Tannin profile of different Monastrell wines and its relation to projected market prices

Highlights

• Wines elaborated based on different projected market prices differed in tannin composition.

• Those wines elaborated as premium wines presented the highest phenolic and tannin content.

• Grape skin tannins were largely present in those wines projected as premium wines.

Abstract

This study focuses on the differences or similarities in tannin composition and concentration in Monastrell wines from different wineries from the same geographic area and, within each winery, from wines elaborated based on different projected market prices, to determine whether there is any relationship between the wine tannin composition and the projected price. The tannin composition of the different wines, all of them analyzed at the same point during winemaking, indicated that those elaborated as premium wines presented higher phenol and tannin contents. The mean degree of polymerization of these wines was also positively related with the projected price, which agreed with the results obtained by size exclusion chromatography, that showed that wines with high projected prices had a higher proportion of polymeric tannins, suggesting that techniques favoring the extraction of skin tannins were mostly used in those wines projected as premium wines, probably looking for greater mouthfeel complexity.

Introduction

Wines are a complex matrix, appreciated for their stylistic variation and complexity. Their composition depend on grape variety and production area but also on the winemaking techniques used.

In commercial wineries, the vinification process for wines intended for different market prices varies, from using different quality grapes to different enological processes, such as the number of pump-overs, the use of prefermentative additives such as the maceration enzymes, the duration of the skin maceration process and also differences in the aging systems such as the use of wood in the form of barrels, staves or chips (Cadot et al., 2012, Cáceres et al., 2012). The objective is to obtain wines sufficiently different as regards quality parameters to justify their allocation to different categories.

The different enological practices prior to aging will cause the differential extraction of compounds from grapes, which will influence the concentration and composition of phenolic compounds in the wines (Sacchi, Bisson, & Adams, 2005). Among phenolic compounds, tannins are responsible for wine mouthfeel, body and astringency, while they also have a role in stabilizing wine color. Studies have shown that overall intensity and persistence are positively correlated with astringency, and therefore to tannin content. A relationship between tannin content and allocation grade has also been described (Mercurio, Dambergs, Cozzolino, Herderich, & Smith, 2010).

Monastrell (Mourvedre in France, Mataro in Australia and California) is a black-skinned variety that has been grown in vineyards all around the western Mediterranean countries for centuries. It is now grown extensively throughout Spain and southern France, as well as in California and South Australia. It is well adapted to warm, dry climates and has small, thick-skinned berries which are high in phenolics and have the potential to produce deeply colored tannic wines.

Under Spanish wine law, Monastrell is one of the primary red wine grape varieties in the Denomination of Origin of Jumilla, Bullas, Yecla, Valencia, Almansa and Alicante (all located in the southeastern Spain), where there is a high production of monovarietal Monastrell wines. Most wineries in these areas market several Monastrell monovarietal wines with different prices, to cover a wide range of consumers. Since all these wineries share quite the same geographic area, with similar soil and climate conditions (although we cannot rule out the existence of some areas presenting quite particular agroclimatic conditions) and the main variety, differences among wines from different wineries and among wines with different projected prices within each winery mainly arise from the agronomical grape management and different enological techniques used during winemaking, as also stated by Cáceres et al. (2012).

This study will focused on the analysis of the differences and similarities of the concentration and composition of tannins in Monastrell monovarietal wines elaborated in different wineries from the same geographical area to determine whether their concentration and characteristics change according to the wine projected price.