Macrowine 2021
IVES 9 IVES Conference Series 9 New biological tools to control and secure malolactic fermentation in high pH wines

New biological tools to control and secure malolactic fermentation in high pH wines

Abstract

Originally, the role of the malolactic fermentation (MLF) was simply to improve the microbial stability of wine via biological deacidification. However, there is an accumulation of evidence to support the fact that lactic acid bacteria (LAB) also contribute positively to the taste and aroma of wine. Many different LAB enter into grape juice and wine from the surface of grape berries, cluster stems, vine leaves, soil and winery equipment. Due to the highly selective environment of juices and wine, only a few types of LAB are able to grow. Wine pH is most selective, and at pH below 3.5 generally only strains of Oenococcus oeni can survive and express malolactic activity, while wines with pH above 3.5 can contain various species of Pediococcus, as well as strains of Lactobacillus. The trend toward harvesting higher maturity grapes has resulted in the processing of higher pH musts and the production of wines containing increased levels of alcohol. These conditions favor the growth of indigenous bacteria and often O. oeni does not prevail at the end of alcoholic fermentation. More Lactobacillus sp. predominate and are often responsible for spontaneous MLF (du Toit et al. 2011). Some L. plantarum strains can tolerate the high alcohol concentrations and SO2 levels normally encountered in wine. Due to their very complex and diverse metabolism a range of compositional changes can be induced, which may affect the quality of the final product positively or negatively. A recent isolate have shown most interesting results, not only for its capacity to induce MLF after direct inoculation in freeze-dried form, but also for their positive contribution to the wine aroma. Co-inoculation (inoculation of selected wine LAB 24 hours after the yeast) can ensure the early implantation and dominance of the selected strain, the early onset and completion of MLF, and can possibly prevent the appearance of the spoilage yeast and bacteria. Applying an important L. plantarum inoculum with high malolactic activity assures an immediate dominance, as well as predictable and complete MLF in short time and allows an early stabilization of the wine. Since it degrades hexose sugars by the homo-fermentative pathway, which poses no risk of acetic acid production from the residual sugars that may be present in high pH wines, it is an interesting alternative to control MLF in high pH wines.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Sibylle Dr. Krieger-Weber*, Anthony Silvano, Magali Deleris-Bou

*Lallemand SAS

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

The effect of cropload on the volatile aroma characteristics of ‘Beihong’ and ‘Beimei’ red wine

Beihong and Beimei were bred as winemaking cultivars released by Institute of Botany, the Chinese Academy of Sciences in 2008. The cultivars are selected from the population of ‘Muscat Hamburg’ (Vitis vinifera) ×V. amurensis. They are extended to most provinces in North of China because they have strong resistance to cold and disease and need not be buried in soil in winter. To better understand the effect of cropload on volatile compounds during wine-making, we surveyed volatiles composition and content of different cropload level in 3-years-old ‘Beihong’ and ‘Beimei’ vines which planted in east foot of Helan mountain of Ningxia (EHN).

Application of high power ultrasounds during red wine vinification

Wine color is one of the main organoleptic characteristics influencing its quality. It is of especial interest in red vinifications due to the economic resources that wineries have to invest for the extraction of the phenolic compounds responsible of wine color, compounds that are mainly located inside the skin cell vacuoles. Moreover, these phenolic compounds not only influence color but also other organoleptic properties such as body, mouthfeel, astringency and flavour. The transference of phenolic compounds from grapes to must during vinification is closely related with the type of grapes and the winemaking technique.

How do different oak treatment affect the sensory composition of Chenin blanc wines over time?

Wooden barrels have been the preferred method for oak maturation for wines, but the use of alternative oak products, such as staves and oak chips have increased in South Africa due to lower production costs. This study investigated the effect of different oak products used during fermentation and ageing on the sensory profile, degree of liking and perceived quality of a South African Chenin blanc wine. The different wine treatments included an unoaked tank control wine, wines matured in 5th fill barrels, wines matured in new barrels from three different cooperages, and wines matured in 5th fill barrels with stave inserts from two different cooperages.

DNA and type of grain: which factor does better explain sensory differences of sessile and pedunculate oaks?

Sessile oak and pedunculate oak have shown several differences of interest for enological purposes. Tannic and aromatic composition among sessile oak or pedonculate oak has been well studied. Sessile oak is generally more aromatic than pedunculated, while the later is more tannic. This scientific point of view is rarely applied to classify oak in cooperages. Most coopers use the type of grain to distinguish wide and thin grain.

Fining-Derived Allergens in Wine: from Detection to Quantification

Since 2012, EU Commission approved compulsory labeling of wines treated with allergenic additives or processing aids “if their presence can be detected in the final product” (EU Commission Implementing Regulation No. 579/2012 of 29 June 2012). The list of potential allergens to be indicated on wine labels comprises sulphur dioxide and milk- and egg- derived fining agents, including hen egg lysozyme, which is usually added in wines as preservative. In some non-EU countries, the list includes gluten, tree nuts and fish gelatins. With the exception of lysozyme, all these fining proteins were long thought to be totally removed by subsequent winemaking processings (e.g. bentonite addition).