Famed distiller Dave Pickerell changed the way Americans drink whiskey.

On Wednesday, November 1, he passed away in San Francisco. The cause is still unknown. He was in the city for the annual WhiskyFest event.

After spending 14 years at Maker’s Mark, he left to run his own consulting company and set up or consulted on countless distilleries around the world. He also mentored the new generation of craft distillers.

In recent years, he would spend most of the year on the road splitting time between his main projects, WhistlePig Whiskey in Vermont, Hillrock in Ancram, New York, and the old-fashioned distillery at George Washington’s plantation Mount Vernon. He also served as the distiller for Metallica’s new whiskey brand Blackened. The last time we spoke, while filming a video for a WhistlePig in Vermont for a campaign that the Daily Beast is creating, he was extremely excited to be working with the heavy metal band. Metallica was equally excited to be working with him. In fact, Dave’s name is prominently printed on the bottle of whiskey—not Metallica’s.

Lars Ulrich, Metallica’s legendary drummer recently told me about how impressed the band was with Dave. “When Dave was presented to us as a potential collaborator, it felt like he was sort of, it may sound cheesy, but the Metallica of that particular world,” Ulrich told me. Last April, Dave even did a whiskey seminar at Ulrich’s house for his friends and family. “All of my intellectual friends are sitting there bombarding him with questions. I was just sitting back in the corner watching this thing unfold and watching the master at play and enjoying it.”

While Dave wasn’t usually subtle—he was prone to wearing a broad-rimmed black felt hat and on occasion a Boss Hog getup, including a three piece white suit, to promote WhistlePig’s Boss Hog bottling—he was very often the smartest person in the room.

He had grown up in what he described as abject poverty and had gone to West Point, since it was free and offered him a chance to study science, which he loved. He played on the school’s football team and later taught there before getting a degree in chemical engineering from the University of Louisville.

Over the years, Dave and I did a number of different panels together at industry events, including a memorable one at Tales of the Cocktail about starting a distillery. While his personality could certainly fill a football stadium and he could have no doubt have handled the panel himself, he allowed the other panelists to speak and share their opinions. But no matter how difficult or technical a question we got from the crowd, Dave would have the answer. He was my go-to guy when the conversation stalled and was always ready with a story or a funny quip. He was the life of the party, which seemed to surround him like a bubble no matter where he went.

He was incredibly generous with his time and his knowledge. His enthusiasm for making spirits was evident immediately from anybody who ever met him. His advice and counsel to craft distillers around the world effectively took a small spark of creativity and created a movement that changed not only what we drink but how we make it. Dave helped refine the craft movement and gave its spirits a professionalism that allowed it to actually compete against and sometimes best the old standards.

While he made bourbon at Maker’s Mark, his real passion was straight rye whiskey. He was one of the few people in America who believed that it could one day be a major category again like it had been during the 1800s. His was proud of the technique he developed for controlling the mountains of foam produced by the fermenting of the notoriously difficult grain.

When we last met we talked about the Kentucky Bourbon Hall of Fame and I could tell he truly desired to be a member. We all knew it was only a matter of time before he was honored. I’m just sorry he won’t be there when it surely happens.