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…

Protected Designation of Origin (D.P.O.) Valdepeñas: classification and map of soils

The objective of the work described here is the elaboration of a map of the different types of vineyard soils that to guide the famers in the choice of the most productive vine rootstocks and varieties. 90 vineyard soils profiles were analysed in the entire territory of the Origen Denominations of Valdepeñas. The sampling was carried out in 2018 (June to October) by making a sampling grid, followed by photointerpretation and control in the field. The studied soils can be grouped into 9 different soil types (according to FAO 2006 classification): Leptosols, Regosols, Fluvisols, Gleysols, Cambisols, Calcisols, Luvisols and Anthrosols. A map showing the soil distribution with different type of soils has been made with the ArcGIS program. Regarding to the choice of rootstock, Calcisoles are soils with a high active limestone content, so the rootstocks used in these soils must be resistant to this parameter; Luvisols are deep soils with high clay content, so they will support vigorous rootstocks. Because the cartographic units are composed of two or more subgroups, with are associated in variable proportions, 9 different soil associations have been established; Unit 1: Leptosols, Cambisols and Luvisols (80%, 15% and 5% respectively); Unit 2: Cambisols with Regosols and Luvisols (40%, 30% and 30% respectively); Unit 3: Cambisols and Gleysols with Regosols (40%, 40% and 20% respectively); Unit 4: Regosols with Cambisols, Leptosols and Calcisols (40%, 30%, 15% and 15% respectively); Unit 5: Cambisols, Leptosols, Calcisols and Regosols (25% each of them); Unit 6: Luvisols with Cambisol and Calcisols (80%, 10% and 10% respectively); Unit 7: Luvisols and Calcisols with Cambisols (40%, 40% and 20% respectively); Unit 8: Calcisols with, Cambisols and Luvisols (80%, 10% and 10% respectively); Unit 9: Anthrosols. These study allow to elaborate the first map of vineyard soils of this Protected Designation of Origin in Castilla-La Mancha.

Leaf vine content in nutrients and trace elements in La Mancha (Spain) soils: influence of the rootstock

The use of rootstock of American origin has been the classic method of fighting against Phylloxera for more than 100 years. For this reason, it is interesting to establish if different rootstock modifies nutrient composition as well as trace elements content that could be important for determining the traceability of the vine products. A survey of four classic rootstocks (110-Richter, SO4, FERCAL and 1103-Paulsen) and four new ones (M1, M2, M3 and M4) provided by Agromillora Iberia. S.L.U., all of them grafted with the Tempranillo variety, has been carried out during 2019. The eight rootstocks were planted in pots of 500 cc, on three soils with very different characteristics from Castilla-La Mancha (Spain). In the month of July, the leaves were collected and dried in a forced air oven for seven days at 40ºC. Then, the samples were prepared for the analysis determination, carried out by X-Ray fluorescence spectrometry. The results obtained showed that in the case of content in mineral elements in leaf, separated by soil type, we can report the importance of few elements such as Si, Fe, Pb and, especially, Sr. The rootstock does not influence the composition of the vine leaf for the studied elements that are the most important in determining the geochemical footprint of the soil. The influence of the soil can be discriminated according to some elements such as Fe, Pb, Si and, especially, Sr.

Delaying irrigation initiation linearly reduces yield with little impact on maturity in Pinot noir

When to initiate irrigation is a critical annual management decision that has cascading effects on grapevine productivity and wine quality in the context of climate change. A multi-site trial was begun in 2021 to optimize irrigation initiation timing using midday stem water potential (ψstem) thresholds characterized as departures from non-stressed baseline ψstemvalues (Δψstem). Plant material, vine and row spacing, and trellising systems were concomitant among sites, while vine age, soil type, and pruning systems varied. Five target Δψstem thresholds were arranged in an RCBD and replicated eight times at each site: 0.2, 0.4, 0.6, 0.8, and 1.0 MPa (T1, T2, T3, T4, and T5, respectively). When thresholds were reached, plots were irrigated weekly at 70% ETc. Yield components and berry composition were quantified at harvest. To better generalize inferences across sites, data were analyzed by ANOVA using a mixed model including site as a random factor. Across sites, irrigation was initiated at Δψstem = 0.24, 0.50, 0.65, 0.93, and 0.98 MPa for T1, T2, T3, T4, and T5, respectively. Consistent significant negative linear trends were found for several key yield and berry composition variables. Yield decreased by 12.9, 15.9, 19.5, and 27.4% for T2, T3, T4, and T5, respectively, compared to T1 (p < 0.0001) across sites that were driven by similarly linear reductions in berry weight (p < 0.0001). Comparatively, berry composition varied little among treatments. Juice total soluble solids decreased linearly from T1 to T5 – though only ranged 0.9 Brix (p = 0.012). Because producers are paid by the ton, and contracts simply stipulate a target maturity level, first-year results suggest that there is no economic incentive to induce moderate water deficits before irrigation initiation, regardless of vineyard site. Subsequent years will further elucidate the carryover effects of delaying irrigation initiation on productivity over the long term.

Elevational range shifts of mountain vineyards: Recent dynamics in response to a warming climate

Increasing temperatures worldwide are expected to cause a change in spatial distribution of plant species along elevational gradients and there are already observable shifts to higher elevations as a consequence of climate change for many species. Not only naturally growing plants, but also agricultural cultivations are subject to the effects of climate change, as the type of cultivation and the economic viability depends largely on the prevailing climatic conditions. A shift to higher elevations therefore represents a viable adaptation strategy to climate change, as higher elevations are characterized by lower temperatures. This is especially important in the case of viticulture because a certain wine-style can only be achieved under very specific climatic conditions. Although there are several studies investigating climatic suitability within winegrowing regions or longitudinal shifts of winegrowing areas, little is known about how fast vineyards move to higher elevations, which may represent a viable strategy for winegrowers to maintain growing conditions and thus wine-style, despite the effects of climate change. We therefore investigated the change in the spatial distribution of vineyards along an elevational gradient over the past 20 years in the mountainous wine-growing region of Alto Adige (Italy). A dataset containing information about location and planting year of more than 26000 vineyard parcels and 30 varieties was used to perform this analysis. Preliminary results suggest that there has been a shift to higher elevations for vineyards in general (from formerly 700m to currently 850 m a.s.l., with extreme sites reaching 1200 m a.s.l.), but also that this development has not been uniform across different varieties and products (i.e. vitis vinifera vs hybrid varieties and still vssparkling wines). This is important for climate change adaptation as well as for rural development. Mountain areas, especially at mid to high elevations, are often characterized by severe land abandonment which can be avoided to some degree if economically viable and sustainable land management strategies are available.

Phenolic composition of Tempranillo Blanco grapes changes after foliar application of urea

Our research aimed to determine the effect and efficiency of foliar application of urea on the phenolic composition of Tempranillo Blanco grapes. The field experiment was carried out in 2019 and 2020 seasons and the plot was located in D.O.Ca Rioja (North of Spain). The vineyard was Vitis vinifera L. Tempranillo Blanco and grafted on Richter-110 rootstock. The treatments were control (C), whose plants were sprayed with water and three doses of urea: plants were sprayed with urea 3 kg N/ha (U3), 6 kg N/ha (U6) and 9 kg N/ha (U9). The applications were performed in two phenological stages, pre-veraison (Pre) and veraison (Ver). Also, each of the treatments was repeated one week later. Control and treatments were performed in triplicate and arranged in a randomised block design. Grapes were harvested at optimum ripening stage. High-performance liquid chromatography was used to analyse the phenolic composition of the grapes. Finally, the results obtained from the analytical determinations – flavonols, flavanols and non-flavonoid (hydroxybenzoic acids, hydroxycinnamic acids and stilbenes) – were studied statistically by analysis of variance. The results showed that, in 2019, U6-Pre and U9-Pre treatments increased the hydroxybenzoic acid content in grapes, and also all foliar treatments applied at Pre enhanced the stilbene concentration. Moreover, U3-Ver was the only treatment that rose flavonol and stilbene contents in the Tempranillo Blanco grapes. In 2020, all treatments applied at Pre enhanced the flavonol concentration in grapes. Furthermore, U3-Pre and U9-Pre treatments increased stilbene content in grapes. Nevertheless, the hydroxybenzoic acid content was improved by U6-Ver and U9-Ver and besides, hydroxycinnamic acid concentration in grapes was increased by all treatments applied at Ver. In conclusion, the lower and highest dose of urea (U3 and U9), applied at pre-veraison, were the best treatments to improve the Tempranillo Blanco grape phenolic composition.