It is going to feel like the universe is caving in on you if one of your fermenters ever collapses from vacuum failure. That is why it is important to understand all the scenarios leading to vacuum failure and how to prevent them.

One common scenario is right after fermentation, when your fermenter is filled with carbon dioxide.  If you use caustic soda to clean your fermenter and do not have adequate vacuum relief, you run the risk of imploding your tank.  

Ashton Lewis, Master Brewer-in-Residence for Paul Mueller Company, demonstrates just how quickly vacuum failure can happen when you clean a fermenter full of  carbon dioxide with caustic soda.

After Fermentation

During fermentation yeast converts glucose into alcohol and carbon dioxide.  After you transfer your fermented beer to a bright tank you are left with a fermenter full of carbon dioxide.  

Ashton uses an empty milk jug full of carbon dioxide to simulate a beer fermenter.  

Clean-in-Place with Caustic Soda

To simulate cleaning-in-place, Ashton adds caustic soda to the jug and shakes it up.  There is a chemical reaction between the CO² and the caustic soda which creates a vacuum within the container.  

The jug is capped to represent a fermenter without the proper vacuum relief or a malfunctioning vacuum relief valve.

After only a short time the jug begins to crumple from the lower pressure inside the jug.  As the pressure continues to drop the weight of the atmosphere completely flattens the jug.

How to Prevent Vacuum Failure

To protect your tank from vacuum failure you can open the racking valve while you CIP.  It is also important to make sure your vacuum relief valve is large enough for your tank and that it is working correctly.  It doesn't matter how big of a vacuum relief valve you have if it is seized up from improper maintenance.  

Other scenarios where your tank can suffer from vacuum failure include hot CIP vacuum failure and overflow vacuum failure.  If you are looking to purchase a vacuum relief valve take a look at our .  Make sure your fermenters and bright tanks are fully protected by buying the right sized valve.