It is really is up to the winemaker to decide to what extent
he or she will allow a wine to go through Malolactic Fermentation (MLF).
MLF is the transformation of malic acid into lactic acid by specific strains of bacteria during secondary fermentation.
Malolactic Fermentation is a series of metabolic effects
carried out by a group of bacteria that breaks down malic acid into lactic in
wines. Lactic acid is the acid profile found in smooth creamy milk. Mostly it happens spontaneously
throughout a wine’s life.
The theory though is… by depleting the malic acid early on;
the less chances there are of fermentation spoilage later.
MLF usually happens on its own and if not controlled can end
up with wine smelling leathery, sweaty and cheesy and even spritzy because of
extra carbon dioxide.
A lot of New World reds and white wines get smells like artificial
popcorn butter and desirable aromas that fit well together like buttery oaky
chardonnay that not only consumers like the taste of. The critics do too. This aromatic profile especially desirable in quality red-wines. It adds
a rounded feel, glycerin, even chewiness to the fruit to the wine when done right.
Just consider different food and combinations like Crab or Salmon and California Chardonnay. A Rich and Oaky Red Zinfandel and BBQ Grilled Steak...or a moist Mushroom Risotto with an Australian Shiraz.
From French Wine to California Wine and beyond; when you hear subjective wine sensory terms referring to feeling of fullness, viscosity and astringency the MLF has had an effect on the wine.
With that said Red Wines like Merlot, Cabernet Sauvignon,
Pinot Noir and almost any dry table wine that will be aged for more than 6
months for consumption at least a year after it’s first fermented are encouraged
to go through MLF.
In White Wines, Chardonnays makes good candidate for
malolactic fermentation for stylistic reasons. Other whites like Riesling are not
much… They are better when they retain their freshness, fruity zippy acidity.
So again, it’s up to the winemaker how much if any
malolactic fermentation is allowed in a wine.
How do they prevent Malolactic Fermentation?
MLF is usually arrested by chilling, adding Sulfur dioxide
(SO2) and filtering. Some winemakers want to discourage Malolactic Fermentation
at all costs. Even many consumers feel the same way, so they always keep the
wine cool and cellars under 62 degrees F. Malolactic Bacteria does not thrive
in cold temperatures, it flourishes less in high alcohol, High SO2 and the use
of fresh cultures.
That’s a strong reason for making and storing and monitoring
wine in cooler environments. It helps fight off potential spoilage.
Malolactic Fermentation has a lot of other things to it that
can affect it including racking, enzyme analysis, PH levels, different malic
acid powders, concoctions, egg whites, etc. Sometimes MLF bacteria is hard to
control and just doesn’t convert into lactic acid as expected.
When you drink a white. Ask if it has MLF. It might start an
What’s interesting is that sometimes-experienced winemakers just
use their ears during MLF you hear popping and burping and once the popping and
burping is done the bacteria is probably finished their job.