Managing Malolactic Fermentation for Wine Style

Thursday, September 29, 2016
Malolactic fermentation is much more than a simple process. The ability of the malolactic bacteria, Oenococcus oeni, to affect wines in a positive way, both texturally and sensorially, is now being used to chase wine aromas and drive wine style. Common terms used to describe the positive effect of MLF on wine flavor are fruity, spicy, toasty, nutty and buttery. The butter aroma is due to the metabolism of citric acid, resulting in the intermediate metabolite, Diacetyl. To find out more about managing diacetyl in wine, click here.

The enhanced fruity notes can be attributed to the enzymatic activity of the bacteria strains (esterase and β- glycosidase), as well as due to the decrease in the herbaceous notes (due to acetaldehyde metabolism). Although there is a significant difference between the strains used and their abilities, we must also consider the matrix effect, in particular, the pH and ethanol concentration, as well as the grape cultivar and the timing of inoculation.

In general, an early inoculation (24-48 hours post yeast inoculation) should result in a fresh, fruity wine style with minimal buttery notes which may be desirable in whites, rosé and early to market red wines, whereas a sequential inoculation will enhance the spiciness, texture and complex fruit notes, while minimizing the vegetative and herbaceous flavors.

We have provided comprehensive aroma wheels (click to enlarge) to give users an idea of how each ML bacteria will affect aroma, mouthfeel, and flavor of the finished wine.

Enoferm Alpha™

Enoferm Beta™

Enoferm O-MEGA™

Lalvin MBR VP41™

Lalvin MBR 31