Leaving Oil In Fryer: Safe Or Not?

Deep-fried food is delicious, but what do you do with the oil once you're done? Can you leave it in the fryer, or do you need to remove and store it elsewhere? The answer depends on several factors. Firstly, the type of oil matters; vegetable oil, for instance, has a high smoke point, making it a better choice for reuse. Secondly, the container matters; an airtight seal is crucial to prevent excess oxygen exposure, which can cause rancidity and an unpleasant odor. Thirdly, the frequency of use matters; oil can be stored in the fryer for a few days to a few weeks, but it's recommended to strain and clean the fryer after each use. Finally, the presence of food particles matters; they can degrade and contaminate the oil, so it's important to filter them out. In summary, while you can leave oil in a deep fryer for a short period, taking the time to store it properly will ensure it remains safe and tasty for future frying adventures.

Straining the oil

Allow the Oil to Cool:

Before you begin straining, it is crucial to let the oil cool down completely. Do not be tempted to start the process while the oil is still hot, as this can be dangerous and may lead to burns. Make sure the oil has reached room temperature.

Prepare Your Straining Setup:

You will need a fine-mesh strainer or sieve and a filter. Place the strainer over a bowl or a large glass measuring cup. You can line the strainer with a filter of your choice. Here are some options:

• Cheesecloth: Double up the cheesecloth and place it inside the strainer. This method may be a bit messy, but it is effective.
• Coffee Filter: A paper coffee filter can be used as a fine filter. It is finer than a strainer alone and will catch more particles.
• Paper Towel: Using a paper towel as a filter is a cheaper alternative to a coffee filter, and it can be placed inside the mesh strainer to support it and prevent tearing.
• Flour Sack Towel: A lint-free, 100% cotton flour sack towel can be used as a filter and washed afterward for reuse.

Slowly Pour the Oil:

Once your setup is ready, slowly pour the cooled oil into the filter. Be careful not to pour the last bit of oil that contains deep-fry debris—the bits of flour or batter that have settled at the bottom of the frying pot. These particles can burn and affect the taste of the oil when reheated.

Store the Strained Oil:

After straining, transfer the oil to a clean, sealed container. You can use a glass jar or even reuse the original oil bottle if you have one. It is recommended to label the container with the date, the type of food the oil was used for, and the number of times it has been used. Store the oil in a cool, dry, and dark place, away from heat sources like the oven, fridge, or microwave.

By following these steps, you can effectively strain your frying oil and extend its lifespan. Remember to pay attention to the oil's appearance, smell, and behavior when reheating. If it becomes dark, cloudy, or musty-smelling, or if it emits smoke or foam, it's time to discard it and start with fresh oil.

Storing the oil in a cool, dry place

Storing oil in a cool, dry place is essential for preserving its quality and safety for reuse. Here are some detailed guidelines and tips for storing oil properly:

Choose the Right Storage Container

Select a container made of glass or ceramic to store the oil. Avoid using plastic containers as they may not be heat-resistant and could potentially leach chemicals into the oil. Ensure the container has a tight-fitting lid to prevent oxidation and maintain freshness.

Strain and Filter the Oil

Before storing, it is crucial to strain the oil to remove any food particles, crumbs, or debris. Use a fine-meshed sieve or strainer lined with cheesecloth to effectively capture even the smallest particles. This step is vital as leftover particles can degrade and contaminate the oil over time.

Store in a Cool, Dark Location

Identify a cool, dry place in your home to store the oil. Avoid storing it near the oven, fridge, or microwave, as these appliances can generate heat. Also, keep the oil away from direct sunlight or heat sources, such as stoves or radiators. A pantry or cabinet away from heat-generating appliances is ideal.

Label the Container

It is a good practice to label the container with the date, the type of oil, and the number of times it has been used. This information will help you track the oil's freshness and determine when it needs to be discarded. Oil can be stored for up to three months if properly filtered and stored in a cool, dark place.

Regularly Inspect the Oil

Before reusing the oil, always inspect it for any signs of contamination. Oil should maintain its clarity and not appear cloudy. If the oil becomes cloudy or develops a rancid odour, it is no longer safe for consumption and should be discarded.

Choose the Right Type of Oil

The type of oil you use also impacts its reusability. Vegetable oil is a popular choice for deep frying due to its high smoke point. Oils with a high smoke point are less likely to break down during the frying process and can be reused multiple times.

Maintain Good Fryer Hygiene

To ensure the oil remains safe for reuse, it is essential to keep your deep fryer clean. Regularly clean the fryer, removing any food particles or residue. A clean fryer helps prevent contamination and extends the oil's lifespan.

By following these guidelines, you can safely store and reuse oil, reducing waste and saving costs. Remember always to handle hot oil with caution and allow it to cool completely before straining and storing.

Reusing the oil

If you want to reuse the oil in your deep fryer, there are a few things you should keep in mind to ensure it remains safe for consumption.

Firstly, it is important to note that the oil will take on the flavour of whatever you fry in it. Therefore, it is recommended to fry similar items in previously-used oil. For example, don't fry cinnamon doughnuts in yesterday's catfish oil, or falafel in yesterday's Korean fried chicken oil.

Additionally, the order in which you fry your food matters. Vegetables tend to have the least impact on the oil, leaving minimal flavour and debris. Breaded items, on the other hand, especially those with a fine coating of flour or cornstarch, tend to leave lots of particles that will continue to cook and burn even as the oil cools, infusing the oil with a bitter flavour. So, it is best to save these items for last and make sure to strain the oil when you're done frying.

After you're finished frying, turn off the heat and allow the oil to cool completely. This is important for safety reasons, as oil burns can be dangerous. Once the oil has cooled, strain it through a fine-meshed sieve lined with cheesecloth to catch any fine matter left behind. While it may be tempting to skip this step, these particles will burn and make the oil taste nasty when reheated.

Next, transfer the strained oil into a clean container, such as a glass jar or the original oil bottle, and store it in a cool, dry place away from heat sources like the oven or microwave.

It is also helpful to label the container with the date, what the oil was used for, and the number of times it has been used. This will help you keep track of how many times the oil has been reused.

Frying oil can generally be reused anywhere from two to eight times, depending on the type of oil, what you're frying, and how well you've strained it. There is no hard and fast rule, but if the oil has become dark or dirty, is smoking before reaching frying temperature or foaming at the top, or has developed a rancid or musty smell, it's time to dispose of it.

Disposing of the oil

It is important to dispose of your frying oil properly. Do not pour it down the sink drain as it can congeal and clump, clogging your pipes and leading to a plumbing disaster.

You can solidify the oil and then throw it away. A product called FryAway will solidify your oil into a block that can be tossed into the trash. Alternatively, you can pour the oil into a sealable disposable container, close it tightly, and throw it away.

Depending on where you live, you may be able to recycle your used oil. Use an online tool such as Earth 911 to search for recycling drop-offs near you, or check with local services.

If you have a campfire, you can pour the oil over corrugated cardboard or paper towels, stack your wood around it, and light the paper towels. You can also use oil in this way to get a charcoal chimney for a charcoal grill started.

Used vegetable oils can be used as an eco-friendly way to get rid of weeds in your garden. Simply add the oil to a reusable spray bottle and spray the weeds until they are coated.

Another option is to mix old oil with oatmeal and put it out for the birds.

Safety concerns

Safety is a key concern when it comes to storing and reusing frying oil, and there are several factors to consider.

Firstly, it is important to prevent the oil from developing harmful free radicals, which are linked to cancer and heart disease. This can occur when oil is exposed to excess oxygen, which happens naturally when food is fried. To minimise this, oil should be cooled completely and stored in an airtight container, in a cool, dry, dark place. It is also important to note that the oil will take on the flavour of whatever is fried in it, so it is best to fry similar items in previously used oil.

Secondly, the oil should be strained after each use to remove any food particles, which can degrade and contaminate the oil over time, leading to possible food poisoning. Fine-mesh sieves or strainers can be used for this, and some people also line the sieve with cheesecloth or kitchen paper to catch fine particles.

Thirdly, the type of oil and the material of the fryer are important factors. Vegetable oil is recommended as it has a high smoke point, and modern deep fryers are often made with an airtight cover. Oil should not be reused if it has reached its smoke point, as this is dangerous.

Finally, oil should not be stored for too long. Generally, used oil can be stored for up to three months if filtered and stored correctly. However, frying oil can be reused anywhere from two to eight times, depending on the oil type, what is being fried, and how well it has been strained. If the oil becomes dark or dirty, smokes before reaching frying temperature, foams at the top, or develops a rancid or musty smell, it should be discarded.

Frequently asked questions