The drink by function with PWC is auto. You have to have the wine's varietal, distinction, year and region entered. You then just click the button and it tells you when you should drink it, and also the drink by date. Some bottles of mine it couldn't give me data because they are an "un-known" to the software. For example, I have some Wattle Creek Malbecs from the Alexander Valley region. It didn't recognize that. Apearently, there aren't many Malbecs in Napa...

There's a bunch of other things you can do with it, like pair foods and enter menus and different ratings, but I haven't messed with those much.