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The first time I visited master distiller Doug MacKenzie was at the old Great Lakes Distillery, which is now where Scott Buer works his Bolzano Artisan Meats charcuterie magic.

There weren't bubbling beakers puffing steam, but the large copper still and the stainless steel tanks gave the place a certain laboratory feel. And though he seemed entirely normal, MacKenzie's passion for creating spirits and his openness to try just about anything gave him a certain mad scientist vibe.

In his much larger current Great Lakes Distillery at 6th and Virginia in Walker's Point, MacKenzie has more room to tinker. But the success that funded the new home has come at a cost. With eight products in the Great Lakes/Rehorst line of spirits – and an endlessly changing series of limited editions and seasonals – MacKenzie's time and equipment is at a premium.

"For me as the distiller nirvana would be just to walk in every morning and saying, 'what do I feel like making today,' and who cares if it sells or not," he says as we stand near the still on a cool February morning and watch the still bubble away. Alcohol escapes out a pipe into a metal tank and water flows from a hose into a floor drain.

"You have to balance the mad scientist side with the business side. This isn't a hobby, it's how I make my living. I'd really like to have more time for it. but the time I do get to spend, those are some of my favorite moments here. You've got to educate yourself first and then figure out where you want to go. I think it's not a mad scientist thing for booze as much as you have to have a creative side.

While we talk, the still is cooking up a new product, a maple syrup rum. It is, unsurprisingly, the result of an experiment. When MacKenzie and Great Lakes owner Guy Rehorst floated the idea of giving a spiced rum a try, they wanted to localize it.

"We wanted to incorporate some sort of Wisconsin ingredient into it," recalls Mackenzie. "Obviously we don't grow sugar cane in Wisconsin, so that's out. So we said, 'let's try to add some maple syrup into it and use that as our base.'"

MacKenzie got to work testing and hit upon a formula that took him in a slightly different direction. First he distills molasses (that's what's going on during my visit), returns the resulting alcohol to the still and adds maple syrup and distills the mix again.

"You're not sweetening it necessarily, you're just pickling up the flavor of it," he says. "I did that experiment and everybody's eyes perked up and we went, 'well, this is really nice as it is, why would we want to mess with it?' It's the subtle maple flavor and kind of screams the Midwest, so left well enough alone."

The happy accident has two upsides. One, a great new Great Lakes rum. And two?

"It gives us the opportunity later on if we wanted to do a spiced rum or some sort of seasonal (rum)," says MacKenzie, who clearly keeps a running list in his mind of potential future projects.

MacKenzie, perhaps surprisingly, has a degree in architecture. Believe it or not, he says, those studies have real and practical applications when it comes to distilling spirits.

"My degree in architecture carries over into booze making in that you learn creative skills, you learn problem solving skills," he says. "The thing I got most from that degree is the process of creating. You brainstorm first, you get as many ideas down as you can and then you weed through. Then make sure before you execute that you've got a good solid plan in place."

Perhaps like an architect, too, MacKenzie never tires of tinkering an idea until it works. At the same time, he knows when he's gone down a dead-end path, and knows when to pull the plug. There are, he says, some things he's tried that seemed like good ideas, but, in the end, simply weren't.

"We distilled some cranberries into vodka – and cherries – which just don't transfer over very well," he says. "Those have to be done as a brandy. If you really want to get the flavor of the fruit, just infusing it into the alcohol and then redistilling it doesn't give you that. But you don't know unless you try.

"The first test batch of gin that I did, I couldn't even put it in my mouth. Just getting it to the nose was enough to say, 'nah, let's start over.' So then you've got to back track and say what went wrong, and figure out what you're going to do. That was like 20-some-odd test batches to get to what we finally had. And then you get lucky every once in a while. You try to reinvent the wheel and say OK, let's dial it back and get it a little bit more normal and then go back toward the crazy side again.

Even while he says he doesn't have much time to flex his mad scientist side these days, MacKenzie leads me over to the fenced in barrel aging area of the facility and shows me an unusual grappa that's sitting in oak, a whisky and a variety of other spirits that are, in effect, all experiments.

"We have some grappa that's been aging for a little over two years now," he says. "Normally they age grappa in Italy in French oak either that held wine or were new. We thought let's do an American version and put it in a used bourbon cask."

The finished product has a pleasing yellowish hue picked up from the wood and a sweetness borrowed from the bourbon-infused oak.

Last year's grappa, made from the pomace of different wine varietals (all come from Wisconsin's Wollersheim Winery), didn't sell out, so MacKenzie is trying a little barrel aging on that one, too. It may sit in wood for six months, a year, maybe two. He's keeping his options open to see what develops.

Upstairs in the new tasting room, the staff is infusing vodkas with a range of flavors for use at the bar: coffee, fruit, etc.

"The cool thing about the aged spirits it's not only what you're distilling, but you get the opportunity to experiment with different types of cooperage to pull different flavors out," MacKenzie says.

"So, that's always changing. We try different things. Even different ways you ferment you can get different flavors, too. That's the best part of this job: constantly learning, reading, studying, talking to different people and experimenting."

Fruit brandies – Great Lakes does pear and apple and others – always feel like experiments, he says, because nature's inconsistencies always force him to tinker to get what he wants.

"It's almost like everything's an experiment," MacKenzie says. "Once you decide you want to make a new product, you've got to fart around with it first. With the fruit brandies, you're a slave to the fruit. But that's the cool thing. When people buy a bottle of our vodka or buy a bottle of our gin, they're expecting a certain thing. So, you're ultimate goal with that is to make it as consistently as you can make. But with the small batch stuff and the seasonal stuff, you're going to get some that are ultimate fantastic and some that are ..." and, at that, he raises his hands as if to say, it's out of his control.