Diagram showing the classification of beers, mainly from the point of view of the yeast. Before making any kind of critic or suggestion, please read the following text!!. After I have published it, there was quite a long discussion about it. If you have any disagreement about the chart, please check whether I have already answered your question.

• I made it collecting information only from en.wikipedia and re-arranging. Since it just mirrors the classification that was already in Wikipedia, the chart is not an original work and can be used in wikipedia itself. Unless I made some mistakes copying, the chart just reflects what is in en.wikipedia. If you find any error, it is possible that there is an error on the relative article on the English wikipedia as well. Fix that first, and I'll fix the chart according to that.
• I have used English words whenever possible, but I have used the words in original language (mainly German) when you can easily find those words on bottles. I hope this is not confusing
• I ignored hybrid beers, because they can't be classified in a chart like this since they are a mix of different types. I made an exception with Weizenbock because is quite common, and it appears in two different places because it is both a wheat beer and a bock. We can discuss about removing it completely.
• types on the same "logical level" are ordered alphabetically.
• I wanted the text to be as short as possible. For example, under "Stout" I just wrote "Milk", meaning "Milk Stout". I did not do the same with "Dry stout" because it could be confused with "Dry lager"
• I kept the types of beers as few as possible. I have some doubts about "Abbey beer", since it's just an Ale with the name of an Abbey (so it does not refer to the taste) and "American Pale Ale" (is it so different from a standard Pale Ale to be defined separately??)
• dubbel, tripel and quadrupel can be only abbey or trappist beers, so they are actually a subsection of those two types. I couldn't think about any smart way of showing this on the chart, so I just put them on the same "logical level", even if it is not strictly correct. If you have any suggestion about how to solve this problem, it's welcome :-)
• the style of the lay-out is very basic because I think there will be some discussions in the future, so it can be changed easily. In the future I want to try to make it look more "fancy"
• lambics are considered other than ales and lagers, because in general lambics can be both top or bottom fermenting. Moreover, they are made with wild yeast, while ales and lagers are not, so they have their own space in the chart
• Belgian ale and Dark ale are not meant to be kind of beers, by a way to group the sub-categories
• by Belgian ale I meant all the particular ales that can't be classified as anything else and that were invented in Belgium. I can agree about replacing it with "Special ale", but before we should make a "Special ale" article on en.wiki (while the article "Belgian ale" already exists).
• about beers with multiple names (such as Weissbier-Weizenbier-wheat beer-white beer-bier blanche) I just have used the most common one. If you disagree with my choice, we can talk about it.
• I know that Saison is a complex type of beer, it's much more than a standard pale ale, but according to the relative article on en.wiki: Saison is the name given to pale ales brewed in Wallonia; so it deserves to be a pale ale in the chart.
• this chart is a simplification of a complex argument, but making a chart is exactly about giving a clear and simple overview, if you want more details just read the relative article on wikipedia! I believe a chart is better (even if less precise) than a list or a table because points out clearly the logical links between the different kinds. If you want to make a list as well, you are absolutely welcome, but I still find the chart approach more useful.