Filtration in breweries has been going on for hundreds of years and we are always looking to do better. Today, we feel we are getting pretty sophisticated. We start the process in the kettle, then move to the whirlpool, additives are currently used in ruh beer, final or polish filtration and then a trap filter. There shouldn't be much left after all of that should there? Let's look back to the Chicago Convention in 1956 and see what their thoughts on filtration were then.