The idea is you taste the wines as you walk round using the little tasting dish given out at the ticket office.
Firstly if you try them all you will be unconsious when you emerge at the other side.
Secondly the good wines are all at the end of the tour, with the cheaper ones at the beginning. So its really best to ignore the wines at the start, at least dont drink them. Get nearer the end and start tasting there, your tastebuds and your head will thank you.,