Why Is My Deep Fat Fryer Foaming?

Why Is My Deep Fat Fryer FoamingA deep fat fryer is among the most commonly used equipment for commercial deep frying. This is because they are more efficient when used on large-scale compared to other types of deep fryers.

When in use, you may have discovered that the deep fat fryer foams a lot and you probably began to doubt the quality of the equipment or the oil that you were using.

In this article, we are going to cover the reasons behind foaming deep fat fryers. Deep fat fryers foam mainly because of the following reasons;

  • Moist ingredients
  • Starch
  • Dirty oil
  • High temperatures

Moist Ingredients

This is the most common cause of foam in deep fat fryers. When you are deep frying moist ingredients, the water on the surface of whatever is being fried gets displaced and it is released into the oil. From the knowledge of chemistry about mixtures, we know that oil is not soluble in water. Since the water and oil do not mix, the water gathers in droplets and then it moves to the surface of the oil. The insolubility of oil the water is what causes the foaming effect in the deep fat fryer. There is only one way that you can prevent this from taking place and it is by removing as much moisture as possible from the ingredients that you intend to deep fry.


This is the other cause of foaming deep fat fryers. Starch breaks down in the frying process and as a result, it releases a substantial amount of foam. Although it is annoying, this is an unavoidable occurrence unless if you can find an alternative way of frying those meals that have a high starch content. It is also worth noting that using a high-quality type of oil can help prevent this problem or if not, it is going to reduce the impact of the foaming.

Dirty oil

If you reuse your oil for a long time, it is obvious that some small burnt food particles will accumulate at the bottom of the deep fryer. Sometimes the dirt is just suspended in the oil and whenever you use it to fry, a lot of foam is produced. It is advisable to regularly replace the oil after you have used it for two or three times. This will prevent dirt from accumulating at the bottom of the deep fryer. Alternatively, you can also try a different type of oil that does not get dirty upon reusing. Vegetable oil or olive oil is a great option if you want to avoid this kind of effect from occurring.

High Temperatures

 Sometimes the oil in a deep fryer foams up due to high temperatures and this seems to a problem that is fairly easy to prevent. More often than not, high-quality oils have a tendency to withstand high temperatures without foaming. As such, you can opt for the high-quality oil for use in a deep fat fryer. Also, it is worth noting that the more you reuse your oil, the more incapable it becomes to withstand high temperatures without foaming. Again olive oil and pure vegetable oil are better options especially if you are frying meals that require high temperatures.


In conclusion, the main causes of the foaming effect in a deep fat fryer are high temperatures, starchy foods, moist ingredients and dirt in the oil. Each of these causes is highly preventable. If you try all the prevention methods mentioned above without any success, then you probably should check either the condition of the deep fat fryer or maybe you could be overloading the fryer beyond its food capacity. 

About the Author Harry Thompson

Gaining a BSc Honours in building/ property maintenance at the University of Portsmouth Harry went into the field of renovating properties. Along the journey, he has developed a wide variety of home & garden DIY skills such as installing new kitchens and landscaping gardens.