The Secret Adventures of a Beer Brewing Expert - OZY | A Modern Media Company

The Secret Adventures of a Beer Brewing Expert

The Secret Adventures of a Beer Brewing Expert

By Eugene S. Robinson

The bastions of beer
SourcePhoto courtesy of Heineken


Because you are what you drink.

By Eugene S. Robinson

In this occasional series, OZY takes to streets and neighborhoods across the globe to ask a simple question: “How was your day?”

Jan-Maarten Geertman
Zoeterwoude, the Netherlands

This morning I rode my bike to work for an early meeting at the brewery and missed breakfast, so I guess you could say I had beer for breakfast. Which is perfectly acceptable — I’m the product and process research manager at Heineken, or better yet, the brewery’s yeast expert. Yes, that’s a thing. In a nutshell, I study and experiment with yeast and the role it plays in the brewing process and the creation of new beers.

The pilot laboratory where I work is an offshoot of the main brewery in Zoeterwoude, just outside of Amsterdam. The main brewery is where most of our beer is brewed and then shipped to some of the 192 countries where roughly 25 million Heinekens are served each day.

The pilot lab is a pretty essential part of the company’s innovation and research departments. It’s where we brew our innovation prototypes; because everything is top secret, we give them cool code names like “Pioneer” and “Gotham.” Any day spent in the lab instead of behind my desk is an exciting day, and today was all about developing recipes for a series of wild lager brews — beer made using yeast directly from the wild, a beech forest in Patagonia, to be precise — as part of our Lager Exploration series.

Without yeast scientists like me, there’d be no beer. Can you imagine?

In the lab, I spend my days doing different experiments in developing new beers for the series. The lab is outfitted with a bunch of brewery equipment that lets our team make pretty much any kind of beer we could possibly dream of. I’m a scientist, so I tend to use more technical language, but in this case, I’ll just say that the possibilities here are endless — and that’s one of the things that makes my job exciting.

Most beers are made with a few basic ingredients. For us, we stick to the basics: water, barley and hops. Most beer lovers know that yeast, while not a main ingredient in Heineken, is a crucial catalyst in brewing that converts sugar into alcohol through a process called fermentation, and it plays a huge role in the flavor of any brew. Without yeast scientists like me, there’d be no beer. Can you imagine?


Before Heineken, my studies on yeast brought me to Ottawa, Ontario, where I led a team of yeast experts at Iogen Corp., redesigning and engineering yeast to enable it to make bioethanol from agricultural waste like corn stover and wheat straw. But when Heineken’s global master brewer, Willem van Waesberghe, called seven years ago with an offer to join the company as a senior scientist in yeast and fermentation, I jumped at the opportunity. Who could say no to working for one of the world’s largest brewers?

These wild lagers, though, are tricky because of the yeast — it was only recently found in nature, so [it] has never experienced life inside of a brewery fermentation vessel. Wild yeast is difficult to tame, but with our team of fermentation engineers, scientists, operators and product developers, we created the perfect brewing conditions for our new category. This has been the highlight — and probably the most challenging — of how I spend my time here. 

jan maarten heineken 1

Jan-Maarten Geertman’s magic.

Source Courtesy of Heineken

Today’s task was specifically to design the recipe that will let the wild yeast develop the flavors that characterize a wild lager. The first in the Lager Exploration series — we call it H41 — has a fuller taste, spicy with subtle fruity hints, than the traditional Heineken lager. This is when things get complicated and my years of training are put to the test. I must think through every possible variable: How much yeast should be applied? What fermentation temperature profile should be used? How much aeration is optimal? Which ingredients should we use? What are the best bottling conditions for this specific brew?

These questions may seem like minutiae, but it takes 28 days to brew a Heineken lager — twice as long as other lagers — so a mistake could set us back a month or more. There’s a lot of human resources that go into each experiment. Our fermentation engineer knows the ins and outs of our equipment and scaling the pilot — he’s the guy that makes sure we can reproduce our experiment brews in a real brewery. The product developer ensures that the recipe is made according to the right commercial specifications, like ABV. The operators are the ones who actually run the brews, adding the malts, the hops and the yeast to the process. And they’re who will eventually harvest the yeast and bottle the brew when it’s ready.

On days like today, when we gather in the pilot lab, the pivotal thought on everyone’s minds is that we are creating something that will give beer drinkers a new experience unlike what they’ve tasted before. And that’s something we’re extremely proud of. So, cheers to that.

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