Uwe Daebel knows what makes the perfect beer for Munich’s Oktoberfest: Cold and in your hand.
But because Daebel is the engineer for Paulaner, the Munich-based brewery, who for decades has overseen Oktoberfest beer-flow management, he’s obsessed with the tight logistical ballet of the technology that enables it.
"It’s got to be a cold beer until the very last gulp," said Daebel, standing outside Paulaner’s Festzelt, or party tent, in jeans, running shoes and a traditional red Bavarian vest.
Munich’s annual Oktoberfest, which runs through October 6, sees a staggering amount of beer. Almost 8 million litres, enough to fill more than three Olympic-sized swimming pools, flow from 28 000-litre tanks and into the bellies of roughly 6 million revellers. To keep the beer under 2 degrees Celsius and maintain the fizz of 4.5 grams of carbon dioxide per litre, Daebel has enlisted Siemens and the internet of things.
Munich-based Siemens, once one of Europe’s largest engineering conglomerates, is in the midst of transforming itself into a much smaller company that specialises in machine automation. It handles beer flow for three big beer tents, including the Paulaner Festzelt.
It usually takes about seven hours for beer trucks to fill the three tanks. But for Paulaner, Siemens situated them in a single location, where they can be refilled in a little more than 90 minutes. A pipeline runs from the tanks into the various stations where the beer is filled into waiting glasses.
Monitoring the operation is Siemens’s internet of things software, called Mindsphere. In a backroom, mounted beside steel pipes, is a 15-inch tablet where Daebel can monitor the condition of every beer station. In emergency situations, Daebel can also oversee the system wherever he goes on a laptop he keeps in a backpack.
On the tablet, a graphic representation of the entire beer system is laid out. Little wooden barrels smile wider the more beer flows through them. Daebel checks the numbers. The beer is at an acceptable 1.8 degrees, and the pressure is steady at 1.14 bars. That’s much more uniform than in the past.
Before the system was centralised, "every barkeeper used to have their own philosophy on maintaining pressure," Daebel said. As beer left the tanks, they’d keep the pressure up using bottles of pressurised carbon dioxide beside them. But everyone pressurised differently, and in some cases, barely at all.
"The carbon dioxide just goes to the dogs then," Daebel says.
Now, large tanks of liquid carbon dioxide, supplied by another Munich-based company, Linde, stand in another room, and as beer leaves the tanks, Siemens’s software automatically pumps the carbon dioxide into the mix to maintain pressure.
The result is that the system can handle 12 000 litres of beer per hour. The demand is usually far less than that, with the exception of the opening Saturday, when guests can’t seem to get enough.
Down to the temperature
With the help of the data, brewers can predict demand, according to Stefan Scharpen, the sales head at Siemens Digital Industries, who started the project with Paulaner.
It comes down to temperature. If the tanks are overfilled there’s a lot of beer at the end of the night, that beer will be warm by the next day. If too much warm beer is left sloshing in the tanks, that elevates the temperature of the next day's batch. And because warmer beer flows more slowly, that can affect how quickly the beer travels from tank to stein.
"Then the bartender suddenly needs 2.5 seconds per litre, instead of 1.8, and that's a problem," Scharpen said.
All the gadgetry happens away from guests’ eyes, in locked rooms above and away from the celebrations. The revellers, for the most part, don’t know - and don’t care - about the intricate network of pipes, sensors and pressurized gases that delivers their beer.
Sitting in a box with her friends, Maria Rasp, 21, drinks a standard 1-litre beer. The Munich native said she attends the festival every year.
Her requirements: The beer needs to be cold, and it needs to be filled right up to the litre line so that she’s getting her money’s worth. But her topmost concern is similar to Daebel’s.
"The only thing that matters," Rasp said, "is that it gets here fast."