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…

The start of Croatian grapevine breeding program

Modern viticulture in Croatia and the world is mainly based on the grapevine varieties susceptible to various diseases and pests, which leads to unsustainable use of large amounts of pesticides. The sustainable development of viticulture in the future will only be possible by increasing the resistance of the grapevine through the development of new resistant varieties. Breeding programs have been launched in the leading wine-growing countries with the aim of developing resistant varieties possessing high quality level. Coratia is rich in in native grapevine varieties that are the basis of wine production, and are not included in the breeding programs of other countries.

Effect of vineyard nitrogen management on Souviginer gris wine sensory quality and aromatic compounds

Fungus-Resistant Grape (FRG) varieties represent a promising approach to address the challenges of climate change and sustainability in viticulture.

Terroir analysis and its complexity

Terroir is not only a geographical site, but it is a more complex concept able to express the “collective knowledge of the interactions” between the environment and the vines mediated through human action and “providing distinctive characteristics” to the final product (OIV 2010). It is often treated and accepted as a “black box”, in which the relationships between wine and its origin have not been clearly explained. Nevertheless, it is well known that terroir expression is strongly dependent on the physical environment, and in particular on the interaction between soil-plant and atmosphere system, which influences the grapevine responses, grapes composition and wine quality. The Terroir studying and mapping are based on viticultural zoning procedures, obtained with different levels of know-how, at different spatial and temporal scales, empiricism and complexity in the description of involved bio-physical processes, and integrating or not the multidisciplinary nature of the terroir. The scientific understanding of the mechanisms ruling both the vineyard variability and the quality of grapes is one of the most important scientific focuses of terroir research. In fact, this know-how is crucial for supporting the analysis of climate change impacts on terroir resilience, identifying new promised lands for viticulture, and driving vineyard management toward a target oenological goal. In this contribution, an overview of the last findings in terroir studies and approaches will be shown with special attention to the terroir resilience analysis to climate change, facing the use and abuse of terroir concept and new technology able to support it and identifying the terroir zones.

Influence of organic plant treatment on the terroir of microorganisms

Several factors like vineyard site, climate, grape variety, ripeness, physical health of the grapes and pest management influence the populations of indigenous yeasts on grapes and later on in spontaneous fermentations.

Riesling aroma composition in light of changing global temperatures – delving into the effects of warmer nights on the volatile profile of riesling grapes

Climate is a key parameter when the modulation of berry and subsequent wine composition is considered. Recent decades have already seen an increase in global surface temperatures