They're over exaggerating the Rarity of wine in the Middle Ages. For context covenants, churches and monasteries would use their cellars wine breweries. While the wine was something expensive it wasn't like only the richest of the rich could afford it. The common person could afford it if they saved up with it. And that's just if you want wine. There are hundreds of different kinds of alcohols that are used in thousands of recipes that the common people would use pretty much every day.