How Long Does Oil Last in a Deep Fryer? [Honest Answer]

Many people look for the answer in Google to a few questions related to deep frying.

How Long Does Oil Last in a Deep Fryer?

What to do with the used oil?

Are there any ways to increase the lifespan of the cooking oil?

These are common questions since nobody wants to throw away expensive oils after using them for cooking a single chicken fry batch.

At this point, both good and bad news is there.

Good news is

  • Throwing away of used oil is unnecessary. You can reuse them several times.
  • With a few signs, you can quickly know when you need to replace the oil. And following some simple methods, the lifespan of oil can be increased.

Bad News is

  • A strict answer is unavailable to the question of how many times I can reuse an oil. Disbelieve in any source that gives a strong response to the number that can reuse your oil.

How Long Can You Keep Cooking Oil in a Deep Fryer?

How Long Does Oil Last in a Deep Fryer

When you find the below signs in your cooking oil while deep frying, ensure changing it

  • Foam on the oil surface when it is hot
  • Odor or smell of fish (even if you don’t deep fry fish)
  • If the oil creates a lot of smoke than other times
  • Becomes much darker

As stated earlier, there is no specific number, but you can follow the below guideline. However, it is always advisable to use your senses before changing or keeping oil in a deep fryer.

Important Note: Oil last longer in a deep fryer than oil used for frying in a skillet

Food TypeApproximate Number of Uses
All types of non-breaded items and French fry6 – 8 times
Crumbly foods and breaded3 – 4 times
Fish2 – 3 times
Vegetables6 – 8 times
Meat3 – 4 times
Poultry3 – 4 times

Also Read: Can You Deep Fry with Canola Oil? Let’s explore

What Factors Can Ruin the Oil?

A few factors play a vital point in boosting up the lifespan of oil in a deep fryer.

Frying Vessel Type

The unfortunate thing is, home oil gets ruined faster than restaurant oil. It happens because of the heating arrangements. Heating arrangement varies in home and restaurant.

You will find dedicated deep fryers at a restaurant, and the heating elements are raised above the oil chamber’s bottom. As a result, at the very bottom, under the heating elements, a pocket of comparatively cool oil gets created. Small bits of foods that fall off with the fried foods, they sink to the bottom of the chamber. The heating elements stay in the top areas of these themes.

On the other side, at home, we fry food in a pot or wok. Fallen food particles take their position at the bottom part of the pan and direct contact to heat and start burning. These particles supply their flavor to oil and speed up oil’s breakdown.

Unluckily, you can’t avoid this problem unless you buy a deep fryer used for deep frying only.

Coating Type

The general thumb rule is; oil will break down faster if the oil gets introduced to more particulate matter.

Onion rings or French fries will leave a small number of residues in the oil after frying. While crumbs will be left behind in the oil after frying chicken cutlets. On the other hand, your cooking oil will get introduced to various particles if you fry fish sandwiches.  

So, cooking oil will last longer when you fry battered foods. And with flour-dredged foods, the oil will break down after using the oil 3 – 4 times.

Oil Type

Every oil type doesn’t contain the same level of saturated and unsaturated fats. The same statement is valid for the other components of the oil too. Due to this, the frying process and temperature level get affected. 

Generally, a higher temperature is necessary to heat different refined oils like vegetables, canola, or peanuts compared to raw-oils such as sesame oils or extra-virgin olive oil. 

But it doesn’t mean you can’t deep fry with raw oils; it means, when you use raw oils for deep fry, the oil will break down faster than refined oils.

Also Read: Can You Use Vegetable Oil in a Deep Fryer: The Ultimate Guide

Can I Clean Oil?

Well, this is another one of the most common questions of newcomers or home chef. 

Pieces of different sized debris and floaters are common in oil after deep frying any food item. How to skim them off? The easiest way is using a skimmer.

After skimming off that debris, take a fine mesh strain, and pour the oil through it to store into a pot or container. If you fried floor-dredged foods, at the bottom of the deep fryer, you would find a large amount of flour. Don’t pour them into the pot or container; discard them separately. Ensure proper tightening or covering of the pot so that dust or dirt can’t fall into it and let the oil cool.

You are almost done with the process of cleaning and storing the oil. Take a funnel and pour the oil into the original container. Seal the container properly and ensure storing it in a dry and cool place.

How to Increase Oil’s Lifespan?

  1. Thermostat Using: Oil breaks down quickly if it is overheated. Similarly, when you add food into the oil before it is sufficiently heated, the food’s frying time will increase. This way, debris and other particles fall off into the oil at a higher rate, shortening the oil’s lifespan. So, it would be best if you check the oil temperature using a thermostat.
  2. Ensure Cleaning the Oil When Frying: At the time of frying foods, keeping a mesh strainer beside the pot will be a wise decision. Thus, you can discard any dust or debris that has fallen off in the oil.
  3. Fry Battered Foods: Breaded foods release more debris and impurities to oil than battered foods. It means frying battered foods in a deep fryer is an excellent decision to increase your cooking oil lifespan.

With all the above tips, your cooking oil can still ruin quickly because many factors play a vital role in this point. The best tip is, use your sense when to reuse and clean the oil.

If the oil becomes foamy or smells bad, simply discard it and use fresh oil to fry your foods. Remember, using bad oil is harmful to human health.

Also Read: Can You Deep Fry an Egg? A Complete Frying Guide

Frequently Asked Question

Wrapping Up

Did you get enough information reading this article on how long does oil last in a deep fryer? Your sense is the best solution maker before using, reusing, or cleaning the oil.

What is your favorite food to deep fry? Feel free to comment below.