A darkened corner of a Dublin whiskey bar, full glass in hand, loud rhythm'n'blues playing over the speakers. You would be hard-pressed to find a better place to meet Nathaniel Rateliff. Let's forget the fact that it is 2pm; this, after all, is the man who in his best-known song, SOB, yodels: "Son of a bitch, give me a drink."

Things were not always as cushy as this. The bearded, tattooed, hat-wearing musician, now based in Denver, Colorado, might have made one of the most invigorating albums of 2015 in the eponymous Nathaniel Rateliff & The Night Sweats, but it took trial and error to reach this point.

Rateliff (37) was raised in a religious household in rural Missouri and left for Denver at 18 to embark on missionary work. As you might have guessed, it didn't quite work out. "My first two years of trying to be a missionary kind of ruined [religion] for me," he says, laughing. "You just see the bad side of Christianity – or religion in general. I just stopped worrying about it. Once I started doing what I thought was best for my life and what I felt good about, I really woke up. I just kind of choose to be label-less, as far as religion goes, these days."

Having turned away from religion, he found himself a job in a trucking company in Denver. Then there was a stint as a gardener. “At some point, I quit the trucking company and started gardening because I knew if I didn’t, there was no end to that life. I knew I needed to quit, and it was scary because it was my comfort zone and I’d been there from the age of 19 till 29.”

Cassette tapes

All through his blue-collar career, music was a constant – although it was in the background. As a child, he soaked up the music of James Taylor and the 1970s folk his mother loved, as well as the Van Morrison, Eric Clapton and blues-rock his father listened to. "As a teenager, I fell in love with the oldies – '50s doo-wop, rock'n'roll, and then pretty much everything from the '60s on."

As a child, he taught himself first to play drums, then guitar. “I got my first drum set when I was seven, but I probably didn’t start to play seriously until I was 11, 12. I took lessons for a while but [my parents] couldn’t really afford it, so I ended up playing along to cassette tapes I found or the radio. I ended up doing the same thing when I learned how to play guitar: just listening to blues records and trying to mimic that stuff. It was the same thing with singing, too. I’d just listen to singers I liked and try to sound like them.”

His colleagues in the trucking company encouraged him to pursue music full time. "There were people at work who'd say 'Man, you oughta try out for one of them shows!' and I'd be like 'No f***ing way'," he laughs, referring to TV talent shows such as American Idol. "Nah. It's humiliating. The things that those mean motherf***ers say to people. I'd wanna go over there and put my thumb in their eye. 'All right, I got something to tell you, too . . .' "

But still, he wrote “all the time” during his working day. “Physical movement is a really good way to get creative energy flowing. It helps because my body’s moving so much I’m not being so neurotic or anxious about something. I used to carry a recorder with me, then they invented cellphones and eventually I had one of those. ”

Rateliff had been playing small-scale gigs in the US with his folk-pop band Nathaniel Rateliff and The Wheel, then as a solo artist.

The Denver scene was good to him, he says, because “mostly it was our friends and our community, so it was pretty easy to play a show and have people show up and be excited about it.”

Signed to Stax

It wasn’t until he formed a new band, Nathaniel Rateliff and The Night Sweats, that things started to happen on a grander scale. The incorporation of soul and classic rhythm’n’blues into his established storytelling style paid dividends, and he was signed to soul label Stax for the band’s first album.

“The content of the songs is the same,” he shrugs, explaining the “reinvention”. “As far as doing a different style, it definitely wasn’t motivated by anything more than, ‘I don’t know if this is really working out . . . let’s try this.’ It was something I wanted to do for a long time, and when I started to write the songs, it sounded that way and I was more excited about it than anything else I’d done. It was time to put out another record, so it was good timing.”

Along with acts such as Leon Bridges and Gary Clark jnr, he is often described as being part of a "new soul" movement.

“I’m fine with it, but it wasn’t intentional; I’ve had the songs for two years now,” he says. “I hope it’s more than a trend or a fad because I’ve never understood why soul and r’n’b is not everywhere.”

He has been on the road a lot since the album was released, which means a lot of late nights, travelling and partying.

“It depends on what you call partying. It’s kind of like when people ask ‘Do you drink a lot?’ I always say ‘Well, tell me how much you drink, and I’ll let you know’,” he laughs. “Clinically, I probably do. They say if you have three drinks a day, you have a problem – but who doesn’t? And it’s hard doing what we’re doing, just because you end up being in a place where there’s nothing to do but drink.”

He pauses, examining the end of his whiskey glass. There is more to Nathaniel Rateliff than the hard-drinking, hard-living, hard-playing soul man, he says.

“I’m pretty out in the open with everything. I love to dance, cook. I love playing music. I love screwing. I love eating. Pretty basic stuff, you know? I love to work hard, but I’m also lazy as f***. I love to swim laps. It doesn’t look like it, but I have to work out just to stay like this,” he says, smirking self-deprecatingly, raising an eyebrow as he gestures to his physique and drains the tumbler. “It’s all real, man. It’s all real.”

• Nathaniel Rateliff and the Night Sweats play the Olympia Theatre, March 12th-13th