This just in from the Zythophile blog:
By itself this does not prove hops were used in beer, just “in drinks” (in potibus in Hildegard’s original Latin). But in a later chapter, on the ash tree, the abbess wrote: “If you also wish to make beer from oats without hops, but just with grusz [gruit], you should boil it after adding a very large number of ash leaves. That type of beer purges the stomach of the drinker, and renders his heart [literally ‘chest’ or ‘breast’] light and joyous.” Clearly Hildegard knew about brewing beer with hops. The passage also suggests that Hildegard knew about boiling wort, without which just adding hops is not much help in keeping away “putrefactions”.”