Practical Winery
65 Mitchell Blvd, San Rafael, CA 94903
phone: 415-453-9700 ext 102
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November/December 2007
In the future, Lyon wants to see better phenolic testing, and he is experimenting with Lysozyme in order to delay MLF in order to utilize microOx additions a bit longer.
The investment in a microOx system can be substantial for a winery with many tanks like Scheid Vineyards (Greenfield, CA). With the labor required to set up and monitor each tank, all winemakers and winery owners need to consider the return on investment of this involvement. Scheid Vineyards installed a Parsec multi-unit system capable of feeding O2 to 120 tanks.
MicroOx is employed on select wines designated for the bulk wine market. Dave Nagengast (winemaker) says, "Feedback from the bulk market indicates that the microOx process is definitely adding value to our wines."
Nagengast has used microOx for five years. He has tried different systems and selected Parsec for the recent winery expansion due to the controls and flexibility built into the system.
MicroOx is used post-secondary fermentation and SO2 stabilization on bigger, more phenolic reds such as Cabernet Sauvignon, Merlot, Syrah, Petite
Sirah, and Petite Verdot. Some custom-crush clients request it, and it is used, as noted above, for some wines headed to the bulk wine market. In both cases, the wines can be whole lots, or portions intended for blending. The purpose is to soften the tannins and improve color intensity.
Duration of the use of microOx is largely determined by weekly monitoring of the free SO2 and DO and regular tasting. Researchers (Waterhouse and Laurie, 2006) noted that the O2 tends to collect in layers. It is important to collect samples from low in the tank, or in larger tanks, to circulate the wine to be sure of an accurate sample. During microOx use, tank temperatures are kept at 58° to 60°F. Typically, oak inserts are used in conjunction with microOx, rather than wine going to barrels.
MicroOx is continued until tasting indicates that the tannins have softened and the color is appealing. Stopping microOx will stop further aldehyde production, and allow the reactions to go to completion.
The Cypress line of wines from J. Lohr (San Jose, CA) is sourced from Central Coast grapes. Made in a fruitforward style, the wines are primarily tank-aged. Winemaker Jeff Meier uses microOx, often in conjunction with chips or inserts on the Cabernet, Merlot, Shiraz, and Chardonnay wines in that line.
Chardonnay sometimes gets a hyper or macro-oxygenation dose; done to soften high phenolic juice prior to fermentation. The juice gets 9 ml/L of O2 for one day, allowed to settle overnight, then racked off juice lees to start fermentation. During fermentation, 0.5 ml/L O2, along with untoasted oak chips, are added for sweetness.
MicroOx is also used at J. Lohr for high tannin, and/or over-extracted Cabernets and Merlot in the Estate Series. The rate is between 5 and 80 ml/L/month done primarily between primary fermentation and MLF to soften tannins. Chips or inserts are often added to reduce herbal
Westec OxBox
Westec OxBox is comprised of one electronic flow meter and four individual mechanical flow controllers for each tank.
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