Terroir 1996 banner
IVES 9 IVES Conference Series 9 La vinificación de las uvas aromáticas: Moscateles y Malvasías

La vinificación de las uvas aromáticas: Moscateles y Malvasías

Abstract

Las uvas aromáticas se pueden dividir en dos clases, Moscateles y Malvasías, dependiendo del hecho de que el linalol o el geraniol, respectivamente, sean los alcoholes terpénicos monohidroxilados que predominan en el jugo de la uva. Dentro de cada clase existen numerosas subclases que se diferencian por las relaciones entre los otros alcoholes terpénicos mono y dihidroxilados, en forma libre y glicosilada. Otra diferencia entre los Moscateles y las Malvasías es la cantidad de compuestos terpénicos libres del mosto, (los terpenos del hollejo, en las dos clases, se encuentran casi en su totalidad como formas glicosiladas) que puede ser alto como en el caso del Moscatel (linalol, óxido trans piránico del linalol, 2,6-dimetil-3,7-octadien-2,6-diol) o mas bién bajo como en el caso de las Malvasías (geraniol, 2,6-dimetil-3,7-octadien-2,6-diol), mientras que en los hollejos es una característica común a las dos clases la presencia de elevadas cantidades de nerol y de geraniol en forma glicosilada. La composición terpénica de las dos variedades condiciona, además del aroma del vino final, la tecnología de producción.En Italia con el “Moscato bianco” y con las Malvasías (“Malvasia di Casorzo”, “Malvasia di Castelnuovo don Bosco”, esta última en muchos aspectos parecida a los Moscateles, “Brachetto d’Acqui”, que son todas variedades tintas) se preparan dos tipos de vino: uno espumoso y uno no espumoso. El primero se caracteriza por un contenido alcohólico de aproximadamente un 7%y una concentración de azúcares de aproximadamente 70 g/L y el segundo por un grado alcohólico del 5 % y una cantidad de azúcares variable dependiendo de los gustos del productor.En la vinificación del “Moscato bianco” se utiliza solo el mosto (una eventual criomaceración no conlleva un aumento sensible en compuestos terpénicos), que es rico de linalol que no resulta ni absorbido ni metabolizado por las levaduras, mientras que en el caso de las Malvasías tintas, para cuya vinificación se utilizan también los hollejos, el geraniol, practicamente el único alcohol terpénico monohidroxilado presente en el mosto, es metabolizado parcialmente por las levaduras y en parte reducido a citronellol y estos dos compuestos, además del nerol, son transformados en derivados acetilados. Además, a causa de las elevadas cantidades de glucosa que se encuentran en el mosto durante toda la fase de preparación de los vinos de estas variedades, los enzimas glicosidásicos, del mosto o de las levaduras, no pueden transformar en los respectivos aglicones los glicósidos del nerol y del geraniol presentes en el mosto, que quedan, por lo tanto, en forma glicosilada, es decir, no aromática, en el vino final. Las técnicas tradicionales de vinificación establecen, para la extracción del color y de los compuestos terpénicos de los hollejos de las Malvasías tintas, continuos remontados cuando la fermentación todavía no ha empezado, o una fermentación parcial en presencia de los hollejos. Estas dos técnicas son insuficientes sea para extraer la gran cantidad de glicósidos del nerol y del geraniol de los hollejos, sea para hidrolizar los glicósidos terpénicos. En este trabajo se presenta una nueva técnica de vinificación, que favorece la extracción y la hidrólisis de los compuestos terpénicos de los hollejos de las Malvasías tintas y que incrementa sensiblemente la intensidad del aroma y la calidad de los vinos que se obtienen con esta variedad.

DOI:

Publication date: February 24, 2022

Issue: Terroir 2000 

Type: Article

Authors

Rocco Di Stefano*, Emilia García Moruno* and Monica Ribaldone**

*Istituto Sperimentale per l’Enologia, via P. Micca 35 — 14100 Asti (Italia)
**Consorzio per la tutela del Brachetto

Tags

IVES Conference Series | Terroir 2000

Citation

Related articles…

Spatial determination of areas in the Western Balkans region favorable for organic production

In problematic conditions for production of grapes and wine caused by the COVID-19 pandemic and the resulting occurrence of wine surpluses, producers are increasingly turning to the innovative viticulture and winemaking of products that are more appealing to the market and the consumers. On the other hand, consumption of the food safety or organic products, and therefore of organic grapes and wine, is increasingly common in the world, in particular in Europe. The Regional Rural Development Standing Working Group (SWG RRD), as a regional intergovernmental organization gathers actors in the viticulture and winemaking sector from states and territories of the Western Balkans (South-East Europe) in the Expert Working Group for Wine, with the aim of improving viticulture and winemaking in this region through joint activities. In accordance with the aforementioned, the SWG RRD is working on advancing organic production of grapes and wine, and on recognition of specificities of the terroir of wine-growing areas in Western Balkans. In addition, as part of the project “Facilitation of Exchange and Advice on Wine Regulations in Western Balkan Countries” helmed by the German Federal Ministry of Food and Agriculture, in addition to harmonization of relevant legislation with EU regulations, efforts are being invested towards recognition of organic wines. Within activities and project implemented by this organization, expert analyses and scientific research of the terroir of Western Balkans were carried out, and some of the results are presented in this paper.

Impact of yeast derivatives to increase the phenolic maturity and aroma intensity of wine

Using viticultural and enological techniques to increase aromatics in white wine is a prized yet challenging technique for commercial wine producers. Equally difficult are challenges encountered in hastening phenolic maturity and thereby increasing color intensity in red wines. The ability to alter organoleptic and visual properties of wines plays a decisive role in vintages in which grapes are not able to reach full maturity, which is seen increasingly more often as a result of climate change. A new, yeast-based product on the viticultural market may give the opportunity to increase sensory properties of finished wines. Manufacturer packaging claims these yeast derivatives intensify wine aromas of white grape varieties, as well as improve phenolic ripeness of red varieties, but the effects of this application have been little researched until now. The current study applied the yeast derivative, according to the manufacture’s instructions, to the leaves of both neutral and aromatic white wine varieties, as well as on structured red wine varieties. Chemical parameters and volatile aromatics were analyzed in grape musts and finished wines, and all wines were subjected to sensory analysis by a tasting panel. Collective results of all analyses showed that the application of the yeast derivative in the vineyard showed no effect across all varieties examined, and did not intensify white wine aromatics, nor improve phenolic ripeness and color intensity in red wine.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

Effect of partial net shading on the temperature and radiation in the grapevine canopy, consequences on the grape quality of cv. Gros Manseng in PDO Pacherenc-du-vic-Bilh

As elsewhere, southwestern France vineyards face more recurrent summer heat waves these last years. Among the possibilities of adaptation to this climate changing parameter, the use of net shading is a technique that allow for limiting canopy exposure to radiations. In this trial, we tested net shading installed on one face of the canopy, on a north-south row-oriented plot of cv. Gros Manseng trained on VSP system in the PDO Pacherenc-du-Vic-Bilh. The purpose was to characterize the effects on the ambient canopy temperatures and radiations during the season and to observe the consequences on the composition of grapes and wines. Two sorts of net were used with two levels of obstruction (50% and 75%) of the photosynthesis active radiation (PAR). They have been installed on the west side of the canopy and compared to a netless control. Temperature and PAR sensors registered hourly data during the season. On specific summer day (hot and sunny) manual measurements took also place on bunches (temperature) and in different spots of the canopy (PAR). The results showed that, on clear days, the radiation is lowered by the shade nets respecting the supplier criteria. The effects on the ambient canopy temperature were inconstant on this plot when we observed the data from the global period of shading between fruit set and harvest. However, during hot days (>30°C), the temperature in the canopy was reduced during afternoon and the temperature of the bunch surface was reduced as well comparing to the control. A decrease of the maturity parameters of the berries, sugar and acidity, was also observed. Concerning the wine aromatic potential, no differences clearly appeared.

Projected changes in vine phenology of two varieties with different thermal requirements cultivated in La Mancha DO (Spain) under climate change scenarios

The aim of this work was to analyze the phenology variability of Tempranillo and Chardonnay cultivars, related to the climatic characteristics in La Mancha Designation of Origin, and their potential changes under climate change scenarios. Phenological dates referred to budbreak, flowering, veraison and harvest were analyzed for the period 2000-2019. The weather conditions at daily time scale, recorded during the same period, were also evaluated. The thermal requirements to reach each of these phenological stages were calculated and expressed as the GDD accumulated from DOY=60. Changes in phenology were projected by 2050 and 2070 taking into account those values and the projected temperatures and precipitation, simulated under two Representative Concentration Pathway (RCP) scenarios –RCP4.5 and RCP8.5– using an ensemble of models. The average phenological dates during the period under study were, April 16th ± 6.6 days and April 5th ± 6.0 days for budbreak, May 31st ± 6.0 days and May 27th ± 5.3 days for flowering, July 26th ± 5.6 days and July 25th ± 5.8 days for veraison, and Ago 23rd ± 10.8 days and Ago 17th ± 9.0 days for harvest, respectively, for Tempranillo and Chardonnay. The projected changes in temperature imply an average change in the maximum growing season (April-August) temperatures of 1.2 and 1.9°C by 2050, and 1.6 and 2.6°C by 2070, under the RCP4.5 and RCP8.5 scenarios, respectively. A reduction in precipitation is predicted, which vary between 15% for 2050 under RCP4.5 scenario and up to 30% by 2070 under RCP8.5. The advance of the phenological dates for 2050, could be of 6, 7, 7, and 8 days for Tempranillo and 4, 6, 6 and 9 days for Chardonnay, respectively for budbreak, flowering, veraison and harvest under the RCP4.5 scenario. Under the RCP8.5 emission scenario, the advance could be up to 30% higher.