You get free access to the museum with the purchase of the castle visit. I'm not sure if one can go just to the museum. Castle is definitely worth visiting, but the museum for us was an afterthought..

We did the Cata de vino, visita al Museo y al Castilo. I really loved the wine tasting with the castle’s sommelier. Although my Spanish is rudimentary, my wine knowledge is pretty solid, so I got a l.

Visita muy interesante la de este museo en la cual te enseñan todo el proceso del vino.Interactuas con diversos olores.