Enoforum 2021
IVES 9 IVES Conference Series 9 Enoforum Web 9 Enoforum Web Conference 2021 9 Cellar session 9 All acids are equal, but some acids are more equal than others: (bio)acidification of wines

All acids are equal, but some acids are more equal than others: (bio)acidification of wines

Abstract

Insufficient acidity in grapes from warm(ing) climates is commonly corrected through addition of tartaric acid during vinification, and less so with other organic acids. One alternative approach involves bio-acidification with certain strains of Lachancea thermotolerans (LT) via lactic acid production during fermentation. Our previous work delivered a superior LT starter capable of lowering wine pH by ~0.5 units when used in co-cultures with Saccharomyces cerevisiae (SC).  Here, we aimed to i) compare the profiles of the bio-acidified LT wines and the acid-adjusted SC wines, and ii) evaluate the use of LT wines as blending components. For this purpose, high sugar/pH Merlot grapes (14.5 ° Bé; pH 3.9) were fermented with a sequential culture of LT and SC, and an SC monoculture control. The two obtained wines blended in three proportions (1:3, 1:1, 3:1), and the aliquots of the SC control (pH 4) were also acidified with either tartaric or lactic acid to the pH of the LT wine (pH 3.5).  Chemical analysis revealed major differences in a range of compositional parameters, which were reflected in the sensory profiles of wines, as confirmed via ‘Rate-All-That-Apply’ evaluation by wine experts (n=30). Sensory profiles of the bio-acidified LT wine and the lactic acid-adjusted SC wine were similar, and contrasting to the tartaric acid-adjusted SC wine. Despite the identical initial matrix, adjustment with lactic acid resulted in intenser ‘red fruit’ flavour, and lower ‘hotness’, ‘bitterness’ and ‘body’ relative to the adjustment with tartaric acid, driven by increases in ‘sourness’. The profiles of blends were modulated depending on the proportion of the bio-acidified wine, thus highlighting the potential of this approach to fine-tune ‘freshness’ and differentiate wine styles.

DOI:

Publication date: April 23, 2021

Issue: Enoforum 2021

Type: Article

Authors

Ana Hranilovic 1, 2; Marina Bely 1; Isabelle Masneuf-Pomarede 1,3; Warren Albertin 1,4, Vladimir Jiranek 2, 5

1 ISVV, University of Bordeaux, Villenave d’Ornon, France
Department of Wine and Food Science, The University of Adelaide, Adelaide, Australia
Bordeaux Sciences Agro, Gradignan, France
ENSCBP, Bordeaux INP, Pessac, France
The Australian Research Council Training Centre for Innovative Wine Production, Adelaide, Australia

Contact the author

Tags

Enoforum 2021 | IVES Conference Series

Citation

Related articles…

Advances in phenology modelling of the grapevine

Historical records of grapevine phenology have been collected over decades throughout different winegrowing regions. These records have demonstrated advances in key developmental stages such as budburst, flowering and veraison because of increased temperatures due to climate change.

ANTIOXIDANT CAPACITY OF INACTIVATED NON-SACCHAROMYCES YEASTS

The importance of the non-Saccharomyces yeasts (NSY) in winemaking has been extensively reviewed in the past for their aromatic or bioprotective capacity while, recently their antioxidant/antiradical potential has emerged under winemaking conditions. In the literature the antioxidant potential of NSY was solely explored through their capacity to improve glutathione (GSH) content during alcoholic fermen- tation [1], while more and more studies pointed out the activity of the non-glutathione soluble fraction released by yeasts [2].

Assyrtiko wines of Santorini produced by different autochthonous yeasts: Differences in aromatic and organoleptic profiles

Different yeasts were isolated from spontaneous fermentation of Assyrtiko grape must in Santorini Island, Greece. Molecular typing revealed the presence of three Saccharomyces cerevisiae strains (S9, S13, S24) and one strain of the yeast species Nakazawaea ishiwadae (N.i). The four isolated strains were further tested in laboratory scale fermentations of Assyrtiko must in pure inoculation cultures and in sequential inoculation (72 hours) of each S. cerevisiae strain with the strain of N. ishiwadae. All fermentation trials were realised in duplicate.

Implementation of hyperspectral image analysis for evaluating table grape quality on bunch and berry level

Typically, subjective, and visual methods are used by grape growers to assess harvest maturity. These methods may not accurately represent the maturity of an entire vineyard – especially if extensive and representative sampling was not used. New technologies have been investigated for improved harvest management decisions. Spectroscopy methods utilizing the near-infrared region of the light spectrum is one such technology investigated as an alternative to classic methods and particularly the application of hyperspectral imaging (HSI) has recently gained attention in research. HIS is a spectroscopic technique that obtains hundreds of images at different wavelengths collecting spectral data for each pixel in the sample i.e., providing both spectral and spatial data.

Social and environmental impacts of the adoption of a variety of table grape in the region of vale do São Francisco – Brazil

This study explores and analyzes the socio-environmental implications associated with the cultivation of the “brs-vitoria” table grape variety. Focusing on its adoption by farmers in the vale do submédio São Francisco region in Brazil, this study delves into the diverse impacts and changes brought about since its introduction, encompassing both the social and environmental dimensions of agricultural practices in the area. Embrapa, brazil’s federal agricultural research institution, encompasses a network of 43 thematic research centers spread across the nation.