What is it? What's the benefit?
What wines benefit from it?
How is it started and controlled?
Do I need to know(understand) to make champagne?
Anybody know any good references to help?
An excellent description of Malolactic Fermentation (MLF) can be found in
section 20 of the FAQ for this newsgroup at:
Basically; MLF is not a fermentation at all; but is instead a process
whereby a bacteria culture is introduced into the wine which converts harsh
malic acid into milder lactic acid. MLF is probably called a "fermentation"
because CO2 is one of its byproducts. Chemically; here is what happens when
MLF takes place like:
MALIC ACID LACTIC
H-C-H PLUS CO2
H-C-COOH Bacteria---------> H-C-COOH
To facilitate MLF a culture of Leuconostic (sic) bacteria is added to the
wine. The bacteria synthesizes the malic acid (harsh "apple" acid) into
milder, creamier lactic acid and CO2.
The benefit of MLF is a less harsh, milder tasting wine.
In terms of wines to target for MLF, as Don has pointed out in the faq,
Pinot Noir tends to benefit. Additionally; most wines made from grapes
which are grown in very cool climates (especially reds) will benefit from a
In terms of whites, there are split camps on the subject. Chardonnay is an
excellent example; many robust "California" style Chards are send through a
MLF, while the great white Burgundies are not.
I would recommend experimenting (send a portion of your wine through the MLF
& see whether you like it over the non-MLF batch).
A culture of the bacteria can be purchased from your local wineshoppe (I
think that it costs about $8.00 US). I know that Lalvin makes such a
culture. The culture is usually introduced into the fermentation cycle near
the end of the primary fermentation (when both SO2 and *** are at
tolerably low levels).
In terms of the wine's acidity; MLF should reduce your TA by 0.1%-0.3%.
However; the perceived reduction in acidity is substantial.
With respect to Champagne; I don't know if MLF is recommended, but I would
doubt it as high acidity is regarded as a beneficial characteristic of a dry
Hope this helps.
"Wine is sunlight, held together by water..."