Instructions

1. Release it. During the early stages of fermentation, when significant amounts of carbon dioxide are produced, wine can be fermented in open vats. The CO2, being heavier than air, will create a protective layer that will prevent the wine from oxidizing. Later, when carbon dioxide production slows down, it becomes necessary to transfer the wine to closed vats. However, as CO2 emissions won't have ceased completely, a fermentation trap must be used. This valve will let the CO2 out of the tank, thus preventing excessive pressures that could cause it to burst, but it won't let the air in.

2. Monitor it. Amateur winemakers are occasionally overcome by the fumes in their tanks, and they have even suffocated to death. Carbon dioxide is heavier than air, so it will sink to the bottom of wine vats and wine cellars, and it is odorless, colorless and deadly. Even if you are not concerned about releasing CO2 into the atmosphere (the process is carbon-neutral, after all) you should keep the risk of CO2 suffocation in mind.  Working in a well-ventilated area is strongly recommended, as is the use of a CO2 monitor. Keep in mind that household smoke alarms may lack a CO2 detector; they are more likely to include a carbon monoxide detector instead. The use of a hand-held detector specially designed for use in breweries is well advised.

3. Re-use it. Carbon dioxide is frequently seen as a pollutant that must be controlled or disposed. However, CO2 can become an asset too, as it is necessary for a wide range of industrial processes. Winemakers and brewers that do not capture the CO2 they produce usually wind up buying CO2 tanks from someone else, as this inert gas is used to protect the wine from oxidation and to make beer bubbly. CO2 produced during fermentation can also be sold for industrial use, as it has applications in refrigeration, production of carbonated beverages, water treatment and production of dry ice among many others. Capture and storage their CO2 is widespread in industrial breweries, but some manufacturers are making relatively affordable CO2 capture devices more suitable for use in smaller wine-making operations. After being filtered and pumped into tanks, CO2 can be sold as an industrial input.

4. Capture and sequester it. Applying a carbon capture and sequestration process has the potential for making the wine-making process carbon-positive and environmentally friendly. The first stage, carbon capture, is quite straightforward, as CO2 can be captured directly from the fermentation trap. Keeping carbon out of the way, however, is more challenging. For instance, it must be injected back into depleted oil wells or saline formations. Because of the high cost of the process and the limited availability of fitting geological formations, carbon sequestration is seldom seen in wine making outside of academic proofs of concept.