Well I woke up this morning and I got myself a beer

A week ago Jesse and I left our homebrew in his closet to complete its primary fermentation. A sanitized tube was left in place to handle the discharge of foam from the top of the carboy. This is how we left it:

The foam at the top is caused by the fermentation process which creates both carbon dioxide and alcohol. The foam also serves another purpose, it protects the brew from germs and wild yeasts in the air. As the primary fermentaion neared its end a couple day s ago the foam collapsed back into the brew. Commercial breweries sometimes take steps to remove the foam before it can fall back in, but that's a pretty risky proposition for the homebrewer, fooling around with the beer at this point presents to big a risk of contamination.

With the protective layer of foam gone though we had to do something to protect the beer. So Jesse pulled the tube out of the carboy and insereted a sanitized stopper and fermentation lock. Here's a picture:

The fermentation lock is basically like a curvy straw, shaped like an S on it's side. The lock is filled with water so that air from the outside can't get in. However as the secondary fermentation process continues Carbon Dioxide that is produced in the carboy. As the carboy fills up with Carbon Dioxide pressure builds until a bubble travels through the lock and releases it. In this closeup picture you can see the water inside the lock and the explanation will hopefully make a little more sense.:

This Saturday we'll be bottling our brew - look for some more pictures and descriptions then.