|Seal the secondary fermenter using the sanitized airlock and rubber stopper. Be careful not to force the rubber stopper in so far that it falls into the beer; this does happen.
The beer is now ready to be placed in a cool dark place once again. The beer now completes fermentation and begins to mature. Secondary fermentation at room temperature lasts for one to two weeks. Any longer and off-flavors can be produced from dying yeast.