Step 1

Place a fine-mesh strainer over a heat-safe bowl and set aside.

Step 2

In a small dish, whisk together water and cornstarch to create a slurry. Set aside.

Step 3

Pour your used cooking oil into a large pot.

Step 4

Pour the cornstarch slurry into the pot with the used cooking oil.

Step 5

Heat this mixture over low heat. (You don't want it to simmer.) Occasionally, stir and scrape the bottom of the pot. This process takes about 10-12 minutes. You know it is done when the cornstarch has all come together, becomes a solid, and has collected all of the debris.

Step 6

Remove oil from heat and pour it into the fine mesh strainer. (You can also use a couple of layers of cheesecloth.)

Step 7

Discard the cornstarch mixture.

Step 8

Allow the oil to cool completely before storing. The oil will look cloudy at first but will settle as it cools.

Step 9

Refrigerate the clarified oil.