Macro aeration during primary fermentation
1. Winemakers
generally underestimate, to a large extent, the amount of oxygen a red wine
needs during fermentation.
2. Macro
aeration helps maintain yeast viability and reduces the production of
sulfides.
3. Macro aeration may play a
role in the initiation of color stabilization.
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Most red
fermentations can use more, rather than less oxygen. This additional oxygen
helps minimize production of H2S, which can lead to
potential mercaptan problems later in the wine's life When
implementing the venturi (see following, make a hole in the top of the pumpover
system and attach a small nipple. Connect the nipple to a 3 to 6 foot air
intake tube. This arrangement is the simplest passive method for putting air in
intimate contact with fermenting must. Rack and returns, while effective at
removing stems and green seeds, are not effective at aerating a fermentor. The
out gassing of CO2 during the racking effectively
blankets the wine and minimize contact with air. Other methods
of putting air in contact with the must: opening a valve on the suction side of
the pump, or using an active valve that opens when the pump is switched on,
injecting compressed air or oxygen.
This type of venturi
works under most conditions. When combined with the check valve, it can be used
with most pumps and in a variety of positions. This system also provides
excellent aeration when racking a tank off lees. Learn more about
Mazzei injectors (new
window) |
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