Kettle said:Also, slightly off-topic, but I thought I'd chime in regarding this:
I've never personally known this to be true. I buy all my dairy products from Chinese-owned supermarkets and I've never had rancid anything, nor have I ever spoken to anyone who has personally experienced this. It's my impression that this is just a very widespread rumor, of the sort that typically crops up when a society is confronted with a new immigrant group. Source (in Spanish): El Diario Argentino
"Some" do, mostly don't.