A thousand uses for marcs

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Writer and philosopher Henry David Thoreau (1817-1862) noted that “Haste makes waste, no less in life than it does in housekeeping.” The farming and agricultural world is inseparable from the rhythms of nature, and is certainly not prone to haste, much less waste.

vinacce_mostoA classic example of this adage is represented by grape marcs, or the leftover skins and seeds from making wine. Farmers and winemakers turned what is normally considered a waste product into a resource, distilling the marcs into a what today is literally the “Italian spirit:” grappa.

Every year in Italy, 50 million hectoliters of wine and must are produced. The marcs from this process make up approximately 20% of residual solids leftover from winemaking. This means that the quantity of waste produced by the Italian wine industry is equal to about 2 million metric tons.

As we’ve already seen in a previous post, marcs must have certain characteristics to make good quality grappa—read our post to find out more. This extraordinary byproduct is not limited to making just grappa, however, but today is utilized in many industrial and artisan applications that use its special properties to create products that range from cosmetics to combustibles, from food to medicine.


Beauty cream with marc polyphenols


One of the major fields of application for marcs is in cosmetics. Marcs have been used as fundamental components in oils, face masks, purifying beauty creams, lotions, and toners for the face and body, often lauded as able to combat signs of aging in the skin. The Innuva association, which was formed recently by a research lab in Portacomaro, uses grape skin extract in their beauty products. Rich in polyphenols, grape skin extract is anti-inflammatory and protects against free radicals, helping the skin look younger.


A wine’s life doesn’t end when it is consumed, but lives on through the use of its byproducts. Nobil Bio, a biotechnology research center in Asti, is certainly aware of this, as they demonstrate in experiments that show that polyphenol extracts from marcs protect against osteoporosis and help bones to repair. Nobil Bio’s research is aimed at helping develop a granulated material that regenerates bones, plus a cosmetics line that utilizes the antioxidant and anticancer properties of these polyphenols


Marcs are also used for the production of biofuel


Marcs are also used as a font for producing ethanol, to be used on its own or in combination with other biofuels. In Italy, the project ViEnergy from Sicily obtained a fuel made from a combination of bioethanol from marcs, gasoline, and plant-based additives. The first tests to determine its advantages over petroleum were carried out in the last weeks of October 2016 in the public transport system of Marsala; emissions were proven to be less than those made from fossil fuels.


Marcs contain a high amount of polysaccharides, pectin, cellulose, and lignin, which are difficult to use in the process of making bioethanol. Research carried out in Australia in 2014 identified a mix of ascomycetous fungi (Aspergillus, Penicillum and Tricodherma) whose enzymatic activity allowed them to ferment, attacking in a solid state cellulose and lignin. This resulted in higher amounts of ethanol and other interesting byproducts for nutraceutical applications (or having high nutritional and pharmaceutical value), including xylitol, glycerol, citric acid, and malic acid.


Marc oil


The project Wine Waste, in which the Universities of Bologna, Milan, Parma, Rome Tor Vergata, and the Polytechnic Institute of Milan participated, aims to develop innovations and new technologies that are adapted to a new integrated bio-refinery chain using—you guessed it—the byproducts of winemaking. The objectives of this research project are to obtain products with high added value, such as bioactive compounds, biodegradable polymers, and nutraceutical (nutritional-pharmaceutical for health and wellbeing) and combustible compounds.

Among its most interesting research results are the extraction of bioactive compounds using a supercritical CO2 technique; the development of biopolymer plastics, such as polyhydric alkanoates (PHA); and the use of electrolysis microbial cells (MEC) to sustainably produce hydrogen—or producing an electric current via the bacterial decomposition of organic compounds, producing hydrogen or methane from organic material.


Everyone knows that vinegar comes from grapes; not very many people realize that an excellent oil can be made from marcs, too—one that is highly appreciated in the health field. Its principal nutritional characteristic is its high amount of linoleic acid, an essential omega-6 fatty acid. Our bodies cannot produce fatty acids, which are fundamental for our organs and for a healthy brain.


Colored pencils made from dregs and marcs


We saved the best for last: winemaking byproducts can be used as colored pencils. This is the ingenious idea of Federica Palazzo, owner of the winery Principe delle Baccanti in Baranello. Federica wrote a thesis and followed her own experiment that earned her the national Green Banner of the Confederation Award for Italian agriculturalists. Her idea? Extract the water from marcs and dregs and use these to create a solid material that, when formed into thin cylinders, become water-soluble, purple-colored pencils that have a similar look in their writing and drawing as charcoal. Chapeau!

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