A lautering system developed by Steinecker, in which air is excluded from the lauter tun using carbon dioxide, the pressure of which is increased to between 15 and 35 mbar above atmospheric during first wort collection and again during sparging (beginning at atmospheric pressure in each case), was evaluated in comparison to conventional lautering following the installation of lauter tuns of this type at the Jinro-Coors Brewery in Cheongwon, South Korea. It was found that the flow of wort out of the mash was accelerated at the higher pressure (in this case 25 mbar above atmospheric), shortening the time required to complete the process by an average of 19 minutes. The quantity of sparging liquor required was reduced, as was the moisture content of the spent grains. Wort composition was little affected, except for pH, which was slightly higher in the pressure lautered worts (contrary to the expectation that the dissolution of carbon dioxide might cause a lowering of pH) and turbidity, which was lower. Otherwise the worts and beers were practically identical. Beers made from pressure lautered worts were found to have slightly lower intensities of undesirable flavour notes (astringent, harsh or sour) when fresh, indicating that the exclusion of air during lautering may have reduced the extent to which wort constituents underwent oxidation, but their long term flavour stability was not significantly affected.
Keywords : beer carbon dioxide composition lautering performance pressure quality wort