Sometimes you just don’t know what you’re missing until you start looking. Just as that’s often true in life, so it is in brewing. In the case of Andrew Klosinski and his team at the MillerCoors brewery in Milwaukee, new discoveries were made when they began searching for a better way to manage fermentation, which is one of the most critical steps in making beer. Read about what they found.
During fermentation, yeast is added to wort – a carbohydrate and fermentable sugar solution – within a reactor vessel where the yeast breaks the sugars down into ethanol and CO2 over the course of several hours. The CO2 that’s generated is collected to carbonate the beer and move product around the facility. Success in the beer market revolves around quality and consistency, but fermentation is a biological process, so every batch has the potential to have a unique fermentation profile. When it came to CO2 collection, Klosinski knew there was room for improvement in terms of understanding exactly what was going on inside the fermenter with each brewing cycle. Traditionally, the brewery has triggered CO2 collection according to time and temperature differentials, but these are typically not exact indicators in practice. To remedy this, Klosinski called his local Emerson Field Sales representative, Larry Wavrunek, who recommended installing Emerson’s Rosemount™ 3051S Electronic Remote Sensor (ERS) on the brewery’s fermentation vessels to detect headspace pressure and the level of the liquid beneath it.
After conducting a series of tests on one of the brewery’s vertical fermenters, Klosinski found that in many instances, Plant Operations was initiating CO2 collection well after sugar-to-ethanol conversion had begun—sometimes many hours afterward—which meant valuable CO2 was being wasted.
The test results suggested that measuring the pressure of the headspace inside the fermentation vessel would provide a more accurate signal that CO2 was being released. The ERS provides differential pressure readings without the need for complicated hardware or capillary tubes that are susceptible to measurement drift. Within just a few days the devices had been shipped, installed, and were producing data that could be used to gain better insight into the state of fermentation inside the tank.
This improved awareness will allow for more efficient CO2 collection, which by Klosinski’s estimate could translate into annual savings of more than $200,000 in CO2 once the transmitters are installed on all 28 of the brewery’s vertical fermenters. It will also make it easier to prevent rupture discs from blowing out due to over pressure, which typically cost $65,000 a year.
The project is also expected to enable substantial benefits in terms of capital avoidance and increased throughput. By using the pressure readings to infer the density of the liquid to detect when it has arrived at terminal gravity, operators will know when fermentation is actually complete, rather than waiting until a fixed process time. This means that the brewery can conduct quality testing and clear the fermentation tanks for the next cycle sooner, which could translate into a production increase of 400,000 barrels per year. That’s about 9.6 million more cases of beer.
By the sound of it, the decision to take a closer look at this particular problem should leave quite a few of MillerCoors’ thirsty customers satisfied for years to come.
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