If people really were the connoisseurs they think they are, these frauds would be impossible. In fact you can change the label on a lot of things and people don't notice.
In the UK we have a very popular tv program 'Masterchef'. Last week 5 competitors were asked to identify the ingredients in a meal of spicy pork. They got most of the spices and sauces right, but two of them identifed the meat as lamb and one as duck.
And these were excellent amateur chefs aiming to become professionals.
The Sock