1, poor variety: the variety of lettuce itself is poor, and it contains a lot of lettuce, which makes it bitter to eat. Methods to remove bitterness: blanch lettuce once before frying, or marinate it with salt for about half an hour before frying, which can generally remove bitterness.

2. The bitter taste of lettuce is caused by one substance, namely lettuce. Lettuce may encounter some problems such as water shortage during its growth and development, and the element of lettuce may increase with these factors. However, lettuce is not a toxin, and even if it is eaten, it will not have too many side effects, so lettuce can be eaten when it is bitter.