How To Tell If Oil Is Hot Enough To Fry? (6 Proven Methods)

Deep frying or shallow frying food might not be the healthiest option but it’s one of the quickest and crispiest ways to cook food. However, to get that delicious and irresistible crispy, golden-brown crust, the oil needs to be perfectly hot, too hot, and food will burn outside before cooed inside, and not hot enough and food will be soggy and greasy.

So, how to tell if oil is hot enough to fry?

In this article, I’ll discuss 6 safe and effective ways to determine whether the oil is hot enough for frying or not.

1. Use Food Thermometer

checking the oil temperature with a food thermometer

Using a food thermometer is the most effective way to check if your cooking oil is at the right temperature. You only need to clip the thermometer to the side of the pan or pot containing oil. Ensure that the thermometer’s bottom is submerged in oil but isn’t touching the bottom.

The thermometer will provide you with an accurate temperature reading within 1 to 2 minutes. 

The temperature of the oil that you want to use to deep fry should be between 350 to 375°F (176 to 190°C). Whereas 320 to 375°F (160 to 190°C) will be enough for shallow frying and 350°F (177°C) for pan-frying needs.

Check Out Also: Deep Frying At Home Oil Temperature And Cooking Times Chart.

2. Use a Batter Or Dough

dropping a tiny piece of batter or dough into the oil

If you don’t have a thermometer, you can use dough or batter to check the oil temperature. This method comes in handy when you’re frying battered food or donuts.

Just drop a small piece of dough or batter into the oil. If it sinks to the bottom and rises gradually without sticking, your oil is ready for frying. But if it sticks to the bottom, the oil needs more time to heat properly.

While you can use this method for shallow frying, it’s most effective while deep frying. That’s because it shows that your oil temperature is higher than 375°F (190°C).

3. Use Popcorn Or Kernel

testing the oil temperature with a popcorn kernel

While using popcorn or kernel is an effective way to check the oil temperature, it can be a bit dangerous. Therefore, you should wear safety gloves while using this method to protect your hands from hot oil splashes.

If the oil is in the right temperature range of 350 to 375°F (177 to 190°C), the popcorn kernel will pop immediately. Keep in mind that there is always that one odd kernel that does not pop, so I recommend you use at least three kernels. You can use this method also when you want to shallow or pan fry.

4. Use Onion

deep fry oil temp check with onion

Using onion is a great way to test the temperature of oil, especially while shallow or pan-frying. Drop a small piece of onion in the oil and observe how it reacts. If there are no bubbles and it takes more than 10 seconds for the onion piece to turn brown around the edges, the oil isn’t hot enough.

However, if the piece of onion starts to sizzle immediately, you can start the frying process. It indicates that your oil temperature is above 360°F (182°C), which means it’s ready for deep and shallow frying. You’ll need to reduce the temperature if the onion piece starts to turn brown immediately.

5. Use a Wooden Spoon

You see bubbles form around the wooden spoon

The above method is great if you are making onion rings but if you don’t want the taste of onion in doughnuts, churros or Ramnut consider using a wooden chopstick or a wooden spoon.

Dip a wooden chopstick or a wooden spoon into the heated oil. If many small bubbles form vigorously around the stick/spoon, your oil is hot enough to fry. It shows that the oil temperature is higher than 375°F (190°C). 

It’s an effective and tested way to determine whether your oil is hot enough for deep frying or not. The oil will need more time to heat if you notice very few or no bubbles at all.

6. Use a Piece Of Bread

dropping a cube of bread into the hot oil and time how long it takes to turn golden brown

Dropping a small piece of bread into heated oil is another effective method that professional chefs use. Use a one-inch cube piece of fresh bread (not refrigerated). You should see a lot of small bubbles forming vigorously around the bread piece Count the seconds how long it will take the piece of bread to turn golden brown.

If the bread will turn golden brown in: 

  • 25-30 seconds then the oil temperature is about 320°F (160°C)
  • 20 seconds – 338°F (170°C)
  • 15 seconds at 356°F (180°C)
  • 10 seconds at 375°F (190°C)

If the bread piece takes more time and you only see very few bubbles, the oil is not close to the correct temperature yet.

Why Is It Important To Check Oil Temperature Before Frying?

smoking food in hot oil

It’s important to check oil temperature because it allows you to determine whether the oil is ready for frying or not. If the oil is not hot enough, the food that you want to fry will absorb more oil and will be greasy and soggy and it won’t have a golden crispy crust.

On the other hand, if the oil is hotter than it’s supposed to be, it’ll burn the outer layer of the food and the inside will remain raw. Therefore, oil temperature really matters, and checking it allows you to adjust the temperature for the best frying results.

Tips For Safe And Effective Deep Frying

using a deep frying basket

Checking and adjusting the oil temperature is the first part of the frying process. Keep the following tips in mind to fry food safely and efficiently.

  • Never overcrowd your deep fryer as it will decrease the oil temperature significantly, especially if you are frying frozen foods. As a result, you’ll end up with oily and less crispy food. Always fry your food in small batches to achieve the best results.
  • Always pat dry your food before frying it. Water and hot oil react badly and create a lot of hot splashes. If the oil is extremely hot, the addition of water can even start a fire. So, always try to make sure the food that you planning to fry is as dry as possible, except battered food.
  • Drain the fried food right after taking it out from the pan. If you directly place it on the plate, it’ll become mushy and soggy. You can use a deep fryer basket, tongs, or a slotted spoon to drain the excess grease off the fried food.
  • Place a paper towel on the plate before you add food to it. It’ll help to soak up the excess grease from the food.
  • If the oil starts to smoke, reduce the temperature or take the pan off the heat immediately. Smoke can add a bad and burnt taste to your fried food.
  • Also, smoking can be an indication that the oil should be changed or cleaned.
  • Turn the heat off once you are done frying. Leaving oil on the heat for too long will affect its quality.
  • If the hot oil catches fire, turn off the heat immediately. Never pour water into the oil in such a scenario as it can make the situation worse. Pour a large amount of salt or baking soda into the oil and cover with the lid to smother the flames.


Check out the video below for the best oil for deep frying at home.

What Is The Best Oil Temperature For Frying?

If you’re deep-frying you need to make sure that the oil temperature is between 350°F and 475°F (176°C and 190°C) before you add food to it. Whereas the ideal oil temperature for pan-frying is 350°F (177°C). Use the medium-high temperature settings to heat up the oil.

How Long Does It Take To Heat Oil For Frying?

The commercial deep fryer can heat up from 10 to 35 minutes. How fast the oil will heat up depends on the fryer’s type, size, and amount of oil used. Heating up 1 liter or 33 ounces of oil in the saucepan on the stovetop to the correct temperature will take about 5-7 minutes. 

How To Control Oil Temperature When Frying?

There are a few different ways to control the temperature of the oil when frying. One way is to use a deep fryer, which will maintain a consistent temperature. Another way is to use a thermometer to measure the temperature of the oil, and then adjust the heat accordingly. It is also important to make sure that the food is not overcrowded in the pan, as this will lower the temperature of the oil.

Read Also: Does An Air Fryer Use Oil? (Yes, But Here Is What You Need To Know!)

In Summary

The safest and most effective way to check the temperature of oil for frying is to use a food thermometer. If you don’t have a food thermometer, test the oil temperature with a piece of food or use the wooden spoon as described above. Stay safe and always handle hot oil with extreme caution.

About Jen Evansy

Nutritionist, researcher, avid home cook, and writer interested in everything nutrition and food-related. Striving to inform, encourage, and inspire all the readers to make healthy and informed choices when it comes to cooking, food, diet, and nutrition.