough that you take a look or whiff of it. You should also establish if the oil has a high smoke point or a low smoke point.

Knowing the oil’s smoke point oil will give you an idea if it’s something that you can use over and over again or should be disposed of after it’s been used.

What is a smoke point?

Also called the burning point, the smoke point is the temperature when oil starts to burn and produce smoke. The smoke point of some oils can be as low as 325°F. The smoke point of some oils can be as high as 520°F. Oils with high smoke points are best for cooking, especially frying and deep frying.

To save food from looking and tasting burnt and keep your health in tip-top shape, too, it’s a good idea to use oils with high smoke points for cooking.

Unfortunately, cooking oil makers do not indicate the smoke points of their products.

Failure to use oil right for your cooking needs can lead to disastrous results not only in your kitchen but also inside your body.

According to health authorities, cooking with oils with low smoke points can wreak havoc on your health. This is true even if you don’t put anything that’s cooked in it in your mouth.

Let’s take a look at some of the reasons why you should avoid cooking with oil with a low smoke point…

Increased lung cancer risk

deep frying

Whether oil has a high smoke point or low smoke point, it is bound to produce smoke at one point. The smoke produced by oil when exposed to high temperatures is called cooking oil fume (COF).

The problem with COF is that it is linked to lung cancer. It doesn’t come as a surprise since COF contains carcinogenic compounds.

In layman’s terms, carcinogenic compounds are compounds that can cause cancer in humans. People in the US that are at high risk of lung cancer due to COF are Chinese immigrants and those working in restaurants.

However, you don’t have to be a restaurant worker to end up with lung cancer as a result of exposure to COF.

If you cook and inhale fumes produced by oil all the time at home, your lungs may be in grave danger!

Increased heart disease risk

It’s no secret that a diet that’s high in fried foods, particularly unhealthy ones such as those that you can get from fast food joints, can put your heart and the rest of the cardiovascular system in peril.

Health authorities say that frying foods in oils with low smoke points causes certain compounds to come into being. The problem with these compounds is that they are linked to heart disease.

They may endanger your heart by causing inflammation inside the body. One of the many risk factors for heart disease is inflammation.

Besides heart disease, eating foods fried or deep fried in oils with slow smoke points may also put you at risk of suffering from dementia and all kinds of cancer, say many studies.

The takeaway: Just because oil has a low smoke point doesn’t mean it is unhealthy. The fact is that most oils with low smoke points are some of the healthiest on the planet.

However, if they are used for cooking purposes, they may do more harm than good. When shopping for oil for cooking, opt for something with a high smoke point.

Different Oils and Their Smoke Points

Since cooking oil makers do not bother to indicate on the packaging whether their products have high smoke points or low smoke points, let us take the initiative to get to know more about the oils supermarkets are selling.

Below, you will come across a list of different oils and their respective smoke points. There is no need to memorize the smoke points of every cooking oil there is.

All you have to do is keep in mind your reason for buying a particular type of oil. You may also buy a couple of oils — one is for cooking, and the other is for dressing or another purpose.

Here’s the list of oils with the highest to the lowest smoke points:

OIL NAMESMOKE POINT
Refined avocado oil520°F
Safflower oil510°F
Rice bran oil490°F
Pecan oil470°F
Refined olive oil465°F
Light olive oil465°F
Palm oil455°F
Soybean oil450°F
Peanut oil450°F
Corn oil450°F
Refined coconut oil450°F
Sunflower oil450°F
Rice bran oil450°F
Almond oil430°F
Hazelnut oil430°F
Macadamia nut oil425°F
Cottonseed oil420°F
Refined sesame oil410°F
Pine nut oil410°F
Canola oil (rapeseed oil)400°F
Cashew oil400°F
Grape seed oil390°F
Red palm oil (dende oil)380°F
Unrefined avocado oil375°F
Virgin avocado oil375°F
Unrefined sesame oil350°F
Pumpkin seed oil320°F
Walnut oil320°F
Pistachio oil250°F
Mustard oil250°F
Flaxseed oil225°F
Wheat germ oil225°F

The higher the smoke point of oil, the better it is for frying and deep frying. The majority of foods are fried between 350°F to 450°F.

So, in other words, it is a good idea to stick to oils with smoke points of 350°F or higher if you are planning on using them for cooking involving high temperatures.

Many healthy oils have low smoke points. Some very good examples are pumpkin seed oil and flaxseed oil. It’s true that they make for tasty and nutritious dressings.

However, they make for terrible cooking oils.

In addition, most oils with high smoke points are refined. Some common examples are refined avocado oil and refined olive oil.

If you are a health-conscious individual, refined oils may not be your best option.

This is exactly why your choices of oils that can be used for frying or deep frying without any trouble may be quite limited.

What are refined oils?

Refined oils are oils that are more filtered and strained than unrefined oils. Most of the time, refined oils are exposed to heat, although not to the point where health-damaging chemicals are produced. Because of the processing they go through, refined oils have reduced flavor and nutrient content.

It’s very much likely for you to have heard or read that refined oils are not good for the health. As a matter of fact, some people suggest that they should never be used for cooking altogether.

cooking oil bottles

However, according to health authorities, refined oils are safe for cooking. It was mentioned earlier that most refined oils have high smoke points.

This makes them perfect for frying and deep-frying. Using refined cooking oils for high-temperature cooking is better for you than using healthy oils with low smoke points for the same purpose.

But for low-temperature cooking or raw applications, it is a great idea to opt for unrefined oils.

The list of oils and their smoke points above, by the way, consists of vegetable oils only. Put simply, vegetable oils are oils extracted from various plant sources.

Some common examples are nuts and seeds, although vegetable oils can also come from other plant parts, such as fruits and the bran of grains.

Besides vegetable oils, there are animal fats, too. It’s not uncommon for fast food joints to use animal fats instead of vegetable oils. That’s because animal fats are cheaper. What’s more, they have high smoke points, too.

Let’s take a look at some animal fats and their respective smoke points:

OIL NAMESMOKE POINT
Ghee (clarified butter)450°F
Beef Tallow400°F
Lard (pork fat)375°F
Schmaltz (chicken fat)375°F
Duck Fat375°F
Goose fat375°F
Goat fat370°F
Margarine325°F
Butter300°F

When it comes to frying, deep-frying, and other high-temperature cooking purposes, animal fat makers believe that animal fats are superior to vegetable fats.

They agree that it’s all because of the fact that animal fats are more stable than vegetable oils when exposed to high temperatures.

So, in other words, frying or deep frying with them won’t expose you to by-products linked by health authorities themselves to some serious problems, including cancer and heart disease.

If you are a budget-conscious individual, you will find that animal fats are better for your pocket. Besides being cheaper than vegetable oils, animal fats generally have longer shelf lives, too.

And by the way, foods cooked in animal fats tend to taste better than foods cooked using any other oils.

Unfortunately, animal fats are not the perfect cooking oils. For instance, they are high in saturated fat.

Health authorities say that a diet that’s high in saturated fat can raise low-density lipoprotein (LDL) cholesterol levels.

You don’t want that to happen because having high LDL cholesterol levels is linked to heart disease.

Animal fats are high in calories, too. If you are a figure-conscious individual, cooking with animal fat, especially using them for frying and deep frying unhealthy foods, can cause your waistline to expand uncontrollably.

How to Reuse High Smoke Point Oil

First things first: Never reuse cooking oils with low smoke points!

Reusing them will not only make foods look, smell, and taste burnt but may also put your health in grave danger.

If you are planning on reusing oils to save both time and money, make sure that you opt for cooking oils with high smoke points.

As a general rule of thumb, if the oil has a smoke point of 350°F or higher, you may reuse it. Otherwise, replace it after cooking with it to protect your gastronomic masterpieces and health, too.

Do not use oils with very low smoke points for cooking — they are best for raw applications, such as dressings.

What’s so nice about cooking oils with high smoke points is that you can reuse them at least eight times.

You can even reuse them more than eight times if:

  • They have very high smoke points.
  • They are replenished with some fresh or unused oil.
  • They are used for cooking clean-frying items.

Speaking of which, just about anything that isn’t battered or breaded is considered clean-frying food. It means that it doesn’t cause oils to become cloudy or collect gunk or burnt bits of ingredients.

Reusing cooking oils after cooking battered or breaded items in them is fine, too. As a matter of fact, they can be reused three to four times.

However, there are some steps that you need to take before reusing them. It’s a great idea to carry out these steps, too, after cooking clean-frying foods in cooking oils.

Here are the things you should take before reusing oil…

Allow oil to cool

After cooking with oil, it’s a must that you allow it to cool to room temperature before you prepare it for reusing later. It’s for the obvious fact that it will help considerably lower your risk of ending up with burns.

Remove solids from it

deep frying meatballs

Once oil is already at room temperature, it’s time to get rid of solids it obtained from previous use.

Allowing solids to remain in it is a terrible idea — they will cause food that you reuse it for to smell and taste burnt! So, before reusing oil, see to it that it’s completely free of anything that is swimming or floating in it.

To remove solids in oil, pour it through a fine-mesh strainer.

Pairing a fine-mesh strainer with a piece of cheesecloth or a coffee filter is recommended.

This will make sure that even the tiniest bit of food or ingredient won’t make its presence known when you reuse oil.

Lining a strainer with a piece of cheesecloth or a coffee filter will take up more of your time alright. But it will do a better job.

Store used oil the right way

Once oil is rid of any solids, store it in a cool and dry place.

Whether used or unused, cooking oils should be placed where they are protected from heat, air, light, and moisture. Otherwise, they will go rancid faster.

Since used oil has been exposed to the elements already, failure to store it the right way can make it go bad quicker.

Reusing Oil After Deep frying

After using oil for deep frying, let it cool to room temperature completely. Strain with a fine-mesh strainer, preferably lined with a piece of cheesecloth or a coffee filter. Store oil after deep frying in a cool, dry place. It is a good idea to keep it in an airtight container to extend its life.

No matter if oil is used for frying or deep frying, it’s a must that you follow the above-mentioned steps on reusing oil.

Storing used oil the right way can make it last for up to three long months. This is excellent news, most especially if you have a deep fryer and you like using it on a regular basis.

But to make sure that used oil will be of service for a really long time, see to it that you use the right deep fryer oil storage container for it.

Here are some of the best-selling deep fryer oil storage containers available on the internet…

Cambom Bacon Grease Container

Wrought iron is more protected against rusting than pure iron. However, it doesn’t mean that it is impervious to rust.

The good news is that the Cambom Bacon Grease Container is not only made from wrought iron — it also has a non-stick coating inside and outside. Needless to say, rusting should be the least of your worries.

Capable of storing up to 44 ounces of used oil, the product comes with a removable fine-mesh strainer out of stainless steel. The included lid helps keep oil off-limits to dust and dirt.

If you are a clean freak, rejoice! That’s because the Cambom Bacon Grease Container ships with an anti-slip coaster tray that helps prevent accidental spills.

In addition, the container comes with a small spout design that allows for trouble-free pouring of its content into a deep fryer or any other cookware.

Chihee Oil Strainer Pot Grease Can

Out of food-grade stainless steel, you can rest assured that the Chihee Oil Strainer Pot Grease Can will help keep used cooking oil from being contaminated with rust and bacteria.

Thanks to its lid, used cooking oil can be protected from collecting dust and dirt until the next frying session.

Every part of the product is made of stainless steel, including the removable fine-mesh strainer. According to its maker, the included strainer is so fine that there is no more need to line it with a piece of cheesecloth or a coffee filter.

You can store up to almost 68 ounces of used cooking oil in the Chihee Oil Strainer Pot Grease Can. However, the maker suggests storing only 61 ounces of oil in it. To prevent unnecessary spillages, the product comes with a spout, an ergonomic handle and anti-slip coaster.

Ayesha Curry Bacon Grease Container

Do you want the creation of a popular cookbook author in your kitchen?

Then the Ayesha Curry Bacon Grease Container is the one you should consider placing in your shopping cart. Besides twilight teal blue, it is available in other colors, too. Some of them are basil green, brown sugar, and French vanilla white.

Enamel on heavy gauge steel construction helps make the product not only look eye-catching but also resistant to rust and stains — nothing can mar the vintage design printed on the outside.

Because it has a four-inch diameter, cleaning the used cooking oil container is a breeze.

Unfortunately, the Ayesha Curry Bacon Grease Container does not ship with a fine-mesh strainer, unlike the products we talked about earlier. However, there is no denying that it’s the clear winner when it comes to looks.

FAQs on Using and Reusing Oil

Now that you know which oils have high smoke points and which oils have low smoke points, it’s time to talk about some real-world applications of using and reusing oils.

There is no point in getting your hands on oil that you can reuse over and over again if you do not know how to use it properly.

While it’s true that some oils can be reused, it’s still a must that you use them the right way each time.

This is when the sheer importance of answering some frequently asked questions (FAQs) on using and reusing oils comes in.

By having a few pressing questions that you might want to be answered but are too embarrassed to ask, you can have a pleasing time in the kitchen every single time. Your epicurean creations will be epic, too!

Does used cooking oil need to be refrigerated?

Besides placing it in a cool, dry place, used cooking oil can be refrigerated, too.

However, it should be transferred to an airtight container to keep it from absorbing refrigerator odors. Some vegetable oils become cloudy in the fridge, but they will be resolved when they return to room temperature.

Can I freeze cooking oil to extend its life?

Cooking oil can be kept in the freezer in its original container. It can keep for two long years in the freezer without changing its consistency or usefulness. If it is no longer in its original container, cooking oil should be transferred to an airtight container before storing it in the freezer.

Can I leave oil in my deep fryer?

It is possible to leave oil in the deep fryer. However, it is recommended to filter cooking oil once it’s at room temperature. This is done to remove solids that can cause oil to go bad when they spoil. To maintain the quality of cooking oil, it’s a good idea to transfer it to an airtight container.

How often should I change oil in the deep fryer?

Oil in the deep fryer should be changed after around eight uses. This is especially true if oil has a high smoke point, which is what’s recommended for use with a deep fryer. Oil in the deep fryer should be strained after every use.

Storing it in an airtight container between uses is recommended.

Is it safe to use cooking oil left out overnight?

Cooking oil left out overnight is not safe to use if it’s left unfiltered and uncovered. That’s because solids in it can harbor bacterial growth, which can have an effect on the digestive system and overall health, too.

Oil should be strained and transferred to an airtight container after using it.

How do I dispose of cooking oil environmentally?

To dispose of cooking oil in an environmentally friendly way, take it to or have it picked up by a used cooking oil collection and recycling company. Otherwise, place it in a non-recyclable container and dispose of other household waste items. Small amounts of vegetable oil can be composted.

Can I use olive oil twice?

Olive oil can be used twice for frying or deep frying only if exposed to temperatures of not more than 390°F. While it’s lower than the smoking point of olive oil, too much heat can damage its healthy components.

Also, use olive oil for cooking dry food items only as water causes it to break down.

Can I fry French fries in the same oil as chicken?

deep fry chicken

Frying French fries in the same oil as chicken will make French fries taste better. That’s because chicken fried in the oil will lend a little of its flavor to French fries. However, if the chicken fried in cooking oil is battered or breaded, remove solids before frying French fries in the same oil.

Can I fry chicken and pork in the same oil?

Chicken and pork can be fried in the same oil. The two can be fried in the same oil one after the other. They can also be fried in the same oil at the same time. However, if one is made to have a distinct flavor using herbs, spices or seasonings, cook it last to keep the other from having its taste.

Can I fry chicken and fish in the same oil?

It is possible to fry chicken and fish in the same oil, provided that chicken is cooked in it first. Fish has a distinctive taste and odor. Cooking chicken in oil used for frying fish will cause chicken to have a fishy taste and smell. Never cook chicken and fish in the same oil at the same time.

Can I fry chicken and shrimp in the same oil?

When using the same oil for frying chicken and shrimp, fry chicken first. It’s for a couple of reasons. First, it will save chicken from acquiring the characteristic taste and odor of shrimp. Second, it will make chicken safe to be consumed by anyone who has an allergy to shrimp and other shellfish.

How can I tell if oil should be disposed of?

Before reusing cooking oil, check the color, smell and consistency. If it has turned dark or black, it should be disposed of. Oil should not be reused if it already smells rancid. If it has turned thick and sticky, oil should be replaced. Refrain from reusing cooking oils with low smoke points.

Just Before You Reuse Cooking Oil

It is perfectly fine and safe to reuse cooking oil. As a matter of fact, in many instances, it can be reused up to eight times or even more.

If the oil is used for cooking battered or breaded food items, it can be reused three or four times. But no matter if the food cooked in it is battered or breaded or not, the oil should be strained before storing it.

However, as always, there are exceptions to the rule.

Cooking oils that can be reused several times are those with high smoke points. This means that they do not easily burn and produce smoke when exposed to high temperatures.

On the other hand, cooking oils with low smoke points should not be reused. In fact, many of them are suited for raw applications only, such as for making dressings.

Just because the cooking oil you are using has a high smoke point doesn’t mean that it can be reused to your heart’s content. If it’s already black, rancid and sticky, it should be disposed of.

Photo credit: ©canva.com

Read Also