A simple tip to deal with aggressive fermentation

Sometimes when brewing higher gravity beers, or if the wort temperature is too high at the start of the fermentation, the yeast can “go wild” and a very aggressive fermentation occurs. You will know that it happens when you see this kind of behavior a few hours after sealing the fermenter:

 

What happens here is that the yeast is “eating” the sugars very quickly and releasing a high volume of CO2. Think about it as if the yeast is gobbing down piles of beans and farting like crazy. All that CO2 needs to be released from the sealed fermenter, which is why we have a breather at the top.

The problem is when the CO2 volume is too high, a foam is created and will usually clog the breather, causing the breather to explode at some point and introducing oxygen back into the fermenter (which is not good). A very simple solution for a clogged breather is to replace it with an old school water cup breather: Stick a tube into where the fermenter fits at the top of the fermentation container, get a small container half filled with water and put the other end of the tube inside, next to the fermentation container. Make sure the water container is lower than the fermenter so water won’t move into the fermenter.

This kind of “crude” breather allows the release of a lot of gas while preventing any oxygen from entering into the fermenter. Don’t believe me? Have a look at what my coffee porter did last time:

So don’t let your wild and aggressive fermentation ruin your beer and stain your walls, just change the breather and let the storm pass.

Do you have any horror stories about out of control fermentations?