Yes, blanching can remove oxalic acid from lettuce leaves. If you eat it directly, it will be particularly sour and a little bitter.

Blanching method:

Put lettuce and leaves in boiling water, and then take them out immediately.

Lettuce (scientific name: Lactuca sativa L. var. angustanairish.), also known as lettuce, belongs to the genus Lactuca in Compositae, which can form a variety of tender stems and is a biennial herb. Alias lettuce, lettuce, green shoots, lettuce. Date of birth:1-April. Native to China, Central China or North China. The above-ground stems are edible, the skin is white and green, the meat is crisp and tender, the young stems are green, and they turn white and green after maturity. Young stems can be eaten raw, cold, fried, dried or pickled, and young leaves can also be eaten.