Longevità dei vini bianchi: perseguire la qualità dalla raccolta al bicchiere
Wednesday 17 May - International Hall
Modulo gestito in collaborazione con Dal Cin
The speakers will be:
Franco Battistutta,
University of Udine
Ilaria Picco,
University of Udine
Maria Manara,
DAL CIN Gildo spa
Critical factors for the evolution of long-lived white wines
Franco Battistutta & Ilaria Picco, University of Udine
The evolution of global markets has brought about a transformation in the concepts of stability and longevity within the wine industry. In order to meet high-quality standards for several years, longevity is no longer limited to a small niche of wines, and stability has expanded beyond simple tartaric or protein stability. These concepts should be extended to almost all white wines that require good sensory evolution over an extended period of time.
From this perspective, it is useful to make a list of the main factors that influence stability and instability, as well as the production steps in which intervention can affect the evolution of wine. The main chemical activities are dependent on the interaction between the phenolic fraction, aromatic fraction, metals, and the management of redox potential.
Starting from the pre-fermentation phase, maceration, oxidizing or reducing environments, and the use of adjuvants or additives all influence the composition of the must and the evolution of the final product.
The fermentative phase normalizes redox potential but poses a series of other challenges that can lead to the development of reduction odours. Therefore, preventive or corrective action must be taken, modulated with lees, yeast derivatives, wood, or tannins.
The aging and pre-bottling periods aim to achieve overall stability of the wine. Lees, wood, yeast derivatives, tannins, and oxygen play fundamental roles in the evolution and future of the wine.
It is essential to consider temperature as well. From the mashing phase to the final glass, temperature management is often underestimated in the management of the wine’s evolution.
Longevity of white wines: the key role of yeast derivatives and tannins
Maria Manara, R&S DAL CIN Gildo spa
White wines are certainly a category highly requested by the market and their mandatory qualities are flavour intensity, freshness and cleanliness. These requirements must be maintained throughout the shelf life of the wine, until its final consumption. The pursuit of organoleptic longevity goes hand in hand with the need to ensuring a healthy product. This translates, for example, into trying to reduce the sulphite content in finished wines.
Meet these seemingly conflicting targets simultaneously, requires planning that starts with the grape harvest and continues with the treatment of the must, the management of alcoholic fermentation, up to bottling.
Yeast derivatives and tannins, individually or in combination, are valuable allies in achieving these goals.
Yeast derivatives are among the most interesting tools at the winemaker’s disposal to ensure the correct evolution of white wines. Depending on the yeast of origin and the production systems employed, derivatives with different characteristics can be obtained and thus exploited to achieve different objectives. Harmony Vitality, a yeast derivative to be used during ageing and storage, thanks to the presence of GSH and reducing peptides, protects the wine from oxidation, removes certain sulphur compounds, potentially oxidisable polyphenols, and ensures wine longevity by preventing browning and pinking.
Tannins represent a second family of effective and diversified means; their use makes it possible to achieve specific objectives such as protection from oxygen, capture of volatile thiols, chelation of metals, while respecting or improving the taste balance of the wine.
The application of innovative analytical techniques, including cyclic voltammetry, has made it possible to identify the correct tannin to use in the different stages of winemaking, from harvesting to ageing, to bottling. Top Tan AR, Infinity Vert and Tanniblanc can be used both during ageing as well as in pre-bottling.
Many observations from our studies on the longevity of white wines are also reflected in the production of rosé wines. We have specific works in progress on this delicate type of wine, with particular focus of the colour hue preservation.
