Puscifer, a six-strong collective that started in 1995, have been touring "on and off" ever since the release of their third album Money Shot, and Keenan says they're in fine form. He promises something that's "not your average rock show".
"I'm sure you've seen photos online or read some things. I would encourage people not to read any of those things," he says.
He's equally cagey when it comes to the group's opening act. It's not a band - it's a group of Mexican luchadors called Luchafer who will perform in a wrestling ring.
"Just strap in and come see it," he says. "Sign on and enjoy the ride."
But Keenan's got a second appointment while he's here: he's one of the keynote speakers at the three-day Pinot Noir festival in Wellington. It's this that he's nervous about.
"It's alright," he says hesitantly. "It's going to be fun." What's he talking about? There's a pause. "I'm assuming wine," he quips, laughing at his own joke.
These days, "wine and music is intertwined," admits Keenan. From Merkin Vineyards in Arizona he produces a brand of acclaimed wine under the name Caduceus Cellars.
He's got a wine press upstairs and a music studio downstairs, and he can't, it seems, do one without the other.
"They criss-cross quite a bit. All things we have going on are integrated at this point, although the winemaking has a clock attached to it. There's a season, you have to be ready for it. Other things have to take a back seat during that period of time," he says.
"There's a lot of downtime during wine-making ... when the press is running I have time to sit and contemplate. I'll run down (to the studio) and do some things, run back up and reload the press, run back down, see where we're at, add some more."
Whether these songs he's working on relate to a long-awaited Tool album remains to be seen. Fans are still clamouring for the follow-up to 2006's 10,000 Days, but the Herald was asked to focus on Puscifer for this interview, and leave any questions about Tool aside. For the record, Tool has two festival slots confirmed this year: Boston Calling in May, and the Governor's Ball in June. This may confirm a new album is due around that time. Equally, it may not.
As Keenan knows from his winemaking addiction, good things take time. Tool definitely do, and it's taken Puscifer more than 20 years to make it to New Zealand.
Besides, Keenan is most animated when talking about his favourite topics these days - wine and food. He's opening a tasting room at Merkin Vineyards, and he's been working with chefs to make perfect pasta and "mess around with pestos".
"A lot of people have nut allergies," says Keenan. "They can't have pine nuts or pistachios, I've been using a lot of Parmigiano in the basil pesto to make sure no one goes into anaphylactic shock."
Cutting out the nuts? Surely Keenan would never do that completely.
Who: Maynard James Keenan
What: Puscifer
Where and when: Vector Arena, Sunday
