was difficult or impossible. Though wine of varying qualities was the most common drink in the south, beer was still popular among the lower classes. The idea that beer was consumed more commonly than water during medieval times is considered by some historians to be a myth. Water was cheaper than beer, and towns/villages were built close to sources of fresh water such as rivers, springs, and wells to facilitate easy access to the resource. Though probably one of the most popular drinks in Europe, beer was frequently disdained as being unhealthy, possibly because ancient Greek and more contemporary Arab physicians had little or no experience with the drink. In 1256, the Aldobrandino of Siena described the nature of beer in the following way: The use of hops in beer was written of in 822 by the Carolingian Abbot Adalard of Corbie. Flavoring beer with hops was known at least since the 9th century, but was only gradually adopted because of difficulties in establishing the right proportions of ingredients. Before that, gruit, a mix of various herbs, had been used, but did not have the same preserving properties as hops. Beer flavored without it was often spoiled soon after preparation and could not be exported. The only other alternative was to increase the alcohol content, which was rather expensive. Hopped beer was perfected in the medieval towns of Bohemia by the 13th century. German towns pioneered a new scale of operation with standardized barrel sizes that allowed for large-scale export. Previously beer had been brewed at home, but the production was now successfully replaced by medium-sized operations of about eight to ten people. This type of production spread to Holland in the 14th century and later to Flanders and Brabant, and reached England by the late 15th century. English ale and beer brewing were carried out separately, no brewer being allowed to produce both. The Brewers Company of London stated "no hops, herbs, or other like thing be put into any ale or liquore wherof ale shall be made – but only liquor (water), malt, and yeast." This comment is sometimes misquoted as a prohibition on hopped beer. However, hopped beer was opposed by some: Ale is made of malte and water; and they the which do put any other thynge to ale than is rehersed, except yest, barme, or goddesgood [three words for yeast], doth sophysticat there ale. Ale