By the way, the traditional, old-school long-banned but non-necessarily forgotten filter is bull's blood. Some top French vitners still use it, even though they face steep fines and penalties, because it simply works better than any of the alternatives.
How about the sulfuric acid used in French wines, either from a bottle or by burning chunks of sulfur on sticks inside the barrels?
Wouldn't bull's blood make the wine non-Kosher?
This is why I only drink Kosher wine.