Deep Frying With Olive Oil: How Long Does It Last?

Olive oil is a healthy choice for deep frying, contrary to the popular misconception that it is unsuitable for high-temperature cooking. The USDA recommends olive oil for deep frying, citing its high smoke point and health benefits. The smoke point of olive oil ranges from 350°F to 468°F, which is higher than that of butter. This means that olive oil can be safely used for deep frying without reaching its smoke point, where it breaks down and forms unhealthy compounds. While extra virgin olive oil can be used for deep frying, cheaper options like regular and light olive oil are more suitable due to their higher smoke points and neutral flavours.

• Odor or smell of fish
• If the oil creates a lot of smoke | | Factors that can ruin the oil | - The oil will break down faster if it is overheated
• Onion rings or French fries will leave a small number of residues in the oil
• Crumbs will be left behind in the oil after frying chicken cutlets | | How to increase the lifespan of the oil? | - Use a thermostat to check the oil temperature
• Clean the oil while frying using a mesh strainer
• Fry battered foods instead of breaded foods |

Olive oil's smoke point

The smoke point of an oil is the temperature at which it starts to smoke, indicating that it is breaking down and potentially forming harmful compounds. The smoke point of olive oil varies depending on the type and quality. Extra virgin olive oil has a smoke point ranging from 350°F to 410°F, while regular olive oil and light-tasting olive oil have a higher smoke point, ranging from 390°F to 470°F.

Despite its reputation for having a low smoke point, olive oil is suitable for deep frying. Deep frying typically requires temperatures of around 350°F to 375°F, which is well within the smoke point range for all types of olive oil. In fact, the USDA includes olive oil on its list of "high smoke-point" oils, recommending it for deep frying.

The stability of an oil is more important than its smoke point when it comes to cooking. Olive oil is rich in oleic acid and contains minor compounds that make it very stable. Extra virgin olive oil, in particular, is the most stable cooking oil due to its high levels of polyphenols and antioxidants, which prevent the breakdown of the oil and the formation of free radicals.

A study published in Food Chemistry compared the oxidation and free radical formation of peanut oil and extra virgin olive oil when heated. The researchers found that extra virgin olive oil was more resistant to oxidation than peanut oil, and both oils created similar amounts of free radicals. This indicates that olive oil can withstand higher temperatures without breaking down or forming harmful compounds to the same extent as other oils.

In summary, olive oil has a high enough smoke point for home cooking, and its stability makes it a safe choice for deep frying.

Reusing olive oil

How to Reuse Olive Oil:

Firstly, it is important to note that olive oil can be reused several times, but it should be filtered correctly between each use. Filtering the oil will prevent its smoke point from decreasing dramatically. The smoke point for filtered extra virgin olive oil is 207 °C (405 ºF), which is well above the deep-frying temperature, which rarely exceeds 190 °C (374 ºF).

To filter the oil, let it cool and then pass it through a couple of layers of cheesecloth, a fine-meshed sieve, a paper coffee filter, or even paper towels. The aim is to remove any leftover fried bits, as these particles can burn when reusing the oil.

Once the oil has been filtered, store it in an appropriately-sized container, preferably a dark-coloured bottle, a glass jar, or an opaque stainless steel container. Ensure the container is tightly capped and store it in a cool, dark place, like a pantry. Do not store the oil near the stove or in the light, as heat and light will accelerate the oxidation of the oil.

It is also a good idea to label the oil with the date and what you fried in it. Cooking oils retain some of the flavours of the food, so you want to avoid frying doughnuts in oil used for fish, for example.

There is no strict answer to how many times you can reuse olive oil, but it is generally accepted that you can reuse it up to 5 times. It is important to use your senses when deciding if the oil needs to be replaced. If the oil becomes foamy, smells bad, or changes colour or viscosity, it is time to discard it.

Other Tips for Reusing Olive Oil:

• Only reuse the oil for cooking. Use fresh oil for dressings and marinades.
• Plan ahead by frying neutral-tasting foods in the oil when it is fresh and stronger-flavoured foods when reusing it.
• Avoid getting water into your frying oil, as this will prevent the food from becoming crisp.
• Check the oil temperature with a thermometer to ensure it is sufficiently heated before adding food.
• Fry battered foods, as breaded foods release more debris and impurities into the oil.

Increasing olive oil's lifespan

Olive oil is a great choice for deep frying. It has a high smoke point and is resistant to heat. However, there are some things to keep in mind to increase the lifespan of olive oil in a deep fryer.

Firstly, it is important to note that the type of oil and the temperature used for deep frying can impact its lifespan. Oils with higher levels of saturated and unsaturated fats, such as olive oil, have a higher smoke point and are more stable at high temperatures. Therefore, choosing an olive oil with a higher smoke point can increase its lifespan.

Secondly, it is crucial to maintain the proper temperature when deep frying. Overheating the oil can cause it to break down quickly. Using a thermostat to monitor the oil temperature is recommended. Additionally, ensuring that the oil is sufficiently heated before adding food will reduce the frying time and minimise the amount of debris and particles that fall into the oil, extending the oil's lifespan.

Thirdly, the type of food being fried can also affect the lifespan of the oil. Battered foods tend to release fewer debris and impurities into the oil compared to breaded foods. Therefore, frying battered foods can help increase the lifespan of the cooking oil.

Additionally, regular cleaning and filtering of the oil can prolong its lifespan. Using a mesh strainer to remove any dust or debris that falls into the oil during frying is a good practice. After frying, the oil can be filtered through a cheesecloth or paper coffee filter to remove food particles before storing it in a sealed container.

Lastly, it is important to use your senses when deciding to reuse or discard the oil. If the oil becomes foamy, smells bad, or develops an odd odour, it is best to discard it and use fresh oil.

By following these tips, you can increase the lifespan of olive oil in a deep fryer and enjoy delicious fried foods without worrying about oil breakdown or degradation.

Olive oil's health benefits

Olive oil is one of the healthiest oils for deep frying. It is resistant to heat because it is high in monounsaturated fatty acids, which are relatively stable. In one study, olive oil was used in a deep fryer for over 24 hours before it oxidized excessively. This makes it a great choice for deep frying.

Rich in Healthy Fats

Olive oil is rich in healthy monounsaturated fats. Olive oil's predominant fatty acid is oleic acid, a monounsaturated fat that makes up 71% of its total oil content. Monounsaturated fats are quite resistant to high heat, making extra virgin olive oil a healthy choice for cooking.

High in Antioxidants

Extra virgin olive oil contains modest amounts of vitamins E and K. However, it is also loaded with powerful antioxidants that may help reduce your risk of chronic diseases that affect your cardiovascular and central nervous systems. These antioxidants may also fight inflammation and help protect blood cholesterol from oxidation, thereby lowering your risk of heart disease.

Anti-inflammatory Properties

Extra virgin olive oil may help reduce inflammation, which may be one of its main health benefits. The antioxidants mediate the main anti-inflammatory effects. Key among them is oleocanthal, which has been shown to work similarly to ibuprofen. Research also suggests that oleic acid, the main fatty acid in olive oil, can reduce levels of certain inflammatory markers, such as C-reactive protein (CRP).

May Help Prevent Strokes

The relationship between olive oil and stroke risk has been studied extensively, but the results are mixed. A 2014 review of studies on 841,000 people found that olive oil was the only source of monounsaturated fat associated with a reduced risk of stroke and heart disease. However, a 2020 meta-analysis found no significant link between olive oil intake and stroke risk.

Protective Against Heart Disease

Extra virgin olive oil is one of the key ingredients in the Mediterranean diet, which has been shown to significantly reduce the risk of heart disease. A 2018 review suggests it may help lower inflammation and increase HDL ("good") cholesterol. Olive oil has also been shown to lower blood pressure, a strong risk factor for heart disease and premature death.

Not Associated with Weight Gain and Obesity

Numerous studies have linked the Mediterranean diet, which is rich in olive oil, with favourable effects on body weight. A 2018 review also found that diets high in olive oil helped promote weight loss more than diets low in olive oil.

May Fight Alzheimer's Disease

A 2024 review found that olive oil may reduce the risk of developing Alzheimer's disease and cognitive impairment by reducing beta-amyloid plaques, neuroinflammation, and oxidative stress.

May Reduce Type 2 Diabetes Risk

A 2019 study found that people with prediabetes who consumed 55 ml of oleanolic acid-enriched olive oil each day were 55% less likely to develop diabetes than participants in the control group. A 2017 meta-analysis also found that olive oil supplementation significantly helped reduce blood sugar levels and fasting plasma glucose in people with type 2 diabetes.

May Have Anticancer Properties

A large 2022 meta-analysis found that people who consumed the highest amount of olive oil were 31% less likely to develop cancer. This may be due to the oil's antioxidants, which may help reduce oxidative damage caused by free radicals, a leading driver of cancer.

May Help Treat Rheumatoid Arthritis

A 2023 study found that olive oil was linked to lower inflammatory markers and disease severity in people with rheumatoid arthritis, especially for more severe disease activity. The researchers also found that olive oil helped decrease CRP levels, which may play a role in inflammation and disease progression.

Has Antibacterial Properties

A 2022 animal study found that extra virgin olive oil may help fight certain strains of Helicobacter pylori, a bacterium that can cause stomach ulcers and stomach cancer.

Olive oil's flavour

Olive oil is a great choice for deep frying. It's been used for this purpose in the Mediterranean for centuries. Olive oils have different flavours and different smoke points, depending on the extraction process.

The smoke point of an oil is the high temperature at which it starts to break down and form free radicals, which are unhealthy compounds that impart a bitter or rancid taste to fried foods. The smoke point of olive oil ranges from 350° to 410° F, depending on the type of olive oil. The smoke point given by the USDA of 410 °F is for extra virgin olive oil, while olive oil and light-tasting olive oil have a higher smoke point of up to 468 °F.

The flavour of olive oil degrades when heated for long periods, so it's best to cook quickly when frying with extra virgin olive oil. The flavours of olive oil can also be affected by the food cooked in it, so it's important to be mindful of where you use it. For example, don't use oil from frying onion rings to make something sweet, like churros.

Regular olive oil is a good choice for deep frying as it has a higher smoke point than extra virgin olive oil and virgin olive oil. It is made of a blend of refined olive oil and virgin olive oil (15% to 25%). The refined portion is treated with heat and chemicals to remove any defects in flavour, which also raises the smoke point to about 390° - 470° F. However, this process does remove some of the healthy bioactive compounds found in extra virgin olive oil and virgin olive oil.

Light olive oil is another good option for deep frying. It is a combination of refined olive oil and virgin olive oil, with only 5% to 10% virgin oil. Without the tiny olive oil solids, this olive oil has a high smoke point and a very neutral flavour. However, it also has fewer health benefits than extra virgin olive oil, as many of the antioxidants are missing.

While it is possible to deep fry with extra virgin olive oil, it is not recommended due to its high quality and nuanced flavours and aromas. Deep frying with extra virgin olive oil is considered a waste as the flavours and aromas of the oil degrade when heated for a long period of time.

Frequently asked questions