Water supplies are already running short in some parts of the world and some parts of the UK are in water deficit. Malting needs large volumes of clean water for its process, and classically has used around 4m3 for each tonne of malt produced. Efforts to reduce water consumption have reduced this, and further work will bring the figure down further.
The SWAN water project undertaken by UK and French maltsters in collaboration has demonstrated that clean and potable water can be produced from steep water, and that wholesome malt of excellent quality can be made from this recycled water. As water supplies become scarcer and there becomes an expectation to reduce water footprint as well as carbon footprint, the technology of ultrafiltration and reverse osmosis is likely to be deployed to the benefit of maltsters, brewers and distillers.
SWAN technology, being energy intensive, itself produces carbon emissions – so there is a choice to be made about environmental priorities. Some of the energy consumption may be offset against the energy that would have been used for waste water treatment in conventional plants.