phone:415/479-5819 · fax:415/492-9325
WINEMAKING
|
Tannat [the pre-
dominant variety of Madiran, France
were microOx started],
dominant variety of Madiran, France
were microOx started], Petit Verdot,
Malbec, Barbera, and Ruby Cabernet)
and occasionally Chardonnay. For the
reds, color and fruit development,
palate fullness, diminished reductiveness,
and improvements in the vegetal
characteristics are the reasons for
using microOx.
MicroOx is done in tanks with oak
inserts, regardless of whether a wine
will go to barrels or not.
"At times, we will microOx Chardonnay
to help control the reduction
potential when ageing sur lie in stainless
steel tanks," explains Ziemann.
"Our goal is to age on yeast lees, and
using small amounts of microOx with
lees stirring can be beneficial in keeping
the wine in the positive (sweet
aroma) direction. Not all white wines
react in this way, you need to be very
careful."
Both the Oenodev and Parsec
equipment are used and the advantages
of both systems are still being
evaluated. MicroOx is done right after
fermentation and continued through
MLF. After MLF, with the rate of oxygen
reduced, microOx is continued for
only two to four weeks.
Along with regular tasting, the dissolved
oxygen is monitored daily,
especially with the higher rates used
early in the program, to determine the
amount of O2 needed. Regular monitoring
of free SO2, VA, pH, TA, malic
acid, and temperature is also done.
Some aldehyde formation is
desired, so SO2 is added only after
MLF, and is adjusted to 20 ppm free. In
the early stages of microOx, temperatures
are kept at 18°C (64°F) and then
lowered to 14°C (58°F) after MLF.
Ziemann is very aware of the increase
in dissolved oxygen as the temperature
drops.
Deciding whether a wine should
receive microOx is often difficult,
especially when the parameters are
marginal. Ziemann uses the following
to make determinations:
Sugar - close to dry, no higher than 2 to 3 g/L,
pH - 3.7 or lower, |
Color - visual,
Tannin - winemaker taste, Reduction character - winemaker taste.
Ziemann emphasizes that microOx,
like all winemaking technology, needs
to be incorporated into the total winemaking
program. He and his team
started with small experiments in
1998, and then put it into limited production
in 1999. Experience gained
each year has been invaluable.
He notes with the improvements
that, "the equipment is much easier to
use
|
being computer-based/webbased.
One can monitor more lots in
much less time."
He sees the use of
microOx as a continuum and will be
examining other varieties to see if they
might benefit from microOx.
While not normally noted, wine
ageing and enhancement of the
wine/food paring are also considerations
for the use of microOx.
Ziemann's experience, while still
rather limited, is that microOx doesn't
detract from either age worthiness or
wine/food paring.
|
Five-tank remote controller for the Parsec micro-oxygenation system.
|
||