How to stop Brettanomyces before it starts: early bioprotection with LEVEL² SALVA™

Brettanomyces often starts earlier than winemakers think

When winemakers think about Brettanomyces, they often think about barrel ageing, post-malolactic fermentation, or wines already showing volatile phenol defects. But in reality, Brett contamination can begin much earlier, sometimes even before the grapes reach the tank.

Brettanomyces bruxellensis is a well-known spoilage microorganism in wine because of its ability to produce unpleasant sensory characters such as barnyard, band-aid and clove-like notes. It can be present at different stages of the winemaking process, and it may also already exist in the vineyard, sometimes concentrated in specific blocks.

That changes the prevention strategy entirely.

If Brett is already present on grapes at harvest, waiting until after fermentation to react is often too late. By then, the contamination may already be established, and the wine may already be exposed to the formation of volatile phenols. This is why early-stage control, at harvest, during transport, or at tank filling, becomes a highly strategic intervention point.

Why does early Brett control matter?

Not all vineyard contamination is random.

Brettanomyces can be associated with specific vineyard blocks, which means some wineries may face recurring contamination year after year from the same fruit source.

That’s important, because recurring block contamination is not just a cellar hygiene issue — it becomes a vineyard-to-tank risk management issue.

If a winery knows that fruit from a particular block is repeatedly associated with Brett, the most effective strategy is no longer simply “watch closely later.” It becomes “intervene immediately.”

That is exactly the positioning of LEVEL² SALVA™: a selected bioprotection yeast developed to control Brettanomyces at the earliest stages of production, before it can establish itself in must or wine.

What is LEVEL² SALVA™ and how does it work?

LEVEL² SALVA™ is a selected wine yeast from the species Suhomyces pyralidae, originally selected by the South African Grape and Wine Research Institute (Stellenbosch University) in Cabernet Sauvignon must. Unlike general bioprotection strategies designed for broad microbial competition, LEVEL² SALVA™ was specifically selected for its targeted activity against Brettanomyces.

Its mode of action is linked to the production of the “Brett inhibition factor.” This compound disrupts the cell walls of Brettanomyces cells, leading to a strong inhibitory effect on their development. The microscopy images illustrate this clearly: compared with untreated cells, Brettanomyces bruxellensis cells exposed for 24 hours to the Brett inhibition factor show visible structural damage.

This is what makes LEVEL² SALVA™ different in practical terms: it is not simply competing with Brett for nutrients or ecological space. It is delivering a more targeted, control effect.

Stopping Brett at the cellar door: why are harvest and tank filling critical moments?

One of the strongest ideas in this Under Investigation is that Brett prevention should not begin only after fermentation. It should begin as fruit enters the winery.

If Brettanomyces is present on grapes, then harvest, transport and tank filling become the most logical moments to reduce the population before it can proliferate.

This is especially relevant because tank filling is described as an opportune time for Brettanomyces to proliferate. Must is freshly available, the microbial environment is dynamic, and contamination can spread rapidly if not controlled.

Trial results: spraying grapes at harvest reduced Brett after MLF

A winery trial on hand-harvested Tempranillo grapes in Spain tested this exact concept. LEVEL² SALVA™ was applied by spraying directly onto the grapes at harvest, and the wine was compared with an untreated control through the same winemaking process.

At the end of malolactic fermentation, the Brett population in the treated wine was 2.4 times lower than in the control.

That is important because the treatment was applied not in the finished wine, but on the grapes, before the entire fermentation sequence even began.

This trial supports a very practical message for winemakers: if contamination risk is known or suspected, controlling Brett on fruit before fermentation can reduce the Brett load still detectable after MLF.

Trial results: strong control in a recurrent Syrah block contamination

In a winery in Columbia Gorge AVA, Washington, USA, repeated Brett issues had been traced back to grapes coming from a specific Syrah block in the vineyard. During tank filling, both tanks received 4 g/hL SO₂, but only one tank also received LEVEL² SALVA™, while the second tank served as the control. After identical alcoholic and malolactic fermentations, the results were measured at the end of MLF.

The control tank showed almost 4 × 10³ Brettanomyces cells/mL, while the tank inoculated early with LEVEL² SALVA™ showed a very low Brett population in comparison.

Can LEVEL² SALVA™ control volatile phenols at tank filling?

Tank filling is not only a moment where Brett populations can increase, but also a stage where volatile phenol production can begin. And importantly, even when volatile phenols remain below their formal sensory threshold, they may still negatively affect the wine by reducing fruit perception, masking identity and muting typicity.

In a Rebo must trial, the document shows that LEVEL² SALVA™ applied at tank filling reduced the production of both 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG) by the end of alcoholic fermentation.

Can LEVEL² SALVA™ support lower-SO₂ winemaking?

This is probably the section you, winemakers, will love most.

While SO₂ remains a classic antimicrobial tool, its efficiency decreases as must pH rises, a situation that is becoming more common with climate change. At the same time, consumer demand for lower-SO₂ wines continues to grow.

To evaluate whether LEVEL² SALVA™ could support this shift, a Merlot trial in Bordeaux compared:

The control wine treated with SO₂ developed Brettanomyces and volatile phenols. By contrast, the wine treated with LEVEL² SALVA™ without SO₂ showed no detectable Brett and no volatile phenols, both at the end of MLF and five months later.

Important limitation: no remanent effect after fermentation

Once the cell walls of Brettanomyces are disrupted by the Brett inhibition factor, those cells cannot regrow. However, the Brett inhibition factor itself slowly degrades in the presence of ethanol, which means there is no remanent effect against new contamination after fermentation.

That is a very important nuance.

LEVEL² SALVA™ is designed to control Brett early. It is not a magical permanent shield. If new contamination occurs after AF or after MLF, the wine still needs to be protected by complementary tools and good cellar management.

Practical takeaway for winemakers

The biggest mistake with Brettanomyces is often assuming the fight starts in barrel.

In reality, if Brett is present on grapes or associated with specific vineyard blocks, the most strategic intervention point may be before fermentation even begins.

LEVEL² SALVA™ offers a precise early-stage bioprotection strategy by targeting Brettanomyces at harvest, during transport, or at tank filling. This early intervention can reduce Brett populations through MLF, lower volatile phenol formation, and in some cases even support a lower-SO₂ approach.

For winemakers facing recurrent Brett pressure, especially from known vineyard sources, this changes the conversation. Instead of asking how to clean up Brett later, the better question becomes: How early can you stop it?