Why does oil foam when frying?

  • By: Emma
  • Date: May 19, 2022
  • Time to read: 5 min.

Table of Contents

Why does oil foam when frying?

Have you ever noticed that it sometimes starts to foam when cooking with oil? If this is something new for you, don’t worry! This blog post will explain the science behind why oil foams.

There are a few reasons why oil can start to bubble up in your pan. The most common cause of foaming is adding water or another ingredient into the pan while cooking. When these liquids are mixed in, they break down some of the proteins on the surface of the oil and create bubbles that rise through the frying food. These bubbles then hit other bubbles and form larger ones- making an even bigger mess!  

But this is not the only reason why does oil foams while frying. There are many more reasons behind this phenomenon. If you want to know, read on.

9 Factors that cause oil to foam while frying

Numerous factors cause oil to foam while frying. This blog post has the ten most common causes of oil foaming.

Excessive heat

Another reason for this bubbling may be that there’s too much heat. This happens when you have a stove that’s too hot or cooking on an electric stovetop at high temperatures. Once again, this will cause some of the proteins to break down and create bubbles in the oil.

Also, if you don’t lower the temperature and heat the oil, it’ll start foaming. For instance, some dishes require multiple batches before all the food is ready to be taken out of the pan. It is common to have high heat for the first batch or two, then lower it for the last few.

Thus, If you don’t lower the temperature, there may be some bubbling in the oil.

Heat from another source

Like having excessive heat on your stove, there are times when the heat for the frying oil is coming from somewhere else- like fire! If you’re using wood or natural gas while cooking, some of it could be transferred onto your fryer, which would then cause bubbling in the oil.

Oil temperature above smoke point

When frying with oil, it mustn’t go over its smoke point because it will damage it more than you want. This is why it is so important to know the smoke point of the oil you’re using.

Oil temperature below smoke point

If your oil isn’t hot enough, you could be dealing with bubbling too. In other words, it needs to be heated up before adding food into the pan for frying. If it isn’t hot enough, you may notice the food starting to foam.

Wrong type of oil

Make sure you are using the right kind of oil for frying! Some oils have lower smoke points than others, so it is essential that you know which one is best for your pan.

An excellent way to tell which operating temperature oil can handle before smoking is to look at its color. If it’s clear or light, then the oil has a high smoke point, which should be okay at high temperatures!

Temperature drop

Just like having your oil too hot can cause things to foam, if you have it turned off right before adding the food into the pan- this will also cause oil to start bubbling. If you fry your food too quickly after turning the oil off, this will also cause bubbles.

Oil contact with another liquid

As mentioned before, water can cause your oil to foam up if you put it into a pan where food is cooking. The same goes for other liquids like wine or beer.

Oil contact with metal

When you cook, the oil is coming into contact with the metal of your pan, which can cause it to foam up because of all the friction and scraping that’s going on.

Oil degradation

Yes, you read it right. Oil contamination or degradation can cause bubbles and foam in oil. When oils are exposed to oxygen, it starts becoming rancid. This is because the oil reacts with the oxygen to oxidize itself.

Oxidation occurs when you cook using oil that’s old or even when you don’t correctly clean/season your pan before cooking with it again- which is why you should always thoroughly wipe out your pans before reusing them.

The problem with oxidation is that the oil becomes less stable and therefore more prone to breaking down into foam or bubbling when it comes in contact with heat.

Most commonly asked question about oil foaming while frying

How should I keep oil fresh prevent foaming?

To avoid bubbling in the oil, make sure you are frying within the first week or two of buying it. Some people claim that you can use salt to purify your oil if it is old for frying, but others believe this will only slow down oxidation.

The best way to keep your cooking oil fresh and stable is by storing it in temperatures that are lower than room temperature and out of direct sunlight. If you need to, using a container with a lid would be the safest bet as long as you remember to put it back when you’re done frying.

Do I need to worry if the oil foams while frying?

Absolutely yes. You should pay attention to bubbles in your cooking oil because it means that the oil has broken down and is no longer stable.

If this happens, there’s a possibility that the food will start to absorb the flavor of the rancid oil- which is why it’s always best to use fresh oils for frying instead.

Final Thoughts

In summary, oil foaming can be caused by high temperatures, water drops in oil, the wrong type of oil, or oil contamination.

So know you know what causes oil foaming while frying. Next time you are frying, use the correct oil temperature, don’t put the food into the pan too early after turning off the oil.

Just remember these tips so that you can avoid oil foaming during frying. Good luck!

Can you use a frying pan on a gas grill?

Previous Post

Can you use a frying pan on a gas grill?

Next Post

Will plastic melt in frying oil?

Will plastic melt in frying oil?