“That guy from the TV commercials!” That’s what they call him, either because they don’t know his name, or are by now too drunk to remember it. As the co-founder and chairman of the Boston Beer Company, he has appeared in countless Sam Adams commercials over thirty years. And, while this always-smiling man is a regular guy like you and me while walking the street, the second he enters a bar Jim Koch becomes a celebrity.

We met at a midtown Manhattan monstrosity called The Keg Room, where at least four people stopped Koch to say hello as we made our way to a table. One apologized for currently drinking something yellow and fizzy as opposed to a Boston Lager as we sat down.

“So many beer lists are poorly arranged, but this is pretty nice,” Koch noted. “A good mix of styles, not just a bunch of IPAs like most bars have nowadays.”

Seconds later, he learned that one of the two Sam Adams offerings on tap was their new IPA, Rebel. We ordered two, though there was another surprise: they arrived in shaker pint glasses, which “aren’t right,” he said. “You won’t get all the aromatics.”

He reached in his bag and withdrew a Perfect Pint glass, the shapely, angle-rimmed piece of glassware his brewery helped design back in 2007 and sent the waiter back to the tap. “I always carry one with me,” he said. “You’ll see…”

He was right – I did see. And then I saw a whole slew of beers almost magically appear on our table. Nitro stouts, sours, two big bottles from their Belgian-inspired Barrel Room Collection.  That’s when Koch snapped into full salesman mode, enthusiastically talking about Brewing the American Dream, his brewery’s micro-lending program which has helped over 300 food and beverage startups over the past half-decade. But as much as Koch likes to pitch his company, what the man really loves to do is drink beer.

He popped the top on Tetravis, the brewery’s version of a Belgian quadruple. I had never had it before and was blown away by its freshness and bursting dark fruit flavors, atypical of most quads, which are usually muted due to aging and oxidation. Noticing my pleased reaction, Koch quickly moved to uncork the second bottle, a Belgian stout named The Thirteenth Hour.

“I’m gonna be wasted before this interview is up!” I laughed.

That’s when things got dead serious for the first time all afternoon. Koch leaned in toward me, stared straight into my eyes, and whispered.

“You wanna know my secret? How I can drink beer all night long and never get drunk?”

In fact, I had always wondered that. Though this was the first time I’d ever formally met Koch, I’d “met” him in the past at a few beer festivals. Those sorts of events are always kind of Bacchanalian shit shows, with people imbibing dozens of beer samples in a short period and soon stumbling around large convention halls drunk of their asses. Brewers included. But not Koch, who I’d long noticed was always lucid, always able to hold court, and hold his own with those much younger than him. This billionaire brewing raconteur was doing likewise with me at 4 PM on a Thursday afternoon despite the fact we were both now several beers deep. So what was the secret?

“Yeast!”