to the baffle disc 20 in coplanar relation thereto as seen in fig4 each adapter 34 has one or more circular series of spaced apertures 26 formed therein to utilize baffles 5 within a still column 12 or 14 a series of baffles are inter connected by fitting the lower reduced cup part 17 in the upper end of tube 18 of the next lower disc 5 so the baffles are arranged in concentric uniformly spaced relation the cup forming part 28 of each baffle is positioned below the downcomer tube 30 of the baffle thereabove mash or grain is fed into the upper end of column 14 through inlet 48 pressurized steam is introduced into the lower end of column 14 through steam inlet 50 as steam rises in column 14 it strikes the baffles successively the concentric ribs 42 and radial ribs 40 serve to retain the steam in the area of the bottom refracting surface 24 of each baffle which it strikes i e between the ribs 42 and 40 so as to direct the steam to and through the adjacent baffle apertures 26 the projection of ribs 42 and 40 below the refracting baffle face 24 prevents the steam from flowing laterally along the lower surface of the baffle as occurs characteristically in stills with the prior type of flat metal baffle because of this ribbed construction less steam pressure is needed to cook the grain and the mash which is supported on upper baffle cooking surfaces 22 and is.