Protecting white and rosé musts from oxidation and spoilage

Early must protection: a critical challenge for winemakers

From harvest to pressing, grape must is highly vulnerable.

Oxygen exposure, microbial contamination and mechanical harvesting can rapidly trigger oxidation and spoilage, especially in white and rosé winemaking. Many wineries are looking to reduce sulphite additions while maintaining freshness and microbial stability.

Bioprotection offers an natural approach using selected microorganisms to stabilise must from the earliest stages of the process.

LEVEL² INITIA™ is a non-Saccharomyces yeast (Metschnikowia pulcherrima) developed specifically to protect grape musts against both oxidation and microbial spoilage.

A natural solution for Low-SO₂ winemaking

LEVEL² INITIA™ was isolated in Burgundy in collaboration with the Institut Français de la Vigne et du Vin (IFV). This non-fermentative yeast was selected for its ability to protect musts while helping reduce sulphite additions.

Unlike fermentative yeasts, LEVEL² INITIA™ does not initiate alcoholic fermentation. Instead, it acts as a protective biological barrier during the early stages of vinification.

Key characteristics include:

This makes it particularly suitable for protecting white and rosé musts from the vineyard to the cellar.

Double protection: oxidation control and microbial stability

LEVEL² INITIA™ protects must quality through 2 complementary mechanisms.

Oxygen scavenging to prevent browning

The strain was selected for its strong ability to consume oxygen rapidly in grape must.

Scientific trials have shown that the addition of Metschnikowia pulcherrima strain MP1 significantly increases oxygen consumption in must compared to untreated controls. This rapid oxygen uptake helps limit oxidation reactions responsible for browning and aroma degradation. The strain also contributes to reducing copper levels, a heavy metal known to accelerate oxidative reactions in must.

Together, these mechanisms help preserve aromatic freshness from the earliest processing steps.

Active control of spoilage microorganisms

Beyond oxidation protection, LEVEL² INITIA™ also limits the growth of spoilage microorganisms.

This yeast produces pulcherriminic acid, a compound that binds iron in the must and makes it unavailable to other microbes. Because iron is essential for microbial growth, this mechanism reduces the development of contaminants such as:

Data from Sauvignon Blanc trials show significantly lower populations of these microorganisms when LEVEL² INITIA™ is used compared to untreated controls.

Microbial population in a Sauvignon Blanc (Spain) after 96 hours at 14 °C

Why strain selection matters

Not all Metschnikowia pulcherrima strains provide the same level of bioprotection.

Recent research screening 46 strains across six Metschnikowia species revealed strong variability in antimicrobial performance. LEVEL² INITIA™ demonstrated significantly stronger protection against key contaminants such as acetic acid bacteria compared with other strains.

This highlights the importance of selecting well-characterised strains for reliable bioprotection.

Supporting fresh and stable wines from the start

For winemakers seeking to maintain wine freshness while reducing chemical inputs, early-stage bioprotection provides a practical and reliable solution. By rapidly colonising musts and controlling microbial competition, LEVEL² INITIA™ helps create a stable environment for fermentation.

Its benefits include:

Rethinking must protection

In modern white and rosé winemaking, protecting must quality starts well before fermentation.

LEVEL² INITIA™ combines oxygen scavenging, microbial competition and early colonisation to stabilise musts from harvest through to fermentation. For wineries facing increasing oxidation pressure and evolving consumer expectations around sulphites, this approach represents a powerful new tool for protecting wine quality from the very beginning.