Why is sugar fried chestnuts packed in paper bags?
The freshly fried chestnuts are steaming, and when they are taken out, the heat will turn into water. If it is a plastic bag, the water droplets will condense inside, and it is hot water, before you finish eating, the chestnuts inside will become as boiled and difficult to eat.
If it is a paper bag, the paper will absorb the moisture, which will not affect the taste of chestnuts.
Paper bags containing fried chestnuts are very thick, but thin ones are not.