Let’s explore ways to make continuous measurements with internet-connected devices.
Beer is a popular beverage around the world, but here in Grand Rapids, Michigan.
Fermentation is the key to making wine, beer and hard cider. We’ve found many breweries use a combination of computer systems and manual samples to do this.
One of the many indicators that quality assurance teams use to monitor beer is specific gravity. Specific gravity is a measurement of a liquid’s density in comparison to water. So, if a beer has higher specific gravity than another, it means that it has a higher mass given a constant volume. As beer ferments and converts those sugars to alcohol and gas, the specific gravity falls and the beer gets less dense, eventually approaching a point where there are very few sugars left and the fermentation process slowly stops.
Research uncovered some innovative ways to do this, but there were two specific approaches which found to be most promising.
- Monitoring Gas Flow Through the Airlock:
Many microbreweries already have a flexible hose that comes off the top of their fermentation tanks to direct gas into a 5-gallon bucket of water. Fitting that hose with a gas flow monitor would be quite simple and cost-efficient. This assumes that monitoring liquid flow into the fermenter or approximating the amount present would be straightforward.
- Taking a Pressure Reading:
The second was taking a differential pressure reading, that is, taking a pressure reading in the liquid at two different vertical heights. When you know the vertical distance between the two readings and the change in pressure between the two, it’s straightforward to compute a liquid’s density and specific gravity.
This is great because it can be accomplished with off-the-shelf pressure sensors and no other measurement is needed, such as the volume of liquid present.