Twelve months on they're ready to toast a year that's seen them win an award, release an album and gig non-stop.
"Getting your own headline gig at Tut's is pretty fantastic," says singer PJ Kelly, ahead of the group's show on Saturday night.
"We played there last year, on December 21, which was supposed to be the end of the world according to the Mayan calendar, and we had some fun with that on the night."
That gig marked the release of their debut album, which captured the band's varied sound. Many acts will claim to be unique, but Culann's complex concoction of folk and trad influences stirred with prog rock and heavy metal really does deliver something different.
It even impressed the man who produced the Who's Who Are You album, Jon Astley.
The producer and occasional singer, who's mastered albums by ABBA, the Rolling Stones and Eric Clapton, ended up mastering Culann's debut, after liking what he heard of them.
"We just emailed him, asking if he'd be interested, just chancing our arm," recalls PJ.
"He got back to us saying he thought the sound was quite different and he'd like to work with us, which was brilliant.
"He needed it for a certain time though, so for two weeks our guitarist was on the Red Bull and coffee diet getting the album finished.
It paid off for the quintet in the end, however, and they've had a great 2013.
PJ believes their recent success, including being hailed as "the Scottish Rush" in some reviews, is down to the band getting serious.
"It's not until you get a focused group together than things start to work," he says.
"We could probably have been accused of being lackadaisical in the past, and a wee bit lazy - in the last two years we've really knuckled down and tried to write good songs. When you put that effort in, it really helps."
Those two years have also helped the band develop their own sound.
Now the group - singer PJ, guitarist Greg Irish, bassist Calum Davis, keyboardist Ross McCluskie and PJ's brother Sean on drums - are happy with the varied styles the incorporate into their sound.
"When we started it was quite punky, but as you grow older you change," says the singer.
"We all listen to a lot of different things and we all have different tastes, so when you put that in the melting pot it can come to the boil. Me and Sean listen to a lot of folk, both Irish and Scottish.
"Some of us like Prog bands like Rush and Yes, and hopefully that diversity comes across in a good way."
Although regulars on the Glasgow gigging circuit over the years, the group are also fond of their roots in Irvine, where they all still live.
They believe the music scene there is on the rise, with more established bands visiting and a growing grassroots scene.
"There are a lot of good bands in Ayrshire, the whole scene is doing well," says PJ.
"There's My First Music, who put on the Dirty Weekender in Kilmarnock, and that's putting some focus and purpose into the place, getting more live gigs back here. The Grand Hall, in Kilmarnock, is putting on bigger bands, like the Darkness and Enter Shikari, and there's plenty of local venues doing things too. It's going in the right direction."
Evidence of that has come from Culann themselves, when they scooped the prize for Best Rock Act at this year's Scottish Alternative Music Awards.
The singer admits it wasn't a prize the band expected to win.
"I think we were quite surprised, we were up against some great bands, and they were all from cities like Glasgow and Aberdeen," he recalls.
"As they were from bigger places, we thought they'd have a bigger following voting for them, whereas we're from a wee town on the west coast.
"The support and backing we got from people here was fantastic, but it was still a surprise to win. There were some sore heads the next day…"
* Culann, King Tut's, Saturday, £7, 8.30pm.