Turbot's Really Odd (real ale)
Given the general state of the river Ankh, any casual student of Roundworld history might reflect that Ankh-Morpork is at a stage in its history where, for example, Paris, France was at the time of its Revolution. With no knowledge of germs or walruses, the water used for baking bread (and Marie Antoinette's cakes) was drawn directly from the Seine, a river that also functioned as sewer, dump, and occasional cemetery. While people still ate the bread (and cakes), they were also aware of a causal link between Seine water and debilitating diseases such as cholera. Therefore wine and beer were the preferred beverages - not from choice but necessity, for as we now know, the alcohol content of the wine acted as a crude purifying agent and kept disease at bay while the water was boiled to brew the beer. An example of this is during the Broad Street Cholera Outbreak, when it was noted that practically the only people in the area not suffering Cholera were the brewery workers, who had ready access to beer.
This would have been the case for most of European history in most towns and cities up until the late nineteenth century. It is therefore a sobering point to reflect on how many important decisions were taken by leaders of government who would have been more than slightly drunk by dinnertime... Ridcully, however, appears to thrive on his diet of beer with everything and has not taken any noticeably erratic decisions during his tenure as Archchancellor. Lord Vetinari considers a glass of water to be a sufficiency, but it has been pointed out that he has it boiled.