1. Kerning: After picking acorns with shells, insects will be born in less than 5 days; Fresh kernels contain more water and are prone to fever and mildew, so they should be treated in time after harvesting. When harvesting, you can spread a layer of plastic film on the ground, pat the ripe fruit with a bamboo pole, remove impurities such as leaves and branches, immediately dry it in the hot sun, and whip it with a whip to separate the sub-shell from the shell barrel. In case of rainy days, it can be dried by fire to prevent mildew. We still need to take off the hull. This method can be broken with a mortar hammer or shelled with a rice mill, and then the shells are scraped off with wind, and the nuts are washed and dried. Per 100 kg, about 60 ~ 70 kg of clean kernels can be obtained.

2. Extraction of starch: soak the nuts in water for 1 ~ 2 days, change the water for 1 ~ 2 times a day, remove the astringency, grind them into pulp with a stone mill, put them into a container such as a tank, pour off the water after precipitation, then filter and dry the filtrate to obtain starch. 30 ~ 50 kg of acorn powder can be extracted per 100 kg of acorn.

Acorn starch is rich in a variety of nutrients beneficial to human body: fat, starch, protein, tannin, calcium, potassium, sodium, magnesium, iron, selenium and other elements, especially tannin is a rare top grade that cannot be replaced by other elements. Compendium of Materia Medica claims that it is low-calorie, non-toxic and nutritious, while Dictionary of Traditional Chinese Medicine points out that acorn powder can strengthen people and astringent intestines, and treat diarrhea, proctoptosis and hemorrhoids; The Complete Collection of Rural Food in China is known as "the homology of medicine and food". Our immediate neighbors, Russia and North Korea, especially like food.