Achieving a reliable and successful malolactic fermentation (MLF) is a critical step for winemakers, especially when crafting sparkling, white, and red wines. Yet, despite its importance, MLF can be fraught with challenges: delayed or sluggish fermentation, spoilage risk, and unwanted sensory outcomes can all impact wine quality and stability. To ensure microbiological stability, flavour development, and overall wine excellence, understanding and controlling key parameters is essential.
Monitor & Adjust: The Foundation for Success
Regularly monitoring alcohol, pH, temperature, and total SO₂ concentrations before MLF is vital. Each parameter has ideal ranges, and maintaining these optimises the environment for Oenococcus oeni, the main bacterium responsible for MLF.
Target Temperature
Once alcohol exceeds 10% v/v, aim for a temperature between 18–22°C. This range promotes healthy MLF while avoiding temperatures above 25°C, which can increase spoilage risk and volatile acidity.
Balanced pH
A pH between 3.3–3.5 is ideal, low enough to inhibit spoilage microbes, yet high enough for MLF bacteria to thrive. Monitoring and adjusting pH ensures a stable fermentation environment.
Monitor SO₂
Before inoculation, ensure there is no detectable free or molecular SO₂. Measure total SO₂ for a complete picture of your wine’s chemistry, and keep additions below 50 mg/L to avoid inhibiting MLF. If SO₂ levels are too high, consider using an acclimatised starter culture such as ML PRIME.
Starter Culture Selection
For the highest success rate, use acclimatised MLF starter cultures. Matching bacterial strains with your fermentation yeast ensures compatibility and a smoother fermentation process. Our technical team is available to help you select the right options for your specific needs.
Set Your Wines Up for Success
By adopting these best practices, you can minimise risk, achieve stable, high-quality wines, and fully harness the benefits of malolactic fermentation.
For more information, contact a member of our Technical Team or explore our range of laboratory equipment and product solutions designed to support your winemaking journey.