@GBTEXBOX
I've bought baking soda at Metro, but I'm sure The Box has it too. What you find in the dictionary, and 苏打粉 as well, should be the right translations for baking soda, although Chinese don't use it that much.

P.S. Farmers and peasants who go tho pick up mushrooms in the woods don't have any kind of contract, probably the hordes of "middlemen" and "brokers" have something like a contract or an agreement, but I'm not sure about it.

Hi all,

I've been working here in kunming as a manager for a company which buys mushrooms in yunnan since 2010. I can say, without being or feeling presumptuous, that we have no way to be sure that wild mushrooms don't have chemical pesticides or things like these. Although mushrooms, especially wild mushrooms, grow spontaneously in woods and forests, there is no control here in China in terms of food safety. Yunnan woods and forests are a way too big to be controlled and, unfortunately, peasants and farmers here are a way to illiterate or not informed on safety quality procedures to understand that they don't have to use sprays or pesticides on mushrooms. This usually happens with all those varieties that are not consumed or eaten by Chinese people, as 白牛肝 － white porcino - is (even if since a couple of months I've heard that Chinese are slowly beginning to use them).

I feel a bit bitter saying this, but I can confirm that at least the 90% of mushrooms you find here in Kunming has been treated with some kind of chemical pesticides or fertilizers. The good news is that some of these things will go away after you clean (i always suggest to use some baking soda powder to clean veggies up) and cook them. Just try to be careful and remember that the nicer veggies and fruit look like, the more chemical pesticides they have. If you want to buy mushrooms (vegetables and fruit in general), then go for the ones which have been a bit eaten by warms: if they eat them, probably they are good!