Wine making is a relatively sustainable industry. Globally, however, it produces an estimated 13 million tonnes of waste per year, most of which is discarded. At this scale, even organic waste can unbalance the environment as decomposition can release considerable amounts of carbon dioxide.
One way to manage wine waste is to turn it into higher value products. Luckily, byproducts of winery contain a rich cocktail of chemical compounds that can be tapped for nutraceutical, health, and beauty applications.
Pomace: an overlooked feedstock
Pomace is the main byproduct of the winemaking industry, representing between a fifth to a quarter of the initial weight of the grapes. This substance is a melange of different plant parts: half skins, 25% seeds, and 25% stalks
Pomace’s biggest end use currently is further distillation into pomace spirit. Some also end up as fertiliser as grape stalks contain potassium and iron. A less common use is as a ‘feed’ for cultivating microbes that perform acid lactic production.
Despite these small-scale circular uses, large amounts of wine waste are still discarded each year. Wine waste biomass is particularly difficult to decompose because of its low pH and resistance to biological degradation.
Novel protein from winery waste
Functional food is the most promising application for the byproducts of the wine industry.
Grape pomace turns out to be a good source of polyphenols, a class of compounds that are attracting mounting attention from nutritionists.
The species mix of microbes in our gut is increasingly recognised as a key determinant of physical and mental health. Certain kinds of microorganisms are essential in producing compounds that the body needs to maintain healthy metabolisms and anti-inflammatory responses.
A healthy and diverse microbiome depends on regularly consuming foods that boost the growth of beneficial bacteria – polyphenols among them. These bacteria, in feasting on polyphenols, produce phytochemicals. These antioxidants neutralise highly reactive molecules that damage DNA inside the human body.
The specific polyphenols contained in grape seed and skins are flavanols, flavonols, proanthocyanidins (PROs), and anthocyanins. The most biochemically rich part of the grape is generally the seed. All of these compounds could be recovered from the winemaking process and introduced into food or made into supplements.
With consumers demanding palatable organic additives that provide easy ways to increase nutritional uptake, grape waste is ripe to be diverted into the food chain. One startup that is developing polyphenol-rich ingredients from wine waste is upcycler Crush Dynamics.
The Canadian company has developed a protein ingredient using pomace made through their patented fermentation process. Crucially, this biomanufacturing technique removes the bitterness from the pomace, making it a palatable food ingredient while retaining its health benefits. The company’s fermentation process has also reduced overall production cost.
Crush Dynamic has created an ingredient that has potentially wide market appeal. It does not just function as a healthy nutritional supplement but also as a multi-purpose chef’s ingredient.
It acts as a natural flavour enhancement that blocks bitter flavours, reduces the amount of salt required for flavouring, and increases umami flavours in the dish. The compounds in the ingredient also extend the shelf life of the food.
Earlier this year, Crush Dynamics announced it had developed another ingredient that allows chocolate manufacturers to reduce sugar in their products. The confectioner’s ingredient was developed in conjunction with Purdys Chocolatiers.
Crush Dynamics could widen their product range further. Its patented fermentation process can be customised to produce different kinds of end products. It can also be applied to the waste feedstock of other naturally bitter plant-based waste like cranberries, opening up a whole range of biobased feedstocks previously unsuitable for human food applications.
The company closed a $3.6 million seed round of funding in April 2022 with investors including the Western Universities Technology Innovation Fund, Women’s Equity Lab, Lumia Capital, Australia’s AgFood Opportunities Fund and Turnham Green Capital.
A circular route to gut health
The high fibre content of grape waste is another boon for gut health. Fibre is essential to human health because like polyphenols, it is another ‘prebiotic’ – a material that beneficial gut microbes feed on.
One company well-positioned to capitalise on increased consumer interest in gut health supplements is a California-based Whole Vine. It uses Chardonnay seed, stem, and skins to develop health and wellness ingredients.
The company dries and mills the grape waste into an ingredient called WellVine Coastal Chardonnay Marc, which are then blended into their alcohol-free Vine to Bar chocolate, packed in natural sweetness, fibre, and nutrients.
These wine-waste food products are the result of a decade of research by Sonomaceuticals, a wine co-product R&D company founded in 2009 by Peggy Furth and Barbara Banke, who are also behind WellVine.
Banke has a background in wine making, having co-founded Jackson Family Wines. The company has a large portfolio of wineries across the US and beyond. Waste from these wineries feeds Whole Vine’s manufacturing process.
The main compound Sonomaceuticals has investigated are oligosaccharides – a class of fibres. The company discovered Chardonnay discard contained a huge diversity of these fibres – even more than mother’s milk, which is one of the best sources of the prebiotic known. Other compounds found in WellVine’s Chardonnay marc are polyphenols, flavanols, and catechins.
Because every part of the grape is so rich in healthful biochemicals, the company uses 100% of the biomass without selectively picking off a few and leaving the rest to waste, which is the risk with some biomass upcycling models.
There could be a large market for natural fibre supplements. Studies have shown that across all age groups in the UK, average fibre intake is well below government recommendations. This reflects under-consumption of fresh fruit and vegetables, the best source of this essential macronutrient that upholds gut health, digestion, and may reduce risks of heart disease, type 2 diabetes and bowel cancer.
Collaborative research between Sonomaceuticals, LLC, the USDA Agricultural Research Service (ARS), and the University of California Davis (UC Davis) continue to uncover the wellness benefits of wine co-products.
In one research strand, Sonomaceuticals has explored the potential benefits of wine byproducts in managing diabetes and cardiovascular health. A trial examined the effects of Chardonnay grape flour and seed extract on cholesterol and insulin resistance in humans. The data suggested that insulin response in obese or overweight people could be improved by consuming these grape-based substances.
More work is needed to confirm these findings but it seems as though there are many more health-related wine products waiting to be commercialised.
Beauty applications for winery waste are also becoming popular.
Over in Britain, skincare brand Pelegrims utilised local wine waste for a limited edition antioxidant beauty range last year called 2020 Vintage collection. The facial oil, facial balm, hand cleanser, and hand pomade in 2020 Vintage drew on grape seeds, skins, and stems from wine made in Kent.
Grapey, which mainly sells online, is a skincare brand that specialises in using grape byproducts along with other organic ingredients for anti-ageing and other regenerative skincare products.
California is the booming centre of wine-waste upcycling and Good Faith is using grapeseed oil made from wine discard in its Brightening Serum + Vitamin C skin cream.
Often overlooked even by circular grape waste manufacturers are the grape leaf which, like all parts of the plant, contain polyphenols. Circumference, a New York-based sustainable beauty producer, uses grape leaves in their Active Restorative Moisturizing Cream as an ingredient that naturally reduces redness and protects the skin from environmental stressors.
The company sources their feedstock from a sustainably certified vineyard in New York state. They then use a chemical-free extraction method to concentrate the naturally occurring chemicals into their Vitis Vinifera Extract.
Vineyards to biorefineries
Vineyard and wineries present an opportunity to link up the chemicals and agricultural sector as demand for organic, health-related consumables grow. Currently, higher value uses of wine waste centre on startups that source feedstock from external wineries but more integrated supply chains could emerge if winemakers installed biorefineries on-site.
The winery biorefinery model remains mostly in its research and laboratory stages. One of the obstacles is that each grape cultivar will have differing chemical profiles meaning not all crops will be suitable for making new products. Wine makers would have to inject considerable capital into evaluating the chemical peculiarities of their plants and the specialist equipment needed to produce sidestream chemicals. So far, technical-economic feasibility evaluations are still lacking.
However, one company starting to explore this route is “I Borboni”, which produces Asprinio wine in the Campania Region in Italy. The company began using their waste to make grapeseed oil and tartrate, an acid used in non-alcoholic drinks and foods. They integrated this into their traditional production chain to increase revenue and enhance the overall environmental performance of their winery. A study showed that environmental impacts on global warming, freshwater eutrophication and mineral resource scarcity were three times lower compared to the old linear model.
Grape waste could become a brand new feedstock for the novel protein and functional ingredients category, joining fungi and pulses like soy which are already common in these industries. Unlike most of the conventional feedstocks, pomace is inherently circular, meaning a bigger industry based around winery discard could play a role in agricultural waste management.