If you want to learn more about the science of winemaking or growing grapes, taking an online course from VESTA is a great investment. They have courses on both vineyard management and enology (winemaking). The courses often have a practicum component where you shadow or work for a few hours at a winery or vineyard to get the hands-on experience that can't be done in an online course. Both Ellen Weaver and Scott Sanford have taken courses. If you are interested here is a link to the course catalog - https://www.vesta-usa.org/Students/Course-Catalog.