Oh look it's Google expert. Guess fucking what not everything on the internet is true. Try reading medieval literature and you will discover the alewife, but don't bother with centuries of contemporary writing let's go to blog on food.
First of all, alewives brewed for commercial sale to make income. They didn't produce it as a substitute for drinking water for the home.
Second making enough of it to stay hydrated would have consumed an entire household's day in labor every single day. Even with modern conveniences and advanced, specialized tools, it takes me and a buddy 12 hours of work to make and clean up after 20 gallons made in four batches. The complications of gathering the massive amount of firewood and the incredibly primitive tools make this entire "beer was used instead of water" thing absurd.
Third, and most significant:
beer dehydrates you! Ethanol is a diuretic. I suppose if "beer" were <1% alcohol this problem wouldn't show up, but at that point any preservative effects of ethanol are nonexistent. Not only that, but medieval gruit ales (so, anything before the 13th century at the earliest, 15th for late adopting regions) had poor antimicrobial properties compared to hopped beers. Not to mention, if beer consumption were that totally dominant over water, every child would have been born with fetal alcohol syndrome.
We can be sure they drank a lot of it. Beer does carry nutrients and "store" grains that would otherwise spoil effectively, but the idea that people would substitute it entirely in place of water is just ridiculous.
