Does Olive Oil Evaporate

In this brief article, we will answer the question, “does olive oil evaporate?”. We will also tell you how long it takes for olive oil to evaporate, what makes oil evaporate, what happens after oil evaporates, and some interesting uses of olive oil.

Does Olive Oil Evaporate?

Yes, olive oil will evaporate at room temperature. However, this evaporation is extremely minute and gradual, and might not even be measurable in a closed environment.  

Olive oil will only vaporize when the oil (in a gaseous state) is in equilibrium with the liquid phase.

How Long Does Olive Oil Take To Evaporate?

Evaporation of liquid can be considered as the movement of molecules from the surface into the vapor phase above it. The layer of air directly above the evaporation surface is known as the boundary layer. The characteristics of this air layer can influence evaporation. In the case of water, the air regulates the evaporation rate. Air is capable of holding a variable amount of water, depending on temperature. At constant temperature, and constant removal of the water vapor from the boundary layer, the evaporation rate of water is constant. Most oils evaporate at an exponential or logarithmic rate with respect to time and the evaporation rate is not boundary regulated, because most of the components of oil evaporate so slowly that molecular diffusion is sufficient to carry the molecules from the surface. Temperature was found to be the most important environmental variable affecting oil evaporation (1). Free fatty acids are the most volatile compounds in oil (2).

Fixed oils such as olive oil are relatively resistant to evaporation and can take months and even years to evaporate completely, leaving behind a sticky varnish.

To better comprehend how long it takes for different oils to evaporate, you must be familiar with the two main categories of oils: volatile oils and fixed oils.

Volatile oils, mainly used in perfumes, are obtained mainly from plants and their petals, leaves, bark, and roots. They are classified as essential oils and usually take several days to weeks to evaporate completely. Also, they leave behind little or no residue. 

On the contrary, fixed oils are classified as cooking oils and are mainly obtained from seeds. They contain a greater amount of fatty acids and glycerin and as mentioned, take months to years to evaporate completely, leaving behind a sticky residue.

What Causes Oil To Evaporate?

The main reason why oils, or liquids in general, evaporate is the presence of active (kinetic) energy. Oil surface contacting the air and air conditions such as moisture and wind influences the evaporation rate and especially temperature (1).

You must be familiar with the basic fact that everything is composed of atoms, and in liquids, atoms are in continuous motion. How fast a liquid evaporates depends on the dispersion rates of atoms within it. Simply put, particles that move more rapidly are more probable to leave the fluid in the form of gas. 

Why Does Oil Evaporate Slower Than Water?

The reason oils take longer to evaporate than lighter liquids, such as water, is their weight/mass and a larger number of bonds between atoms.

Contrary to lighter liquids, oils are composed of larger atoms with loads of carbon bonds. These stronger intermolecular forces make it relatively difficult to break an oil molecule, thus it evaporates very slowly. Besides, water has a homogeneous composition, while oils are heterogeneous and contain different amounts of shorter and longer fatty acid chains. The smaller molecules evaporate first and that causes the longer molecules to concentrate. These are more difficult to vaporize. Because of this, the evaporation rate of oil is not linear, but rather exponential or logarithmic (1). 

What Happens After Olive Oil Evaporates?

As discussed, olive oil is a fixed oil, hence it leaves behind a buildup after it evaporates, which usually ends up staining almost everything it comes in contact with. 

You might be familiar with these stains remaining on pots, containers, or skillets in your home or kitchen. 

Also, oil generally tends to leave stains on utensils when the rate of dissipation is increased due to excess heat.

What is The Smoking Temperature of Olive Oil?

The smoke point is defined as the temperature at which a visible and continuous bluish smoke appears. At this point sufficient volatile compounds, such as free fatty acids and short chain oxidation products are emerging and evaporating from the oil. The smoke point of an oil generally increases as the free fatty content decreases, and the degree of refinement increases (2). 

The smoking temperature of olive oil is 190 degrees Celsius (375 degrees Fahrenheit). 

Before oil boils, it goes through a ‘smoking’ phase. This is a temperature that is exclusive for different oils and sometimes causes food to develop a burnt flavor. Boiling points are determined by how pure the oil is. The standard procedure used to establish the smoke point relies heavily on the ability of the worker to visually determine the point at which the oil begins to smoke. This means that there can be analyst subjectivity when using this test procedure. Studies have shown that the smoke point rises when using a bigger container or a larger volume of oil in the presence of air. As a result, when cooking in a kitchen, smoke point temperatures could be greater than the ones that have been reported in the literature (2).

Here are the smoking points of some common oils:

• Canola oil: 205 degrees Celsius (401 degrees Fahrenheit)
• Sunflower oil: 225 degrees Celsius (437 degrees Fahrenheit)
• Peanut oil: 250 degrees Celsius (437 degrees Fahrenheit
• Corn oil: 230 degrees Celsius (446 degrees Fahrenheit)
• Palm oil: 235 degrees Celcius (455 degrees Fahrenheit)
• Soybean oil: 257 degrees Celsius (495 degrees Fahrenheit)
• Cotonseed oil: 230 degrees Celsius (446 degrees Fahrenheit)
• Sesame oil: 116 degrees Celsius (240 degrees Fahrenheit)
• Ricebran oil: 213 degrees Celsius (415 degrees Fahrenheit)

What Is Olive Oil Used For?

As a cooking medium olive oil has many functions, such as transferring heat from the heat source to the food, acting as a lubricant to prevent food from sticking to the cooking surface, adding flavor, crust and creating a more visually appealing look to the food. It is an extremely healthy oil to use for all types of cooking and there is a lot of existing and emerging research related to the health benefits due to high levels of antioxidants (some of which are unique to olive oil) and the ability of the oil to enhance the health attributes of some ingredients once cooked (2).

Other than cooking, people also use olive oil for medicinal purposes, particularly those suffering from chronic conditions such as diabetes, heart disease, and high blood pressure (3). 

People also use olive oil for the following conditions:

• lowering high cholesterol
• symptomatic treatment of cancer
• improve memory and cognitive skills
• treat migraine
• lowering the risk of obesity

Remember: these are simple home remedies and there isn’t any conclusive scientific evidence to support the efficacy of these uses. ALWAYS consult a health professional before adding anything to your diet, especially if you’re on long-term medication. 

Conclusion

In this brief article, we answered the question, “does olive oil evaporate?”. We also told you how long it takes for olive oil to evaporate, what makes oil evaporate, what happens after oil evaporates, and some interesting uses of olive oil.

If you have any more questions or comments please let us know.

References

1.  Fingas, Merv. The evaporation of oil spills: Prediction of equations using distillation data. Spill Sci Technol Bull, 1996, 3, 191-192.
2. de Alzaa, Ana Florencia, Claudia Guillaume, and Leandro Ravetti. Cooking with Extra Virgin Olive Oil. 2021.  
3. Harwood, John L., and Parveen Yaqoob. Nutritional and health aspects of olive oil. Euro J Lipid Sci Technol, 2002, 104, 685-697.