Diagnosing Problem Fermentations

Diagnostic Key Mitigation of Post-Fermentation Off-Characters

Mitigation of Post-Fermentation Off-Characters

Many of the off-characters produced during aging are of a lasting nature and not easily removed from the wine. Small molecular weight volatiles may be removed from the wine using technologies such as reverse osmosis to remove components such as acetic acid. Spinning cone and other volatiles stripping techniques can also be applied but these may tend to strip the wine of desired components. If used correctly, these components can be recaptured and re-added to the wine.

Diagnostic Key Postfermentation Classes of Off-Character Compounds

Classes of Off-Character Compounds

Bacterial Production of Off Characters

Below is a table of the compounds produced by bacteria in wine and the type of aroma they produce.

LAB = lactic acid bacteria, AAB = acetic acid bacteria, Lb. = Lactobacillus, Oeno = Oenococcus, Pd. = Pediococcus

Off Aroma Compounds Produced by Bacteria in Wine



Sensory Effect

Diagnostic Key Mitigation of Fermentation Off-Character Production

Mitigation of Fermentation Off-Characters

If an off-character is found particularly after active fermentation has ended it may appear in the finished wine at the time of bottling. Some off-characters that may have appeared to have dissipated may return in the wine during aging or post-bottling. Thus effective mitigation practices need to be employed at the winery.