A new way has been discovered to get flavours and perfumes for food and cosmetics out of the pulp left after grapes have been pressed to make wine. Currently, the pulp, called marc in winemaking, is mainly viewed as a waste product. Some winemakers pay to have it taken away by specialist industrial alcohol-makers, who extract the remaining alcohol from it. Others use a complicated process to make compost out of the pulp, which is often too acidic to break down naturally. In some regions, the marc is spread on the ground as a mulch.
Giving new flavourful life to wine waste
Alain Etiévant, founder and managing director of Lyon-based research and development company Atelier du Fruit, said: “Our researcher Maxime Haure, who is working towards a doctorate, has found a way, using fermentation, to unlock the flavours which are normally hidden in the marc. We have known for years that 80% of the flavours in fruit are actually blocked and hidden from us but this process, which changes sugars, means we can then taste and smell them.”
According to how the process is tweaked, the extra flavours and perfumes can be very fruity, jammy or flowery. “There has been a move away from the use of synthetic flavours made in laboratories, which is where most flavouring in processed food and perfumes in cosmetics come from,” he said. “We are very excited that we have found a way where our clients, large companies, can say they are using natural products as ingredients.”
Investing in zero-waste practices
He said there has been most interest in industrialising the process from cosmetics companies. “The investment for an industrial unit is quite large – you need a closed fermentation vessel where you can control the temperature, oxygen levels and other things and then extract the molecules you want,” he said. “Margins in the food industry are much tighter than in cosmetics and so it is there that the first industrial units will be put in place, probably in the next year or two.”
As well as grape pulp, other waste material, such as tomato skins from canning factories or apple peel from factories making fruit purées, can be subject to the same process. “You don’t think of tomato skins as having wonderful smells and flavours locked away in them, but they do – you just have to free them,” said Mr Etiévant. The residue left after the fermentation process can be used as a compost.