Blow-off tube
Revision as of 00:36, 7 October 2017 by Uncle Jesse (talk | contribs)
A venting tube exiting a bung and either fitted with a valve or seated in a sulfite solution. When a demijohn or carboy is used as a primary fermentation vessel, the blow-off tube allows foam formed during the initial, violent period of fermentation to escape without disturbing the integrity of the airlock.