Fryer Oil: How Long Does It Last?

Frying oil is a staple in many kitchens, but how long does it last? The answer depends on several factors, such as the type of oil, the material of the fryer, and the food being fried. In general, frying oil can be stored for up to three months if filtered and stored in a cool, dark place. When stored in a deep fryer, oil can be reused for a few days to a few weeks. However, it is recommended to strain and clean the fryer after each use and replace the oil after eight to ten uses.

To prolong the life of frying oil, it is important to prevent contamination and degradation. Oil should be stored in an airtight container, away from heat, light, and humidity. Additionally, food particles and debris should be removed from the oil after each use. By following these practices, cooks can safely reuse frying oil multiple times, reducing waste and preserving flavour.

How to store fryer oil

Storing your fryer oil correctly is essential to prolonging its lifespan and ensuring it's safe for consumption. Here's a detailed guide on how to store your fryer oil:

Cool the Oil:

Allow the oil to cool down to room temperature after turning off the heat. Frying oil typically has a temperature of 160-180°C when in use, so be patient and let it cool before proceeding.

Filter the Oil:

Once the oil has cooled, it's time to filter it to remove any food particles or debris. Use a skimmer to skim off large pieces of debris floating in the oil. Then, pour the oil through a fine-mesh strainer, cheesecloth, or sieve into a clean container. This step is crucial to prevent impurities from contaminating the oil during storage.

Store in a Suitable Container:

Choose a glass or ceramic container with a tight-fitting lid for storing the oil. Make sure the container is clean and dry before pouring in the strained oil. Seal the container tightly to prevent air exposure, which can cause oxidation and rancidity.

Label and Store in a Cool, Dark Place:

Label the container with the date to keep track of how long the oil has been stored. Store the container in a cool, dark, and dry place, such as a storeroom shelf or a dark cupboard. Avoid placing it near ovens or on top of refrigerators, as heat and light can accelerate the oil's degradation.

Refrigerate or Freeze for Long-Term Storage:

If you plan to store the oil for more than a month, consider refrigerating or freezing it. Very cold temperatures slow down oxidation and the production of peroxides, which are responsible for rancid oil's unpleasant taste and smell. Store the oil in the freezer if possible, as it provides the ideal cold and dark environment.

Reuse Within the Recommended Time Frame:

Used fryer oil can be safely stored for up to three months if properly filtered and stored. However, it is recommended to reuse the oil within a shorter timeframe, as it may develop an unpleasant taste and odour over time. Avoid reusing the oil for deep-frying more than once or twice, as its smoke point decreases after multiple uses.

Inspect the Oil Before Reuse:

Before reusing the stored oil, inspect it for any signs of contamination or degradation. Make sure the oil is clear and has not turned cloudy, which could indicate the presence of impurities. Additionally, check for any unusual odours, as rancid oil may develop a musty or fishy smell. If the oil appears or smells questionable, it's best to discard it and use fresh oil instead.

How to tell if fryer oil has gone bad

Frying oil does not last forever, and it's important to know when it has gone bad. Used frying oil tends to be darker in colour and have a thicker consistency. It may also have a frothy or soapy appearance.

Oil that has gone bad will have an acrid, bitter smell. It will also affect the taste of your food. If your fried food has picked up an unusual flavour or aroma, it could be a sign that your oil is no longer fresh.

Oil can also spoil if it is exposed to sunlight, heat, or air. To extend the life of your frying oil, store it in a cool, dark place away from direct sunlight and heat sources. Seal the container tightly to minimise exposure to air.

Filtering the oil after each use will also help to prolong its life.

How to dispose of fryer oil

There are several ways to dispose of fryer oil, but it's important to note that you should never pour oil down the drain, in the toilet, or into a septic system. Oil can clog your drains and pipes and cause issues with your plumbing. It can also contaminate water, which is difficult, if not impossible, to treat.

• Container method: Pour cooled oil into a disposable, non-recyclable container with a lid, such as a cardboard milk carton or a wax- or plastic-lined paper container. You can then throw the container into the garbage.
• Freezer method: Pour cooled oil into an old can and place it in the freezer. Once the oil has hardened, scoop it out and throw it into the trash. For smaller amounts of oil, you can use a coffee mug instead of a can.
• Plastic bag method: Pour cooled oil into a partially filled plastic trash bag. Make sure to close the bag and include absorbent materials such as paper towels, food scraps, or cat litter to help contain the oil and prevent leaks.
• Combine with other materials: Mix the oil with an absorbent material such as cat litter, sand, or sawdust. Save the mixture in a used container until it's time to empty the litter box, then dump the oil into the litter before tossing it out.
• Grease disposal system: If you frequently fry food, consider purchasing a grease disposal system. It consists of a plastic receptacle with foil-lined bags that can hold up to 32 ounces of oil. Place the bag in the container, pour in the cooled oil, seal the bag when it's full, and throw it in the garbage.
• Recycling: Check if there are any recycling programs or collection points in your area that accept used cooking oil. Some cities have programs for recycling used cooking oil into biodiesel.

How to clean fryer oil

Straining and Storing

After each use, strain the oil through a fine-mesh strainer or sieve into a clean, dry pot or container. If you're cooking flour-dredged foods, you may find a layer of dirty, flour-filled oil at the bottom of the pot. Stop pouring before you reach this layer and discard it separately. Cover the strained oil to prevent dust from falling in and let it cool completely. Then, pour the oil into a sealed container and store it in a cool, dry, dark place, such as a refrigerator or freezer.

Frequency of Cleaning and Storing

The recommended time to keep oil in a deep fryer is a few days to a few weeks, depending on how often it is used. Ideally, the oil should be strained and stored after each use. If you don't strain and store the oil after each use, it can be reused about five to six times. If the oil is strained and the deep fryer is cleaned after each use, it can be reused about eight to ten times.

When to Replace the Oil

Used oil can be stored up to three months after the initial use and still be safe for consumption, as long as it has been filtered and stored in a cool, dark place. If the oil becomes cloudy, foamy, or develops a foul odour, taste, or smell, it should be discarded. Additionally, if the oil reaches its smoking point, it will be dangerous to reuse.

Other Tips

• Use a thermometer to avoid overheating the oil, as this can cause it to break down.
• Keep a fine-mesh strainer by your pot to periodically clean up any bits of batter or breading that may have fallen off your food.
• Stick to battered foods or bare vegetables, as these will impart fewer impurities to the oil than breaded or flour-dredged foods.

How often to change fryer oil

The frequency with which you should change your fryer oil depends on a number of factors. These include the type of oil, the types of food being fried, and the cleanliness of the fryer.

Type of Oil

Some types of oil are more stable than others and have higher smoking points. For example, sustainable palm oil has a smoking point of 230°C and can be used repeatedly without losing quality. Less stable oils, like soybean and rapeseed oil, will degrade faster and give fried food a soggy, greasy texture.

Types of Food Fried

The types of food being fried also play a role in how often fryer oil should be changed. Oil used for frying plain chips can be recycled more than oil used for frying battered or breaded foods. This is because the latter can leave behind small bits and pieces that are continually cooked in the oil, leading to its degradation.

Fryer Cleaning Habits

The cleanliness of the fryer can also impact the lifespan of the oil. While a deep clean "boil out" is only necessary every 3-6 months, filtering the oil should be a daily activity. After each use, the oil should be removed from the fryer, strained, and stored in a cool, dark place until the next use.

When to Replace Frying Oil

There are several signs that indicate it is time to replace frying oil:

• The oil starts to foam.
• The oil turns dark.
• The oil develops a rancid smell.
• Fried foods become less crispy and more soggy.

In general, most oils should be changed after eight to ten uses or if they are more than six months old. However, the frequency of oil changes may vary depending on usage and other factors. For example, in restaurants with high volumes of fried food, the oil may need to be changed daily or every few days, while in homes with less frequent use, the oil may last for several weeks or even months.

Frequently asked questions