Agreed, I think it is one liter per person, unless it is locally made stuff, like Ma Dou Dou. Regardless, you can bring back as much as you like (for personal use) and just declare it and the worst that can happen is that you will have to pay duty, which is something like 10%. Just declare it regardless and usually they don't charge you duty. If you DON'T declare it, could be big legal problems though.