PicoBrew did an amazing job at detailing the brewing process on their flagship automated brewing system, Pico. The in-depth user manual touches all of the main areas; however, as many home brewers know, many things can go awry. One roadblock many newbies will likely come across involves foam, also known as krausen, during the fermentation step (note: foam is NOT a sign that something is necessarily wrong – in fact, it’s a sign of healthy fermentation! The cause is likely due to not enough head room in your container). If you opt to use Pico’s “Fast Fermentation Method”, the manual mentions to simply wipe away any krausen that develops on the lid of the keg. However, if you opt to use Pico’s “Standard Fermentation Method”, the manual does not mention anything about foam!
Pico Standard Fermentation: Foam in Airlock
So, what is an airlock exactly? These small devices plug into the top of your fermenter and are used so that built-up CO2 can escape from your container while keeping the environment sealed and safe from contamination. As CO2 forces its way out of your container, foam can climb out as well and sometimes it will block airflow. If pressure builds up too much, the airlock or seal can actually come flying off – there are stories of beer on ceilings! I happened to be home at the time the foam started to appear, so I was able to combat it early on. Here’s a picture to show what mine looked like. The left photo is when I first noticed the foam, and the right photo is just 15 minutes later. It shows how fast it can block up.
If the foam you are experiencing is minimal, you can simply clean the airlock with some star san periodically. However, frequently unplugging the airlock can result in increased chances of contamination, since the hole will be open while you’re cleaning the airlock.
Blow Off Tube for Pico
The best way to combat foam during fermentation is to use a blow off tube. Blow off tubes are essentially an elongated airlock that helps drain expunged krausen into a bowl so you do not have to keep cleaning it. You can easily create one by simply attaching a half inch ID tube (best to use 3′ – 4′ length) directly to the bottom half of the 3 piece airlock included with the Pico. Place the other end of the tube into a clean bowl filled with a star san solution or vodka. Voila! Here’s a 6 second clip of the blow off tube in action on the Pico:
ALWAYS ensure your equipment is clean. Before you set up your blow off tube, make sure to thoroughly sanitize it with star san.