Blow By

blowby.

    In homebrewing, a single-stage fermentation method using a glass or plastic carboy in the mouth of which a plastic hose is fitted, curving down over the edge into a pail of sterile water. This method allows the primary fermentation to blowout all the froth and carbon dioxide while preventing air from coming into contact with the fermenting beer, thus avoiding contamination. After one to three days the beer is either transferred to a second carboy or left in the first one for the secondary fermentation process.