Champagne-making leftovers could be used as insulating material for buildings

Leftovers from champagne-making could serve the construction industry in the form of a biosourced insulating material. Photo: AFP

From fertiliser to bioethanol or even cattle feed, there are already ways to upcycle the leftover grape residues from the production of champagne, known in the business as the "aignes".

But a new way to potentially reduce the carbon footprint of champagne production – while also reducing that of the building sector – is now being proposed.

France's champagne producers have set themselves the goal of reducing the sector's carbon footprint by 75% by 2050. To help achieve this, the industry has joined forces with ADEME, France's agency for ecological transition, to implement the "champagne carbon audit", which allows 30 recently installed pilot vineyards to benefit from a personalised environmental audit. This includes soil analysis as well as agri-educational advice.

According to the Comité Champagne trade association, the sector has already managed to reduce its greenhouse gas emissions by 14% over the last 15 years.

But the task is colossal: the interprofessional body estimates that some 10,000 tonnes of waste is generated each year by the production of the legendary fizz.

Among the many avenues of exploration in this quest for transformation is the establishment of circular economy based on the recovery and reuse of the by-products of wine-making. This can be sediment, lees or even grape pomace. Ways have already been found to upcycle this waste into grape seed oil, bioethanol, or even cattle feed.

Similarly, vine shoots – the wood recovered during the pruning of the vines – can be reintegrated into the soil. Now, new research could make it possible to kill two birds with one stone by reusing grape pomace to make an insulating material for buildings, to be used instead of fibreglass or polystyrene.

In champagne production, this leftover grape waste is known as the "aignes", and includes residues such as the stalks – the branches on which the grapes hang – as well as the pips or the skin of the grapes.

This is exactly the same material that is sent to distilleries to produce a drink called marc de champagne, a kind of brandy that's aged in oak barrels to obtain a rich and intense beverage.

At the University of Reims Champagne-Ardenne, a doctoral student called Celine Badouard is interested in this byproduct because its quantities can be enormous in vineyards.

According to the researcher's thesis presentation, champagne generates nearly 100,000 tonnes of it per year. In comparison, the total quantity produced throughout all of France is 850,000 tonnes.

The result of this research takes the form of sheets or slabs of aignes that are assembled by an adhesive in turn made from grape pomace. Not only do they provide a new solution for recycling waste from grape pressing in champagne production, but they also provide a way to reduce greenhouse gas emissions from the construction sector.

According to this thesis, the construction industry is the most energy-consuming sector in the European Union (31%), and is responsible for 23% of the greenhouse gas emissions generated by this same geographical area. – AFP Relaxnews