To create innovative manufacturing processes that can generate efficient and sustainable production, at the same time, capable of further enhancing the sensory characteristics of wines. For wineries, the quest for excellence is continuous, and achieving it comes through research and experimentation. The application of gases in enology and the use of new technologies in grape processing permit not only to overcome critical issues at the most delicate stages, but also to enhance the value of the final product.This is demonstrated by the experience of Araldica Castelvero, Winery Il Cascinone, winners of the second edition of the SIAD International Award, an initiative conceived by the industrial group, in collaboration with Oicce (Interprofessional Organization for the Communication of Knowledge in Oenology) to stimulate innovation in the use of technical gases in oenology.
The team of experts pioneered “a new cryomaceration application solution with the intention of extracting more and preserving from oxidation the component aromatic primary grape by short cold maceration of the crushed grapes,” explains Alberto Caudana, lecturer in the Food Technology degree program at the University of Turin, coordinator of the working group consisting of. Carlo Manera, enologist and technical director of the Araldica – Castelvero Winery, from Gaetano Pio Liscio and Camilla De Paolis, oenologists from the University of Turin’s Experimental Winery, and Martina Bordellini, thesis student of the internateneo Master’s degree program in Viticulture and Enological Sciences.
Dr. Caudana, what does your project “Enhancement of Cortese-based wines by pre-fermentation maceration with cryogenic gas” consist of?
The experimentation focused on Cortese-based white wines. Precisely because of the peculiarities of these grapes and their processing, protection from oxidation is essential, and this necessarily involves the appropriate use of inert gas protection from the time the grapes are crushed.
In what context did you operate?
The trial was conducted by Araldica Castelvero, Winery Il Cascinone. The Cortese grape variety in Piedmont represents 3,000 cultivated hectares, one DOCG and four DOCs, for just under 100,000 hectoliters of bottled wine in 2019, but above all a long and noble tradition documented since the 17th century. A likely indigenous white grape vine, Cortese-also known by the dialectal terms Corteis, Courteis and Courteisa-adapts to even very different soils, as long as they are free of waterlogging, but prefers soils rich in sediment and not too fertile. It is grown in the Piedmont hills south of Alessandria, from Ovada to the Tortonese Hills, in the province of Asti on the right bank of the Tanaro River, and in Cuneo in the lower Belbo Valley. High acidity and moderate alcohol content are the main characteristics of Cortese grapes, which can have very different profiles depending on the growing environment and agronomic techniques adopted. This is the reason why it is expressed in different appellations of origin: Gavi or Cortese di Gavi DOCG, Colli Tortonesi Cortese DOC, Cortese dell’Alto Monferrato DOC, Piemonte Cortese DOC (1994), Monferrato Casalese Cortese DOC (1994). Also worth mentioning among the expressions of the grape variety is the “Marengo” version, newly introduced in the Piedmont DOC Cortese specification, which calls for sparkling or semi-sparkling wines made from Cortese grapes.
What is the prevailing production model?
It is that of a young, fruity white wine with a straw-yellow color, marked by aromas of fermentation origin, endowed with flavor freshness and savoriness consequent to the rich endowment of fixed acidity. With a view to producing more sustainable wines with a reduced sulfite content, we found the need to intervene in this production model in order to overcome some critical issues related to the olfactory component that relies mainly on fermentation aromas that do not enhance the potential of the grape variety.
What model did you develop in the course of the experimentation?
We tried to develop a winemaking model capable of extracting more of the primary aromatic component of the grape by means of a cold maceration of short duration but effective, immediately after crushing, exploiting time in the press to achieve a release of soluble compounds into the must, limiting the passage of phenolic substances. Avoiding maceration of the grapes in tanks accomplishes an additional result: avoiding difficult and costly transfers of the crushed grapes.
In line with the aims of the SIAD Prize, launched with the aim of stimulating research in enology through the innovative use of gases, you have exploited the characteristics of CO2. How?
The use of carbon dioxide, dispensed on the crush through the innovative Kryos system, allows for a rapid cooling, a slightly cauterizing action of the peel tissues capable of promoting divestment, a limitation of the presence of oxygen and, as a result, a strong Slowing down of oxidase activities. The must obtained from the pressing is cold and does not need to be further cooled for subsequent sfecciante sedimentation. This aspect represents an additional element of energy sustainability.
The experimentation confirmed the goodness of using carbon dioxide in the processing of cortese-based grapes, but not only that. Is that so?
Yes, in fact other varieties can also benefit from these effects so trials are underway on aromatic varieties such as the Brachetto, the Sauvignon blanc and on Nebbiolo, where the lowering temperature conditions and low oxygen presence could favor The extraction and protection of the first anthocyanin fractions leaking from the skins during mashing. Initial tests show an effective and sudden lowering of must temperature favoring the prefermentative extraction stages with a increase in the dye fraction and greater protection of the must from oxidation immediately after crushing, a particularly critical time since there is still no carbon dioxide produced by fermentation.
Farms, particularly wineries, are facing several challenges, what will be the main ones in the coming years?
Wine producers have long been facing several challenges, and many fronts are open, starting with reducing the use of sulfites and the environmental impact of vine disease defense. Environmental sustainability is a top priority, which is why we are constantly working on implementing solutions in order to curb the energy consumption of wineries and identifying new techniques for reducing and reusing water used in the production process, as well as recovering energy from oenological by-products. Last but not least, the characteristics of our indigenous ampelographic heritage must be maximized and expressed to the fullest, a richness that makes it possible to diversify production and attract an increasingly curious and attentive consumer. This requires expanding our knowledge of rare grape varieties and developing ad hoc winemaking models to enhance their characteristics.
What, in your opinion, is the key, in order to overcome these challenges?
Undoubtedly, working in a network, adopting a multidisciplinary approach, will make it possible to achieve great results in both viticulture and oenology in the coming years.
What role do gases play in fostering innovation in enology?
The use of gases is key to fostering innovative wine production. In particular, it is essential in order to protect against oxidation at all stages of production from must to bottling. As our research shows, gases are indispensable for preserving the sensory characteristics of wines and limiting the use of sulfur dioxide as much as possible. In some cases, they can also facilitate the prefermentative extraction of the aromatic and phenolic components of the grape, allowing for greater characterization of the grape variety of origin.
Ph. Copyright Edition OICCE 2021.
