How to Clean Dark Cooking Oil: 15 Steps

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How to Clean Dark Cooking Oil: 15 Steps
How to Clean Dark Cooking Oil: 15 Steps

Often, after preparing some frying at home, the result can be a very dirty and dark oil. The good news is that as long as you filter the oil, you can reuse it. You'll be able to save a little with the techniques below, but always remember to check the oil before reusing it to make sure it's not spoiled.


Part 1 of 3: Cleaning up cooking oil

Clean Dark Cooking Oil Step 1

Step 1. Filter the oil

When you fry something, the food ends up dropping chunks into the oil. Filtering will help remove some of the debris, but some other techniques may be needed to get you all out. Using a slotted spoon is the first step in removing the larger pieces.

  • Use a slotted spoon to remove floating pieces of food from the oil and dispose of them in the trash. If possible, use the slotted spoon to clean the oil during frying.
  • Buy a slotted spoon at any supermarket, cookery store, or online store. There are skimmers of all types and values, but usually you don't need to spend a lot.
Clean Dark Cooking Oil Step 2

Step 2. Strain the oil

After removing the large pieces of food with the slotted spoon, the next step is to use a sieve. You'll filter the oil to remove smaller sediment, leaving the oil cleaner and food-free. You will need a fine metal or calico sieve for the process.

  • Allow the oil to cool before straining it.
  • Set aside a clean pot or other container. Pour the oil through the sieve over the container, being careful not to turn the pan too quickly and make a mess. The rest of the oil in the pan tends to have a lot of sediment; discard it completely.
  • If you don't have a sieve, stretch a piece of cheesecloth over a funnel or use a coffee filter.
  • If you have difficulty pouring the oil in slowly, use a measuring cup or ladle to strain it out bit by bit.
Clean Dark Cooking Oil Step 3

Step 3. Return the oil to the previous container

After straining, you can return the oil to the container with a funnel, provided it is suitable for storing the product. Obviously, be careful not to put the hot product in a plastic container.

  • Only use the original container again if you used all its oil in the frying. Never add dirty used oil to new oil.
  • Do not cap the container until the oil has completely cooled.
Clean Dark Cooking Oil Step 4

Step 4. Store oil well

The use in frying is not the only one responsible for the degradation of the oil. The storage method greatly influences the process: it is necessary to keep the product away from moisture, light and heat to keep it in good condition.

  • The presence of light and heat during oil storage reduces the possibility of reusing the product.
  • Do not store the oil above the stove, as doing so will subject the product to the secondary heat of the fire.
  • Store oil in a cool place away from direct light. If you have space, keep it in the fridge; it will become thicker and whiter, but just let it return to room temperature before using it.
Clean Dark Cooking Oil Step 5

Step 5. Reuse the oil correctly

Know that the oil will always have the odor of the last food fried in it. For example, if you used an oil to fry fish, you can reuse it to fry other fish and meat, but frying sweets in it will leave a taste in the food.

  • Store oils separately. If you used an oil to fry fish, store it in a proper container so as not to use it when frying something sweet, for example.
  • Identify bottles according to the fried foods and the date of use.
  • Reusing the oil is good for the pocket. Some oils are often quite expensive, and reusing them will help you save a lot. The important thing is to think about your health and not reuse oil forever.
Clean Dark Cooking Oil Step 6

Step 6. Reuse the oil in other recipes

The fact that you have used the oil to make submerged frying does not mean that it cannot be used for other types of preparation. You can, for example, use it to fry a steak or chicken fillet.

You can also use oil in baked recipes. Just remember that it will retain the tastes and smells of foods that have been fried; always reuse the oil with similar foods

Part 2 of 3: Keeping the Oil Clean

Clean Dark Cooking Oil Step 7

Step 1. Choose oils with high smoke points

The smoke point is the temperature at which the oil starts to smoke, where it starts to degrade more quickly. Choosing an oil with a medium or high point means it will not degrade too much during use.

  • Sunflower oil, palm oil (palm oil) and avocado oil have excellent high smoke points for frying.
  • Peanut oil, canola oil and grape seed oil have medium smoke points and can also be used in frying.
  • Refined oils can be heated to higher temperatures than crude oils, which makes them a better option for reuse. For example, refined (or "light) olive oil can be reused a lot, but the same is not true for extra virgin olive oil.
Clean Dark Cooking Oil Step 8

Step 2. Check the type of food you put in the oil

To maintain the oil's color and consistency, only fry foods that don't shed too many pieces behind. Any leftover food already starts to degrade the product.

  • For example, frying breaded foods leaves more food scraps in the oil than frying battered foods.
  • Foods simply sprinkled on flour tend to leave a lot of residue in the oil.
Clean Dark Cooking Oil Step 9

Step 3. Invest in an electric fryer

Oils used in restaurants tend to degrade more slowly due to the operation of fryers. Basically, the machines have a cooler area at the bottom where the food doesn't burn. The only way to replicate this effect at home is to buy an electric fryer.

As expensive as this investment is, it can be worth it if you do a lot of frying at home. In addition to helping control the oil temperature and facilitating reuse

Clean Dark Cooking Oil Step 10

Step 4. Do not overheat the oil

Doing so will make it useless more quickly. The opposite is also bad: using the oil at low temperatures will prolong the frying time, increasing the number of food debris in the oil. The ideal is always to fry a little below the smoke point of the oil used - when in doubt, do an internet search to find out which point of the oil you are using.

  • Use a frying thermometer to keep an eye on the temperature. Maintaining the ideal oil temperature will increase the frequency of reuse and improve the taste of foods.
  • Turn off the heat when finished frying. The longer you keep the fire burning, the more likely it is that the oil will degrade. The product will be dark in one hour to the point where it can no longer be reused; keep it at the ideal temperature to be able to clean and reuse it.
  • Most oils with medium and high smoke points can withstand temperatures of at least 200 °C, but some can go well beyond that. Avocado oil, for example, has a smoke point of 270 °C.

Part 3 of 3: Knowing when to dispose of oil

Clean Dark Cooking Oil Step 11

Step 1. Replace the oil when it is too dark or foamy

Sometimes you have to accept defeat and change the oil; knowing the right time can be difficult, but there are some signs that the oil is old and should no longer be reused. If the oil remains dark even after it's filtered, or if it's foamy, it's time to throw it away.

  • Over time, the oil will start to soak the food too quickly, leaving it looking greasy rather than crunchy.
  • A foamed oil will smoke too soon, preventing frying at the ideal temperature.
Clean Dark Cooking Oil Step 12

Step 2. Smell the oil

When old, the oils go through the rancidity process, which leaves a very unpleasant odor. When taking the oil and putting it in the pan, smell it and see if it is possible to reuse it. If it smells bad, discard it so you don't risk spoiling the food.

  • A rancid oil is unlikely to be bad for your health at one time or another, but the food will taste bad and heartburn is almost certain.
  • Using rancid oil will leave food with a rotten fishy smell as well as an ugly face.
Clean Dark Cooking Oil Step 13

Step 3. Observe consistency

On first use, the oil should spread smoothly through the pan, with the exception of solid oils at room temperature such as coconut oil. As they degrade, the consistency starts to get thicker. When the oil is thick or sticky, it's time to dispose of it.

If you chose to store the oil in the refrigerator, remember that this will make it thicker. Allow the product to return to room temperature before checking its consistency

Clean Dark Cooking Oil Step 14

Step 4. Dispose of oil responsibly

Now that you know you need to throw it away, there are some precautions to take. Never pour the oil down the sink drain, as you will clog the pipes in the house and in the rest of the city.

  • The best way to dispose of the oil is to put it in a container you already planned to dispose of. Obviously, don't put hot oil in a plastic container.
  • Even if you dump oil in the sink with hot water, it's likely to get stuck in the pipes. Improper oil disposal is one of the main causes of congestion problems in sewage systems. Product build-up in pipelines over time can be quite expensive in repairs.
  • Never pour cooking oil into a manhole, as doing so can impact the environment. It's no use mixing the oil with hot water and detergent.
  • Some disposal centers may accept the use of used oil to help the environment. Check your local city hall website to find out what your options are.
Clean Dark Cooking Oil Step 15

Step 5. Think about security

Submerged frying can be dangerous as temperatures sometimes exceed 200 °C. Be careful not to burn yourself and don't get too close to the hot oil. Use a protective screen over the fryer to prevent splashing.

  • Oil is extremely flammable, making it a fire hazard when working near an open flame. Equip your kitchen with a fire extinguisher to protect yourself at all times. The contact of water with hot oil turns it into steam instantly, creating dangerous splashes. Be very careful not to spill water on the oil while frying.
  • If the oil catches fire, do not quench it with water; doing so will only spread the oil further. If you don't have a fire extinguisher, cover the fryer with a metal lid and call 911 immediately.
  • If you have children at home, use oil only on fires behind the stove. That way, you don't run the risk of the little ones dropping the pot and getting burned.
  • Read the manual before using a submersion fryer. Do not pour oil into the fryer until it is off, dry and clean.


  • Using water to "wash" the oil will not work at all.
  • You'll know the oil isn't good when it's dark and making food taste bad.

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