While figures vary widely depending on water to grist ratio, beer strength, size of brew house, etc., a typical volume of 2L of water is used to produce 1L of the sugar rich wort from the crushed malting barley and to rinse the mash, kettle and pipework following the brewing process. Typically, the wort is cooled with water and the ratio of cooling water to wort depends on the cooling water temperature and heat exchanger efficiency but a ratio of 1,5L cooling water per litre of hot wort is typical. If the cooling water is not recovered for reuse then approximately 3,5L of water is required to produce 1L of cooled wort ready for inoculation with yeast. However, studies have shown that, depending on microbrewery size and efficiency, up to an additional 3L of water/L beer is required for ancillary steps. A significant portion of this extra water is in fact used for cleaning and rinsing as opposed to the direct beer manufacturing. Additionally a lot of this water must be heated which consumes additional energy usage. Most people don’t realise that water really requires a lot of energy to increase its temperature, in thermodynamics water is said to have a very high “specific heat”, consider the following;
4.184kJ of energy is required to heat 1kg of water by just 1°C.
In comparison only 0.490kJ of energy is required to heat 1kg of steel by 1°C. That’s 8.5 times more energy required to heat water than steel by 1°C!
(Ref: Engineering toolbox.com).
Equipment cleaning is both time and resource consuming and is not what is deemed “value added” work but it is absolutely critical to ensuring beer quality.
We’re well aware of the fact that water requirements for the production of the raw materials (barley & hops) used in beer production are much higher than what’s used in the brewery but every litre of water saved, every litre of cleaning and sanitising agents saved and every kW of energy saved helps in the strive for sustainability. That’s why brewers who use the SURF technology can use marketing slogans such as “Save the World, drink our Beer!!”