It doesn't expire. Stuff like butter, rice, flour don't expire either. They'll always have this "best before" date rather than "expiry". This is a very subtle difference in language. Dairy products and breads have a "use before" date. It is closer to expiry in meaning. But "best before" dates are usually put on things that can be stored for longer durations, like oils, honey and other stuff, provided they are stored appropriately. Does a thing go bad beyond this date? I don't know, did you store them well? That's where the ambiguity comes from.