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…

Descriptive analysis of Sangiovese and Cabernet-Sauvignon wines from different terroirs in D.O.C. Bolgheri (Tuscany)

Different terroirs have been identified in Bolgheri area (a viticultural appellation in the Tirrenian coast of Tuscany) by the aid of pedological, landscape and agronomic observations in 1993. Numerous preliminary observations suggested that wines obtained from these different terroirs were unique.

Exploring the mechanisms of grapevine single berry development and ripening

The strategy of single berry phenotyping is a recently rediscovered research tool that has gained great attention. The latest studies have indicated that previous physiological models based on pooling asynchronous populations of berries provided biased or blurred information on berry development key players. The possibility of monitoring and sampling single synchronized berries to study their development sequentially has opened new lines of research aimed at unraveling the genes that regulate grapevine fruit development. This study aimed to decipher the gene pathways responsible for the activation/deactivation of physiological processes involved in the green phase of growth, the onset of ripening, and the second growth phase.

Grape ripening timing as a base for viticultural zoning: an agro-ecological approach

Due to the central role of the ripening timing in the evaluation of the varietal response to the environmental resources, a method to manage maturation curves has been developed. The method produces an index of veraison precocity and overcomes several methodological problems, like the visual evaluation of the veraison point and the multi-annual and multi-varieties data processing. It is based on a statistical and mathematical processing of the sugar ripening curves.

Influence of must fining on wine pinking: relationship between electrochemical and colorimetric measurements and pinking attitude of wine

“Pinking” is a term used to define an abnormal pink coloration assumed by white wines in certain cases. Despite the are many hypotheses about the causes of this phenomenon, pinking still represents an issue for the wine industry. In the absence of reliable preventive strategies, wineries often rely on treatments such as charcoal fining, which is also negatively impacting wine aroma. This study aims at evaluating the potential of different fining agents based on animal or vegetal proteins to prevent wine pinking when applied at the level of must clarification. The work was carried out on Lugana wines, which is well-recognised as sensible to pinking problems. METHODS: Two experimental Lugana musts were obtained by applying a standard winemaking protocol and were then clarified with different commercial preparations based on vegetal proteins or casein, alone or in combination with PVPP. A control only using pectolytic enzyme was also prepared. Finings were carried out at 4°C for 16h, and the clear must (200 NTU) was then fermented in controlled conditions.

A study on the oenological potentiality of the territory of a cooperative winery in Valpolicella (Italy)

A 3-year zoning study promoted by the Cooperative Winery Valpolicella (Negrar, Verona, Italy) was carried out on a wine territory of about 500 ha.