As far back as the Stone Age, beer was a household staple for most families in England and other parts of Europe. The drink was an inexpensive way to consume and preserve grains. For the working class, beer provided an important source of nutrients, full of carbohydrates and proteins. Because the beverage was such a common part of the average person’s diet, fermenting was, for many women, one of their normal household tasks.
During the Middle Ages, some enterprising women took this household skill to the marketplace and began selling beer. Widows or unmarried women used their fermentation prowess to earn some extra money, while married women partnered with their husbands to run their beer business. The women often stood in front of big cauldrons while wearing tall, pointy hats so they could be seen amongst the crowded marketplace
But when the fundamentalist religious movement began, preaching stricter gender norms and condemning witchcraft, male brewers saw an opportunity. To reduce their competition in the beer trade, these men accused female brewers of being witches and using their cauldrons to brew up magic potions instead of beer.
See the full story from the Smithsonian here.