I wondered about this as soon as I saw it labeled as a Jewish "tax". We've been over this ad nauseum with thebeemer, or ratwell, I can't remember which one it was, maybe both, neither of which are still here.
It's not a tax, no matter how many clueless people call it one. As someone who was in the foodservice industry at many levels, I know what it is and how it works. You'll never understand it if you do your research from the "jewish tax" perspective. In most cases the cost is minimal, unbelievably minimal, and doesn't even get passed along to consumers. The market sets the price, and if it were passed along to the consumer then the more expensive kosher products would be sitting right next to the less expensive non-kosher products and the less expensive products would outsell the kosher products. But that doesn't happen. The prices for kosher and non-kosher are the same. So get the whole notion of having to pay a "kosher tax" or a Jewish tax" out of your head. In any case, the costs pased on to consumers would be in the range of tiny fractions of a penny, if it were to be passed along. The cost of kosher certification is passed along tothe consumer in preceisely the same way that washing your hands in a restaurant is, or the way that sweeping the floor in a processing plant is passed along.
Kosher clingwrap, aluminum foil, sandwich bags, etc., doesn't have anything to do with whether or not Jews can use them, per say. It's more about certifying that they were manufactured, shipped, stored and distributed in such a way that they have not been contaminated. It ensures, for example, that a skid of Zip-Lock sandwich bags have not been stored or shipped along side of a skid of powdered pig lips.
There is no single Jewish authority to interpret the Bible, as interpretations are open what whatever school of thought you have. Some Jews are very strict about things, others not so much. That's why there are different certificiation authorities, as they certify different things in different ways for different reasons.
But as the recent contaminated peanut fiasco has shown, a single raw ingredient can end up in thousands of different products, and if it's to be in a kosher food, then not only does the raw ingredient itself need to be kosher, but also the process that created it, and anything that the process comes in contact with.
Coloring agents, emulsifiers, stabilizers, and a whole host of other ingredients need to be kosher, as well as the process that created them, for a final food product to be laneled as kosher. Food coloring made from shellfish, for example, ain't kosher. Neither is gelatin stablizers of the gelatin is from a non-kosher animal.
Oreos and Chips Ahoy cookies are now finally certified as kosher and carry the Orthodox Union's OU symbol. Jews rejoice. On the other end, a packaging printing error that left the certification symbol off of millions of boxes of Girl Scout cookies rocked the Jewish world when fully and partically consumned boxes of Thin Mints were discovered to be non-kosher. Whoops. Just a printing error folks. Eat up.
Did you know that Kosher Salt is not salt that has been certified as kosher? All salt is kosher. It's a mineral. Kosher Salt is no more kosher than any other salt. It's called Kosher Salt because the size and shape makes it the best kind of salt to use for koshering meat. That's it.