1. Look at the color. The color of the oil is transparent, while the gutter oil has a variety of chemical compositions, will be cloudy and opaque, and there may be precipitation at the bottom of the bottle. This kind of inferior oil is mostly seen in the bulk oil wholesale market, and there are also small restaurants on the street, which may also use inferior oil.

2. Smell. Qualified oil will have the flavor of the fat itself, such as peanut oil will have the flavor of peanuts; olive oil will have the fragrance of olives. Gutter oil is not the fat itself should have the flavor, smell, you can smell a little sour, there is a strange chemical composition of the smell.

3. Taste. Usually buy oil is to see the color and smell to identify, but the chef in the buy back oil will use chopsticks to dip a drop of oil to the palm of the hand, gently rubbed, and then lick a little palm of the oil with the tip of the tongue, the normal oil will taste fragrant, such as peanut oil will taste peanut taste, but the gutter oil tastes sour, there is also a bitter taste. The entire chef industry is most commonly used in these three simple methods, consumers can also usually use these three methods to identify, feel bad oil do not consume.

4. After consumption. The oil used in the dishes in the restaurant is doctored, so it is difficult to identify. But after eating dishes made with gutter oil, your stomach will be bloated, your stomach and intestines will feel uncomfortable, and you will have indigestion. This method may not quite be called a method because it has to be eaten first before there can be an uncomfortable reaction.

Street vendors and small restaurants generally use cheaper oil in bulk to cut costs, so the probability of using gutter oil is higher. Consumers dining out, you can choose a larger restaurant, branded and reputable restaurants, because they purchase cooking oil channels formal, generally can be more assured.