BIOPROTECTION, HOW AND WHY?
- BIOProtection consists in the addition of a living organism to occupy the ecological niche and thus limit the predominance of potentially undesirable indigenous microorganisms.
- In practical winemaking terms, it means applying selected microorganisms to the grapes or must to limit the occurrence of changes harmful to wine quality.
- Microorganisms selected from the grape and/or must microflora, to guarantee their oenological origin.
- Microorganisms with low fermentation activity at the inoculated dose and able to colonise the medium.
- Selection of high-quality strains from among recognised species.
TWO BIOPROTECTION SOLUTIONS FROM LAFFORT®
PRE-FERMENTATION PHASES AT VERY LOW TEMPERATURE
The LAFFORT® solution for the BIOProtection of grapes and musts at low temperatures.
Specific strain of the species Metschnikowia pulcherrima for especially long pre-fermentation phases.
- During stabulation of white and rosé musts.
- In the tank, for long periods of cold soaking before fermentation.
In the case of long pre-fermentation phases at very low temperature, the presence of nutrient-rich solids can encourage the growth of indigenous microflora.
The latter can lead to spontaneous alcoholic fermentation, making must clarification more difficult and impacting the final quality of the wine. This also makes it more difficult to establish a selected S. cerevisiae yeast to carry out a clean alcoholic fermentation.
Monitoring reducing sugar and assimilable nitrogen during stabulation makes it possible to verify the absence of fermentation activity during the 4-week stabulation.
Impact of ZYMAFLORE® KHIOMP on indigenous S. cerevisiae yeasts.
Distribution of the different yeast populations in the must at the end of stabulation (counting on specific medium).
Control tank: more than 90% of the microflora present at the end of stabulation are indigenous S. cerevisae yeasts.
With inoculation: significant colonisation of ZYMAFLORE® KHIOMP, limiting the development of indigenous S. cerevisiae yeasts (only 36% of total yeasts). BIOProtection limits the risk of fermentation starting spontaneously during stabulation.
BIOPROTECTION & SO2 REDUCTION
The LAFFORT® solution for the BIOProtection of grapes and musts, particularly suitable as part of an SO2 reduction strategy.
Made up of 2 strains of the species Torulaspora delbrueckii and Metschnikowia pulcherrima in order to adapt to all situations and preserve wine quality.
- Early application to all equipment in contact with the grapes: harvesting and grape reception equipment, transport tankers, etc.
- When red grapes go into tank, regardless of the pre-fermentation protocol.
- At the latest, after pressing for BIOProtection of musts until inoculation with S. cerevisiae (AF).
Impact of SO2 reduction.
When SO2 is reduced, the microbiological pressure on the must is increased. Indigenous populations are larger than after conventional sulphite addition. Depending on the oenological context, the effect can be variable (table 2).
Influence of sulphite levels according to the species at the pre-fermentation stage.
Reducing SO2 is not just quantitative. It is also qualitative and reshapes the microbial balance of the must.
Not all yeast species present react in the same way to variations in SO2 levels. Among them, one seems particularly favoured in situations where use of SO2 is limited: Hanseniaspora uvarum (production of VA).
EFFECT OF BIOPROTECTION IN THE CONTEXT OF SO2 REDUCTION
Comparison of Merlot grapes from the same harvest vinified without SO2 and both with and without BIOProtection . In the case of the grapes without sulphite and without BIOProtection, the microbiological pressure of the must is such that it prevents the inoculated S. cerevisiae yeast from becoming established after the pre-fermentation period. The consequences are oxidative markers at higher levels than in the case of the no-sulphite but BIOProtected grapes, for which the alcoholic fermentation has been better controlled.
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