Common problems in microbreweries arising from poorly planned brewhouse facilities are discussed together with their solutions. The most common type of brewhouse plant in US microbreweries comprises a hot liquor tank, a traditional mash tun (i.e. a combined infusion mashing vessel and lauter tun), a combined wort copper and whirlpool, and a heat exchanger for wort cooling. Production capacity is normally about 20 US barrels (23.5 hl) of wort per brew. The author recommends that when such a brewhouse plant is installed, provision should be made for the installation of a mash conversion vessel separate from the mash tun (which could then be used simply as a lauter tun) and a second copper/whirlpool (which could also be used as a mash portion cooker for decoction mashing) as well as for automatic mashing temperature/time control, even if there is no intention to install these facilities immediately, as the ability to add them rapidly and easily is very useful if it is planned to increase production capacity or to brew certain continental European beer styles (e.g. German or Belgian wheat beers). If the beer is being sold into the mainstream beer trade, the brewhouse equipment should be designed to minimize oxygen pickup during the recirculation of cloudy first wort and the transfer of wort from the mash/lauter tun to the copper, although this may not be necessary in public house breweries where all the beer is consumed on the premises very shortly after being finished. A common problem is insufficient hot liquor capacity; the tank volume should be at least twice (preferably 2.5 times) the brewlength, but many microbrewery hot liquor tanks are significantly smaller. Wort cooling systems often use tap water, which in summer (especially in the southern USA) can be much too warm for the purpose, and the author therefore recommends using an insulated tank to store water chilled with glycol from a small refrigeration unit. It is also pointed out that the typical microbrewery brewhouse plant layout entails a number of serious hazards to workplace safety, including the installation of the vessels on a metal platform (which is slippery when wet and may be 1.5 metres or more above a concrete floor), the close proximity of the vessels (so that if one brew is being mashed while wort from a previous brew is being boiled, the brewer at the mash tun has a copper of boiling wort right behind his/her back, and could be very severely injured if the wort were to boil over, as is not uncommon in coppers without a sensor actuated emergency heat cutoff), the location of the control panel on the wall at the back of the platform (where it would be inaccessible if the wort boiled over and the brewer was not on the platform), the use of full mains voltage for low powered electrical equipment for which much lower voltages would be equally effective and much safer, and the positioning of the hot liquor tank inspection/cleaning hatch at the side of the tank where its accidental release could be disastrous and possibly even lethal.
Keywords : brewhouse design efficiency equipment microbrewing safety