The Barber Paradox and Kosher Certification

There is a classic logic problem known as the Barber paradox (itself a variant of Russell's paradox): in a town where the barber shaves every man who doesn't shave himself, who shaves the barber? If he shaves himself, then there is a contradiction, and same thing with its opposite.

I was reminded of the Barber paradox when I recently read about an intriguing situation: a product that is kosher only if it doesn't have kosher certification. It's not quite the same thing, but there are some interesting logical properties to this scenario, so it merits exploring.

In Jewish law, a food is kosher only if it consists of entirely kosher ingredients (and milk and meat are not mixed). But there's an exception: if a non-kosher ingredient is included in a small enough quantity (the traditional amount is 1/60th) and is such that it does not add to the flavor, then it's still kosher, but only if it's not done with the intent of being for the benefit of someone who keeps kosher. For example, if you are making chicken soup, and a tiny bit of lard accidentally falls in, but it's a big pot and is undetectable and doesn't change any aspect of the flavor, since it wasn't done for the benefit of the person eating it, it's all fine and kosher. (Note: there are more complications, but this is all that is needed to understand our "paradox")

So now the logic problem: how can a product be kosher only if it's not actually certified kosher?

The elegant (and real) solution: a company wanted to add vitamin D to its milk, and ended up using shark oil to do so. Since shark oil is not kosher, the local certification agency pulled its kosher certification. However, due to a court case, a judge ended up tasting the milk and noted that the oil did not change the flavor of the milk. So now that we know that the non-kosher ingredient didn't change the flavor, we now only have to determine whether it was done for the benefit of the kosher-eating consumer:

One understanding of this position is that anything consciously produced with observant Jews in mind has that issue, even if the observant Jews are a trivial percentage of the intended audience. However, by giving up its kosher certification, Garelick Farms demonstrated that it did not have any concern for observant Jews, and therefore the milk was kosher because it had lost its hekhsher [certification].

Paradoxically, had the KVH accepted this argument and sought to restore the hekhsher, the milk would have become treif [not kosher].

So, there you have it: an instance of a product that is kosher only because it doesn't have any kosher certification. Paradox resolved.

Top image:marsmet545/Flickr/CC