Raise a Glass to Neat Ideas for More Eco-Friendly Whisky

The Scottish whisky industry is starting to make the most of its industrial by-product to produce energy from anaerobic digestion and biomass
May 7, 2015 10:30 AM ET

Originally posted on The Guardian

It may have a heritage dating back centuries, but in the last five years the Scottish whisky industry has undergone something of an energy revolution. 

In 2009, the Scotch Whisky Association (SWA) launched an Industry Environmental Strategy for its membership of 101 malt and seven grain distilleries, accounting for over 90% of the industry. Alongside commitments on water reduction and packaging, it set a target of 20% energy from renewable sources by 2020 and 80% by 2050. At the time of the strategy launch, non-fossil fuel energy use in the industry was at 3% and by 2012 it had reached 16%. 

The SWA is currently crunching the latest figures, but it’s possibile that the 2020 target will be met ahead of time. So, how is it making this progress?

Replacing fossil fuels

The distilling process is energy intensive. The main energy requirement (79%) goes into the heat required (pdf) to fire the giant stills which drive the distillation process, traditionally done by burning fossil fuels.

However, the industry has now discovered an energy source much closer to home, namely “draff” – the spent grain left over from distilling. Using draff, energy can be produced either though biomass combustion by burning dried waste draff, or through anaerobic digestion (AD), whereby draff is mixed with pot ale (the yeast and protein-rich liquid created during distillation) to produce methane.

Anaerobic digestion

Julie Hesketh-Laird, director of operational and technical affairs at SWA, says that AD, the process by which organic matter is broken down to produce biogas and biofertiliser, has only been looked at properly in Scotch whisky production over the last four to five years. “The batch nature of malt distilling has made it difficult, but increasingly companies have had success.”

Iain Lochhead, operations director at five distillery sites for Bacardi-owned John Dewar & Sons, says that a wood-pellet boiler at its Aberfeldy site has been operational since the end of 2014. Bacardi estimates that the project could reduce the distillery’s carbon footprint by up to 90%.

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