Technique

Degassing Wine Techniques

It its simplest, degas means “to remove gas from.” While the practice can apply to any unwanted gas, we have a very specific objective in mind in winemaking. We mean to remove excess carbon dioxide (CO2) from a wine during production. Why we do this may be a bit more subtle than it looks at first glance. In deciding how to do it, the home winemaker has a range of choices from simple to sophisticated. And when to apply degassing will determine the ultimate success of the process and its effect on the wine. Carbon dioxide is produced during fermentation. Here is a look at the generalized sugar fermentation by yeast as presented by Yair Margalit in Concepts in Wine Chemistry: C6H12O6 – – – > 2CH3-CH2-OH + 2CO2 While there are many intermediate steps and side paths in the biochemistry of alcoholic fermentation, this shows the basic reaction. One six-carbon sugar molecule, like fructose or glucose, ends as two ethanol molecules and two carbon dioxide molecules. Since the sugar has a molecular weight of 180 g/mol and carbon dioxide