The pressed ‘marc’ – after fermentation – before heading on its way to the distillery. This article was assembled with some input from Claire Pernet of the BIVB; she’s responsible for ‘Sustainable Development.’
Anyone who’s been part of a harvest probably thinks from time to time – ‘What do they do with all the waste?’
Waste? Well, yes. There are piles and piles of stems from the destemming machine, not to mention all the discarded grapes that were, for various reasons, deemed not good enough to put into a fermentation tank. But that’s less than the half of it…
Only a couple of weeks later comes ‘decuvage’ – the emptying of the fermentation tanks, the loading (digging out!) of the solid but very wet stems and grapes/skins/pips into presses to extract the last useful juice. The result of this is literally thousands of tons of solid waste material, but let’s not also forget the lees and ‘bourbe’ (wine irredeemably clouded by the dregs of yeast) – effectively, this is all ‘industrial waste’ – but where does it all go?
The first material discarded from the process – pre-fermentation – is largely destined to be sent for composting. Some Biodynamic producers, for instance, holding onto their waste to do their own composting – in this way they can be 100% happy about the provenance of the compost spread in their vineyards.
Post fermentation waste is much more highly regulated because the pressed waste material still contains alcohol from the fermentation. There are often particular organisations, or collectives by village, that arrange the collection and subsequent distillation by mobile distillation wagons, or, as is becoming more and more common, the waste is transported to larger distillation facilities in (for instance) the Beaujolais or Mâconnais. Producers often see this as a ‘tax’ because the resulting alcohol belongs to the French government. The material is, of-course, weighed when collected from a producer, and if the weight seems much less than the customs expect, there is always the possibility of ‘a visit!’
There are roughly 50-such distilleries spread across France, each year collecting about 850,000 tonnes of solid materials and 1.4 million hectolitres of lees and bourbes! Burgundy, even when combined with Beaujolais and Jura accounts for ‘just’ 6% of this total.
But like any aspect of life, one person’s waste is often another person’s opportunity. There is also value to be unlocked from this waste. Whilst almost all of the post-distilled ‘solids’ are destined to be ‘biomass’ for energy production there are projects and experimentation afoot to try to unlock further value: Ethanol, methane, grapeseed-oil, the extraction of phenolics and anthocyanins for cosmetics (anti-aging creams) and colourings, even additives for animal feeds – these are all referred to as the ‘sub-products’ of vinification. It might actually be better to refer to these as the potential sub-products of vinification, as it is currently a vanishingly small percentage that is utilised in this way, but, projects often together with other ‘agricultural waste’ producers, continue the search for new possibilities.
And, as they say where I come from, Where there’s muck, there’s brass. The search for ‘brass’ continues…