According to a report published in yesterday's Securities Daily《证券日报》, the Chinese stores of mutinational fast food chain KFC only switch the cooking oil they use to fry chicken and fries every 4 or 5 days. KFC have responded to the Securities Daily report by saying that their cooking oil is tested before being used and that their cooking methods meet national standards. Last week, reports criticizing KFC for not using fresh soybeans to make their soybean milk products also circulated online.
Source
Beijing Daily
Google translation