Before the time of Henry VIII, brewing was mostly done at home. The process consisted of mixing very hot water and crushed malt to form a porridgy mash, which was then left for two hours. During this time enzymes in the grain converted the starch into sugars. The sugary liquid or wort as it is known was then run off and cooled. Herbs such as mugwort, alecost, and alehoof were often added to flavour it, and yeast was pitched to ferment it. More hot water was then mixed with the grains to form a second and then third mash. The second mash would make moderate strength ale, and the third would produce a very weak beverage called 'small ale'. This would have been watery, hazy, and full of impurities from the malt. Being only about one or two percent ABV it would only keep at a week for the most, and was consumed in vast quantities (about a gallon a day) as a safer alternative to water. The first running of the malt would produce an astonishingly strong ale which could keep for so long it would have time to clear, and was often saved for celebrations. As all but the strongest of these beverages were prone to spoilage after a short time, they were made in small quantities, often at home. Monks brewed and drank vast amounts of strong ale, and all noble households would have their own brewhouse.
Around the time of Henry VIII, a new style of ale was becoming popular. The difference was an extra process in the brewing - the wort was boiled with hops for a couple of hours, before cooling and fermentation. This enhanced the beverage in many ways; it would clear faster and was less prone to spoilage, so could be kept much longer. This made it economical for much larger quantities to be brewed at once, and so the brewing did not have to be done so often. The new beverage called 'beer' also travelled a lot better, which made it much more possible for brewing to be done on a commercial scale. At first this new method of brewing met with some resistance, but eventually became the norm. Only a few very famous unboiled brews survived, such as Brunswick Mumm, a very strong herb ale, with medicinal properties.
A few strong ales became famous, and were given names such as Stingo, and Tickle Brain. Another popular variation was called Braggot and had honey added to it, to sweeten it and increase the strength.
Francis Greye brewed Braggot, ale, beer, and occasionally the intimidating Stingo, with which to refresh the groupon its travels. Don't drink and drive a wagon!

A medieval-style herbed ale to brew at home