I just received an email memo from a renowned kosher certification organization stating that a certain brand of crackers are made with "aged cheese." What is the relevance of this information?
After eating "aged" cheese, one is required to wait a full six hours before eating meat.
The reason for this rule raises a very interesting point of discussion among the early medieval halachic commentaries.
After eating meat before eating dairy, one must wait the amount of time that normally elapses between meals. The projected time between meals is six hours.
Why the wait?
Two reasons are given. Maimonides writes that meat is stringy and gets stuck between the teeth; after six hours any meat residue has been rendered distasteful and is therefore not a matter of concern.
According to others, meat's pungent taste and odor, which is felt long after the meat has been eaten, is the reason for the mandatory wait.
Neither of these two reasons apply to dairy foods, and therefore no extended wait is required after eating dairy before consuming meat.
Aged cheese, however, while not stringy, does have a pungent taste. Thus, due to the second reasoning mentioned above, after eating such cheese it is necessary to wait six hours before eating meat.
The consensus among the latter authorities is that cheese which has undergone a proper fermenting process is sufficiently strong to warrant a six hour break before meat is eaten.
The memo which you received was alerting readers that that product contained aged cheesed and therefore warranted the longer wait.
For more on the laws of Kosher, see our Kosher Handbook
Rabbi Menachem Posner