Fermentation Locks

Fermentation locks or air locks are fitted into a stopper that fits on the top of your fermentation container. Even red wines that are fermented in a large, open-mouthed container, will be transferred to a 3 or 5 gallon glass carboy and fitted with a fermentation lock. The locks are designed in different ways, but all hold a column of water between the wine and the outside air. The lock in the photo is shaped something like a sink trap. Water is trapped in the middle allowing the gas to escape from the wine but not allowing outside air to get in. Yeast, mold and bacteria can become trapped in this water. Care should be used when removing fermentation locks from carboys so that contaminated water does not leak into the wine. It is important to keep the fermentation locks clean and sanitized during the fermentation.