If you are in the middle of the boiling stage of your brew and you notice some foam on top of your machine, there is no need to worry. Read on to find out the reason for the foam and what you can do about it.
During almost every brew there will be some foam produced. Sometimes, however, there is an excessive amount which leads to some escaping from the condenser tube at the top of your MiniBrew and collecting on the top of the cover of the hop carousel. This often involves the steam condenser itself being ejected from the tube in the process. You can see the pictures below for clarification.
Foam is produced for a number of reasons, most commonly its due to the proteins in your malt. Excessive amounts of foam can form due to the properties of your malt such as which grains are being used. Even the same grains can produce a varying amount of foam from batch to batch. The water you use can also have characteristics that affect how much foam you see.
Once a certain amount of foam has been produced it affects the airflow within the keg which leads to more foam being created more easily, compounding the issue.
Luckily, when this does happen there is no need for alarm. You are able to wipe your hop carousel cover clean with a paper towel. When the foam production has reduced, you can place the steam condenser back in the tube and continue as normal.
The only real risk that foam can cause in rare cases is if you did not notice it for a while and it dries in place. If enough escapes it may settle into the carousel assembly and when it dries it becomes sticky and there is a chance it could affect the operation of the hop carousel. If this happens, the solution is to disassemble the hop carousel and then to spray it with some water before wiping the dried foam away.