The environmental temperature, the size of firepower, the thermal conductivity of the cage material, the air permeability between cages, and the density of steamed buns will have different results.

if the closedness of the cages is good, the interlayer is breathable and unobstructed, and the number of layers is not too many, and the firepower is sufficient, steam will fill all the cages from top to bottom, commonly known as round gas, and the top layer will be cooked first when steam condenses to release more heat.

if the fire power is insufficient, or the ventilation between the cages is poor or there are too many layers, or the tightness of the cages is poor, etc., the round gas is too late, and the passing steam plays a greater role, so the lower layer is cooked first.

bamboo steamer classification:

bamboo steamer

Bamboo steamer is made by dividing bamboo into bamboo pieces with a width of about 4 cm, then splicing the bamboo pieces with bamboo sticks and binding the steamer. Because the bamboo in the forest is generally 1-2.5CM thick, it is necessary to scrape off the outer layer with a knife when making it, and then keep the thickness of .5CM to make it. Because bamboo is hard, the outer layer is removed.

bamboo steamer

bamboo steamer is a unique bamboo steamer in Sichuan, Chongqing, Guizhou, Jiangxi and Hunan. Because it is not resistant to cold, it is not widely distributed in the whole country. Its essence is woven materials, so the steamer products are rare, and it is not suitable for making steamer products. Because the thickness of bamboo is about 5CM, it will not exceed 1.5CM, so it is made into a steamer.

Reference: steamer-Baidu Encyclopedia