To reuse cooking oil without tasting whatever was cooked in the oil previously, cook a 1/4″ piece of ginger in the oil. It will remove any remaining flavours and odours.
Ginger is the key. However, you have to use it properly. You must use the proper amount of ginger for the volume of cooking oil you wish to deodorise, and the temperature must be just right.

Yet first… Is it okay to use leftover frying oil?
To be clear, in this piece we’re referring to deep-frying oil. It takes many cups to ensure that whole fish or huge fish fillets are completely submerged in oil when frying. And with only one usage, that is a lot of oil to discard.
So we recycle. Yet, is it secure? Well, if you read papers published by cooking oil producers, they advise you to discard the oil. But the purpose of that is to have you use fresh oil each time you deep fry something, which means more sales for them.
ADVICE FOR KEEPING SPENT FRYING OIL SAFE
- To begin with, let the oil in the pan cool until it reaches room temperature.
- Pour the oil through a strainer into a clean, covered container (we use glass bottles or jars, as appropriate). For any visible impurities, use a fine mesh or two to three layers of cheesecloth.
- Ginger can be used to get rid of the taste and smell of fish if you’re not using it to fry fish again.
USE GINGER TO GET RID OF USED COOKING OIL’S FISHY SMELL.
How versatile ginger is! Despite the fact that ginger is more adaptable, ginger is perhaps my favourite spice. Use it to flavour food while sautéing, turn it into a paste to use as a marinade, or prepare ginger drink by simmering fresh ginger slices in water.However, did you know that ginger may be used to effectively eliminate the fishy flavour and taste from frying oil? I picked up this trick from my hubby. You can see that I don’t waste cooking oil after just one usage. It’s just too wasteful. So I recycle. However, I make an effort to get rid of as much of the fishy flavour and smell before using the oil to cook anything else.
Take a piece of ginger (a thumb-sized piece for every cup of cooking oil works fine for me) and slice. No need to peel — just slice.A wok or pan should be filled with discarded cooking oil. Keep the stove’s lowest setting while gently heating. Place the ginger slices in the oil, and then give them 15 minutes to soak. If your oil is just the proper temperature, the ginger slices won’t burn but rather gently turn golden brown.Scoop out the ginger after fifteen minutes. Fishy flavour and odour are no longer present in the cooking oil.

HOW MANY TIMES CAN YOU REUSE FRYING OIL?
Depending on what you initially fried in it. We don’t use it more than three times if fish or meat were fried in it. We can reuse oil up to six times when frying foods with more neutral flavour and aroma, like tofu or potatoes.