Using pomace, grape seeds, stems, leaves and winery wastewater for a true circular, industrial-scale bioeconomy helps create opportunities to make the sector’s economy more sustainable and safeguard natural resources
By Emanuele Bompan – director of Renewable Matter.
From grapes we naturally derive vinegar; it is the art of man that turns it into wine. But it is the magic of chemistry that allows innumerable by-products to be derived from wine production, from pomace for distillates to polyphenols for cosmetics, substances such as tartaric acid or dyes, and even energy production, with biomethane and bioethanol used to power agricultural vehicles or fed into the methane grid.
The circular economy of grapes is ancient. The first upcycling of grape waste dates back to the 6th century AD. In fact, historian Luigi Papo traces the first production of grappa in Friuli-Venezia Giulia back to 511 AD by the Burgundians, who from nearby Austria, during a brief installation in Cividale, applied their own techniques used in distillation from apple cider to distillation from pomace, thus obtaining the well-known alcohol.
More than a thousand years would pass before the product became modern. The birth of Distilleria Nardini, in Bassano del Grappa in 1779 brought about a real revolution and marked the beginning of modern distillation in Italy, through the introduction of the “steam” distillation method. Bortolo Nardini is in fact the oldest distillery in Italy, thus boasting the title of Italy’s first grappa. Since then, grappa-along with other distillates from wine such as cognac, armagnac, pisco and brandy, from pomace such as orujo, from must (already used in many sweets such as mostaccioli) such as acquavite-has conquered the market and the tastes of many peoples around the world.
The importance of upcycling even for smaller companies
For the past 20 years or so, however, we have been thinking, as in every agricultural supply chain, about how to use all production waste: pomace, grape seeds, stems, leaves and cellar effluent for a true circular, industrial-scale bioeconomy. Having industrial symbiosis in the wine sector helps create opportunities to make the sector’s economy more sustainable and safeguard natural resources.
There are many companies and cooperatives that have developed technologies capable of making products and chemical components used in a wide range of sectors, from food to cosmetics, from pharmaceuticals to construction. But still the presence of so many small to medium-sized farms (between five thousand and one hundred thousand bottles of production) makes the creation of a circular economy supply chain for grapes complex, with millions of tons of waste being dispersed, or at most used (in excess) as soil conditioner.
Alberto Di Stefano runs a small natural wine cellar in the hills of Bologna, farm L’Upupa. “All the clippings and pomace,” he explains, “today go as a soil conditioner on the land, but it would be interesting to have supply chains for small producers as well to make more and more value out of production waste. It could lend a hand to the year-end budget.” In the meantime, those who are moving forward are large companies and cooperatives, or where the industry teams up and creates a waste marketplace that is horizontal and well-organized.
The eno-bioeconomy in France
In France, the world’s leading wine producer, there are numerous initiatives to recover biomass and waste from classic distillation. To help Val de Loire operators choose the most appropriate recovery methods, the IFV – Institut Français de la Vigne et du Vin, and InterLoire, the Loire Valley consortium, have produced the first Atlas of Plant Biomass – Val de Loire Basin. This tool identifies and locates both the resource and recovery facilities, both qualitatively and quantitatively, in map form and lists local actors in this sector.
Champagne is also doing its part: “By recovering residues and sediments from the winemaking process, new products can be generated, including bioethanol, potable alcohol, grape seed oil, fertilizer, compost and animal feed. As a result, about 110,000 tons of wine by-products are recovered in distilleries every year,” the consortium’s official website explains. Thus, each year, 80,000 tons of vine shoots provide the organic matter needed for soil life.
Of course, French wine overproduction is certainly not circular. Last year 200 million was spent to destroy surplus wine and subsidize farmers to turn wine into alcohol for various uses. An overproduction due to the reduction in the quantities of wine consumed globally (we drink less, better quality) that will result in a necessary reduction in the area planted with vines by 750,000 hectares.
The circular economy of grapes in the U.S.
Much work has been done in the U.S. on alternative distillations, but still little in the circular grape economy. Tom Gamble, of the Gamble Family Vineyards of Napa, was one of the first in the United States to try to use grape waste, using the flash détente process, which extracts color and flavor from grapes by heating them in a device that resembles a large pressure cooker. The company has thus been able to use partially ripe fruit (that would otherwise have been discarded) and make wine from it. Their first attempt to use the process made a product good enough to be sold in the bulk market.
At the winery Villicana Winery and Vineyard in Paso Robles, California, Alex Villicana was one of the first to instead recover the juice that is left on the skins. It is common for winemakers to take only a portion of the pressings into fermentation tanks and throw away the rest. “Because I grow the vineyard myself, this [spreco] used to drive me crazy,” Villicana says. “I was seeing 30-40% of my work go up in smoke.” The situation was doubly frustrating because “in trying to make the best wine, we get out what is probably the best juice before fermentation.” Initially Villicana tried using the juice for brandy, but it was too low in acid. Then he came across research that wine grapes could be made into vodka. Two years later, in 2011, he opened the Re:Find distillery with the goal of using 100 percent of the grapes he grows. Today Re:Find produces numerous spirits, including vodka, whiskey and gin, and works with about 30,000 gallons of liquid per year, which translates to about 200 tons of grapes.
Lacking, however, are companies that truly recover everything across the Altantic, where the circular economy is still a niche discourse. One exception is Sonomaceuticals, a company founded by Peggy Furth, former owner of Chalk Hill Estate Vineyards, and Barbara Banke, president of Jackson Family Wines, which in California’s Sonoma Valley has begun extracting anti-aging compounds, such as anthocyanins, from dried Chardonnay grape skins and seeds to improve liver and cardiovascular health. A unique case, so far.
The case of Caviro Extra, one of the leaders of the Italian circular economy
Italy, on the other hand, has much to teach. The circular bioeconomy of grapes already has significant dimensions and wide margins for growth. It is estimated that in Italy 50 million hectoliters of wine (80 percent of vine production becomes the noble beverage, according to ISTAT data) and must are produced each year, of which, approximately 20 percent is composed of the solid residues of winemaking. Data in hand, the amount of waste from the Italian wine industry can be estimated at about 2 million tons (of which more than 1 million tons is pomace alone). A treasure trove of matter that cannot be wasted.
With 28 social wineries and 11,000 winemakers present in seven regions of Italy, tending 35,200 hectares of vineyards, Caviro, an agricultural cooperative based in Faenza, represents the largest production chain in the wine sector in Italy. Today the group can boast from historic brick brands (Tavernello and Castellino) to premium products such as Amarone from Gerardo Cesari S.p.A. or Chianti Cantine Leonardo Da Vinci. With sales of 428 million euros in 2023, Caviro exports a wide range of Italian wines to more than 70 countries and holds the top Italian brand in Italy. On the strength of the company’s large volumes, through its subsidiary Caviro Extra and its joint venture with the Hera Group, Enomondo, it succeeds in expressing a full circular economy model, renamed “From Vine to Vine.”
The Romagna-based company aims to recover through every waste (dregs and marc) of the wine production process new value and answers for production needs. Some by-products are transformed into new ingredients and products for pharmaceutical and agro-industrial companies. With anaerobic digestion of wastewater and the production of biofuel from mowings (also collected from prunings from around the area with the support of the company Herambiente), electricity and thermal energy are produced.
All this means that today the entire Caviro Group and all its companies, are totally self-sufficient for their energy needs, and more than 50 percent of the renewable energy production generated within the group is then sold to national grids for the benefit of the community. The biogas produced consists of about 70% methane and about 30% carbon dioxide, which is captured, after a process of compression and liquefaction, and released into the food market (carbonated beverages) as a substitute for that of mineral origin.
According to data obtained from the sustainability report, Caviro Extra converts about 127,000 tons of pomace and lees into noble products such as alcohol, tartaric acid (natural preservative), enocyanine (natural food coloring) and grape seeds for polyphenols, which are then sold to companies in various sectors. 266,000 tons of material are sent to anaerobic digestion, 46,000 tons to compost. Inside the Caviro Extra plant, in Faenza, 50,000 tons of natural fertilizer are also produced: composted soil improver from agribusiness chain waste (ACFA). To really close the loop: the residue from all processing that is taken for disposal turns out to be less than 1 percent of what is received.
Prosecco, the giant of circular bubbles?
In 2023, Prosecco DOC production reached more than 616 million bottles, registering a 3.5 percent decrease from the previous year, when 638.6 million bottles were bottled. Conegliano Valdobbiadene DOCG saw a 10 percent drop in production, with 92.5 million bottles produced in 2023 compared to 102.7 million the previous year. But despite this, it remains one of the leading appellations in terms of quantity, with nearly 30,000 hectares of vineyards across 9 provinces in Veneto and Friuli-Venezia Giulia distributed among 12,000 farms.
“There are numerous initiatives that wineries in the sector are adopting,” Giancarlo Guidolin, president of the Prosecco DOC protection consortium, tells the author. “Pruning residues are shredded directly in the vineyard so that, as they degrade, they can supplement the soil with organic matter. The pruning residues are either turned into compost or used in the production of energy-the destination in the distillery. Grape seeds, pomace and lees are in high demand in the cosmetics industry.” Like the Villa Sandi winery, which has its own “98 percent natural” cosmetic line offering skincare and beauty routines. “And let’s not forget the recovery of packaging, especially glass, and even those who reuse washing water, as in the case of Cantine Maschio,” he adds.
“Figuring out what destinations the waste will have, however, is not easy, as we are talking about 60,000 tons of residues for pruning alone. In 2023, the Consortium with the University of Padua presented a project on MASAF’s Supply Chain Contracts funding line, aimed at the economic and environmental evaluation of circular technologies,” Guidolin explains. The activities included the economic analysis of the extraction processes of valuable substances that can be obtained from pruning residues (stilbenes-viniferin and resveratrol-substances that can be used for antifungal treatments on grapevines, and biochar, a soil conditioner derived from the pyrolyzation of the residue) and from the by-products of winemaking (tannins and proteins from seeds; polyphenols, oligo- and polysaccharides from skins and lees; biochar from the pyrolyzation of residues from different extractions).
“This general analysis involves: assessing the economic value of each of the aforementioned products; evaluating the costs of the extraction processes, identifying fixed and variable costs related to different technological solutions and operational dimensions of the processes; configuring logistical solutions for the collection of materials and identifying cost parameters,” continues the president of the Prosecco Consortium. The project will have to seek optimal operating conditions, referring specifically to the Prosecco DOC supply chain, creating a perfect industrial symbiosis between wineries and waste processors and contributing to the increased absorption of CO₂ by the soil. But above all, contributing to the reduction of fertilizer consumption, which has long been one of the most urgent problems to protect the biodiversity of the territory.
The virtuous world of grappa
One of the forerunners of the circular grape economy, it has been said, were grappa producers, such as Nardini, Nonino, Marzardro, Segnana, Poli and many others. “Nonino distills 90 percent of pomace from Friuli-Venezia Giulia,” explained Antonella Nonino, of the eponymous distillery in Friuli, which revolutionized the entire industry in 1973 by bringing grappa on par with the great international spirits with the creation of the single varietal.
“Vinacce purchased from selected suppliers with whom we have established relationships, such as Pinot Grigio, Pinot Bianco, Friulano, Chardonnay, Ribolla Gialla, Sauvignon, Tarminer, Merlot, Glera (for Prosecco) Schioppettino, Refosco dal peduncolo Rosso, Cabernet, Verduzzo and Picolit. And some varieties such as Moscato and Malvasia that we buy in the Broni area in Antico Piremonte. The pomace from which Grappa Nonino is made, once distilled-100 percent by artisanal method in a very short time-is sent to feed mills for the production of animal feed, used as fertilizer for nurseries, used to obtain seed oil-which has highly valued nutritional characteristics-from grape seeds, and finally destined for biogas production.”
In 2023, the company presented together with Green Spot Technology and ReGeneration Hub Friuli the circular economy project: Nonino Flour – Green Spot. “Ninna Granucci, a researcher of Italian-Brazilian origin, from the startup Green Spot, who is in love with Grappa Nonino, has created an innovative gluten-free flour from pomace thanks to a new fermentation process-which has earned her five patents-succeeding in obtaining a flour that retains the important nutritional properties of pomace while harmonizing the flavor of Nonino white and red grape pomace,” explains Antonella Nonino. The upcycling process has the advantage of obtaining not only a product of high nutritional value, but also an increase in yield and a reduction in production and environmental costs with lower energy consumption.
Biomethane production and the Bonollo case
In the neighboring Veneto region, a biomethane production plant connected directly to the grid of Italgas, a leading company in the sector, was inaugurated on April 12, 2023, at the Distillerie Bonollo Umberto plant in Conselve (Padua). Invested 2 million euros for the plant plus 500,000 for the connection, to sell 2.5 million cubic meters of gas per year to the grid, which corresponds to more than 10,000 cubic meters per day.
“Every cubic meter of biomethane obtained here,” says Elvio Bonollo, owner of the distillery, “is one more fruit of the generosity of the vine, in a supply chain that after the wine is obtained in the cellar finds in Bonollo the highest expression in terms of circular economy through the extraction and valorization of precious by-products in a zero-waste logic. Giuseppe Bonollo, who 115 years ago started our distillery business and who passed on to us the precious value of being ahead of the times through innovation, would be proud to know that the family business, in addition to giving the best grappa in the world, contributes to the decarbonization of energy consumption by feeding precious non-fossil gasinto the grid.”
Among Bonollo’s circular economy initiatives to valorize grape pomace, after the creation of high quality spirits such as the well-known OF Amarone, there is still much useful and valuable to be obtained. For example, the extraction of calcium tartrate, a substance used in oenology, the food industry and the pharmaceutical sector; ground grape skins, rich in cellulose and nutritional substances, used in the production of animal feed and in part to boiler feed; grape seedoil from which an edible oil with dietary characteristics is obtained. Finally, polyphenols, natural substances of high value that have antioxidant properties and are used in the food supplement sector (such as the product Ecovitis) to support the regular function of the cardiovascular system and the functionality of the microcirculation, are extracted from the exhausted pomace using an innovative process patented by Bonollo.
A cycle that starts from the grape and returns to the grape, after man has benefited at every level, whether for the warmth of heating, the pleasure of schnapps and winemaking, or the benefit of oenocosmetics.
