That hops could be used for flavoring beer had been known at least since Carolingian times, but was adopted gradually due to difficulties in establishing the appropriate proportions. Before the widespread use of hops, gruit, a mix of various herbs, had been used. Gruit had the same preserving properties as hops, though less reliable depending on what herbs were in it, and the end result was much more variable. Another flavoring method was to increase the alcohol content, but this was more expensive and lent the beer the undesired characteristic of being a quick and heavy intoxicant. Hops may have been widely used in England in the tenth century; they were grown in Austria by 1208 and in Finland by 1249, and possibly much earlier.