Chullin 99: How to Taste Whether or not Something is Kosher

Over the dapim Chullin 97 and 98, the rabbis have discussed the ruling that one sixtieth of non-kosher content will not cause the entire kosher whole to become forbidden.  The rabbis have argued about which exact ratio might be permitted and under which circumstances there might be flexibility.

In Chullin 96, a Mishna taught that if the gid hanasheh, sciatic nerve, had not been removed when the thigh was cooked so that there was enough forbidden flavour to affect the meat of the thigh, it is forbidden.  How is this measured? The Mishna explains that we compare it to meat cooked with turnips.  Today's daf has Rav Huna's explanation.The meat and turnips would be cooked in the same proportions as the thigh and sciatic nerve.  If the meat flavours the turnips then the thigh would be forbidden.  And as the Sages have estimated, meat cannot transfer its taste to any substance that is cooked where the substance is sixty times larger in bulk than the meat. 

The rabbis wonder how it would be possible to estimate a forbidden flavour.  First of all, all meats have a similar taste.  Secondly, a Jew might accidentally taste what is forbidden.  Third, the Chatam Sofer argues that a non-Jew would not be familiar with Jewish flavours.  Thus because non-Jews always eat the thigh with the sciatic nerve attached, s/he would not be able to accurately judge a change in the flavour of the meat.

The Gemara notes that Yishmael ben Rabbi Yochanan ben Beroka disagrees with the Mishna.  He rules that the gid hanasheh has no taste at all and cannot transfer its flavour into the meat surrounding it.  This opinion is accepted by the rabbis.  It is interesting that the rabbis are willing to concede that the sciatic nerve has no flavour when no-one has in fact tasted it.