There is a really detailed article on making medieval ale herehttp://www.cs.cmu.edu/~pwp/tofi/medieval_english_ale.htmlA real craft. Monks would have drunk with meals(only two per day remember) as well, much depended on the day and the fasts of the religious calendar. 5 litres a day is mentioned in some sources (although I haven't been able to verify that, and it would surely have been at the top end of consumption)http://www.thefinertimes.com/Middle-Ages/food-in-the-middle-ages.htmlTo be honest we are absolute light weights in drinking terms compared to most periods of history.http://news.bbc.co.uk/1/hi/magazine/4493442.stm And the navy used Rum heavily to replace the beer that spoiled easily: check outhttp://www.webhistoryofengland.com/?p=677Yes, half a pint of rum every day, which might then be diluted to form grog. Think about that. Half a pint doesn't sound a lot, but then get your head round drinking half a pint of rum. Take a nice frosty pint glass and half fill it with rum. then fill the other half with lemon juice and water. Then drink it when hot/cold, climbing masts, hauling ropes and running the guns in and out. Then do that every day. Three Sheets to the wind indeed!Now imagine being a Victorian in squalid parts of London; gin lane, easy girls, disease and plenty of spirits. There is no way a modern, unpractised person would keep up with the consumption levels of previous periods without length habituation periods. I don't know anyone who could knock back a bottle of port, let alone several. Modern light beers like Coors would probably be seen as sort of like weak water.