Brewing is an ancient biotechnology process and requires foam to be generated in the production of products such as beer and cider. During the fermentation, the yeast in the process starts breaking down the sugars and starches. This metabolic reaction causes gas to be released (mainly carbon dioxide) at certain times during its production and this increase in gas release can produce lots of foam. This is also an issue in the distillation of most spirits.
Too much foam can create big problems with foam-overs and product loss, but in extreme cases foam has also led to fermenters exploding – this has occurred when foam blocked up the gas lines and the gas being produced could not escape. The foam can also be quite tricky to predict and quick to form, leaving the brewers with very little time to react. To allow for the potential of foam issues, it is common to see inefficient use of vessels as an increased headspace or ullage in necessary to accommodate any foam that forms, reducing the yield.
Antifoam is rarely added during the production stage, but it is often premixed into the media before fermentation begins in order to suppress foam formation during the process. Foam production can be managed by control of the process parameters or by recirculating the media though a spray bar. Either of these methods would be more efficiently performed by measuring the foam present with a suitable sensor.
Hycontrol’s highly versatile SureSense⁺ foam control systems have been specifically developed for measuring the thickness of the foam in a process, detecting foam-liquid interfaces and measuring liquid levels, ignoring the presence of any foam. The patented technology behind these systems originated from detailed research into foam control during pharmaceutical fermentation. Hycontrol points out that the special measuring sensors and control equipment have been designed specifically for foam control and are not modified level sensors.