When there is a mixture of permitted and forbidden foods, halakha recognizes a concept called bittul – nullification – that allows the mixture to be eaten under certain circumstances. The Gemara on today’s daf offers a number of examples of this where we find disagreements between Abaye and Rava.
When forbidden aged wine is mixed with fresh grapes, both Abaye and Rava agree that nullification will take place if you cannot taste the wine.
When forbidden “fresh wine” (i.e. grape juice) is mixed with fresh grapes, Abaye says that no nullification can take place, since the taste of the grape juice and the taste of the grapes are the same, so the taste cannot be nullified. Rava argues, claiming that nullification will take place if there are 60 times more permitted grapes than forbidden “fresh wine.” This ruling is based on the fact that grapes and “fresh wine” are known by different names, so they are perceived as separate entities, and nullification will take place when the forbidden product cannot be tasted – or, in our case, where the tastes are the same, when the volume of permitted product is 60 times the forbidden product.
When forbidden vinegar is poured into wine, both Abaye and Rava agree that nullification will take place if you cannot taste the vinegar.
When forbidden wine is poured into vinegar, Abaye says that no nullification will take place since anything that smells like vinegar is considered vinegar even if it still tastes like wine. As soon as the wine is poured into the barrel of vinegar its smell changes and it therefore cannot be nullified. Rava argues, claiming that nullification will take place if there is 60 times more permitted vinegar than forbidden wine since the wine retains its designation as wine even if its smell changes to that of vinegar, so nullification can take place when the volume of permitted product is 60 times the forbidden product.
Some point out that there appears to be a contradiction in Abaye’s two positions. In the first case he seems concerned only with taste, while in this last case he seems concerned with the name of the product (is it considered “wine” or is it “vinegar”?). The Ri”d makes a number of suggestions to answer this question. First he points out that smell is very similar to taste, and since it now smells like vinegar, its taste is considered to be vinegar, as well. Furthermore, once its smell has changed, it is just a matter of time before the taste will change, as well.