No they don't. The grains are contained in a malt pipe that are simply lifted out of the vessel in a very similar manner to a BIAB setup. If you mill your grains too fine you will get wort fountains shooting out the top though.Eagleburger said:do the BM get stuck sparges as easy as a conventional mash tun?
As far as the price of a BM goes, yeah, they aren't cheap as far as home brewing equipment goes but compare them to other hobbies like boats or cars and they don't seem too bad. The BM is easily one of the best things I've ever bought.