Airlocks

Airlocks (or fermentation traps) are U-shaped devices that act as a simple valve allowing carbon dioxide to escape from wine as it ferments while simultaneously keeping oxygen and air-born bacteria from reaching the wine. Typically, sodium metabisulfite solution (instead of water) is placed in the airlock "U". This allows gas to escape from the wine (bubbling through then sodium metabisulfite solution), yet at the same time kills any harmful bacteria that can contaminate the wine. Fruit flies can carry harmful bacteria that may contaminate the wine. When a fly falls into an airlock full of metabisulfite solution, the "meta" will sterilize the bacteria and assuring that the wine will not turn into vinegar.

The airlock is inserted into a rubber stopper which is placed snugly into the top of the carbouy. When using the airlock, assure that:

• Adequate sodium metabisulfite solution is placed in the airlock. (Fill about half of the airlock with sodium metabisulfite solution.)
• The airlock is inserted snugly into the rubber stopper--do not allow for any gaps
• The rubber stopper is inserted snugly into the carbouy.

When inserting the stopper into the carbouy, assure that it is completely dry. Sometimes it is difficult to make wet stoppers to stay in the opening of the carbouy. Wet stoppers tend to want to "pop" out of the carbouy opening.

Airlocks are also extremely useful tool to indicate when primary fermentation has ended. Gas bubbling through the airlock will slow significantly once the primary fermentation is completed.