Mark Grist: High master of the poetry slam

He became an internet sensation as an unlikely rap-battle victor last year. Now he wants to win over Edinburgh

Former teacher Mark Grist stands his ground at the Edinburgh Fringe (Fraser Band)

You may not recognise the name Mark Grist, but you might just know who I'm talking about when I say "the teacher in that rap battle". In November last year, the suited-and-tied 30-year-old triumphed over a young grime MC with his virtuoso tirade in a Brixton nightclub. When a video of the unlikely victory was posted online, it went viral. Come February, it had racked up more than one million views and "Rap fan sir" was making national headlines. "I couldn't go out for two weeks. It was not unusual for me to get 1,000 tweets in a day and my Facebook maxed out. I even had some girls come and chat to me in a nightclub," he says in disbelief, "but I was mainly feeling a bit tired, really."

Not everything was so charmed for the coolest YouTube sensation since Fenton the Labrador. First, there was misreporting to contend with, not least the assumption that his opponent, MC Blizzard, was also his pupil. Then there was the matter of his lyrical content, his especially lewd variation on that rap battle staple, the mum joke, not sitting well with his day job, running creative writing workshops in schools. And, finally, there was the "bullying campaign" directed at his supposedly "cocky" 17-year-old Mancunian opponent by the media and others. "Blizzard is a musician with a great work ethic and the basic message was 'Ha ha ha, look at this teenage boy getting a taste of his own medicine', and that was not what it was about at all."

More typically known as a performance poet, Grist has channelled these anxieties, and more, into Rogue Teacher, an Edinburgh festival show that sees him toying with preconceptions once again. Those expecting an extension of that YouTube moment will be disappointed by the conspicuous scarcity of raps and insults. Everyone else, though, will likely be moved, humoured, and provoked by a show that employs verse and storytelling to reflect on Grist's formative experiences, romantic, professional and otherwise. Does he see it as a coming-of-age story? "A coming-of-age-a-bit-too-late story," he smiles.

Indeed, there is something of the big kid about its idealistic, puppyishly enthusiastic creator. He grew up on the Shetland isle of Unst, whose barren landscape he credits for his literary leanings: as well as reading voraciously, he would come home from primary school and pen "these ridiculously lengthy ballads", complete with knights and monsters. His teenage years saw him rocking out in a band, however, and he returned to writing poetry only in his twenties. By that stage, he had moved to Peterborough to teach English after studying at the University of East Anglia.

"In Peterborough, there was nothing like the cultural scene there was in Norwich, so some friends and I set up an [open mic] night called A Pint of Poetry. That gave me a reason to write a poem every month, so I just used to write things about my experiences in my job."

Grist makes for an impassioned educationalist, and a key section of Rogue Teacher deals with his frustrations during his five-year stint in a secondary school. On the one hand, he worked at a relatively progressive institution that allowed him to

pursue his own quirky teaching methods involving poetry and rap. But on the other, he found himself ground down by the callous and unimaginative nature of the system as a whole. The show's angriest poem is directed at a composite colleague character with no time for "fuck-up" pupils; another offers a riposte to a chief examiner he heard mocking a pupil's offbeat poetry analysis at a conference.

Nor is Grist a stranger to harsh judgement himself. After quitting to become a full-time poet in 2010, he decided to take a creative writing MA at Goldsmiths College, London. On arrival, one tutor broke it to him that his poetry, as it stood, was simply not good – and that he needed to curb his rhyming habit. Given that he had sacrificed financial stability and a promising career for his vocation, this was crushing news. In retrospect, though, he says such criticism was inadvertently the making of him. "I probably did the MA because I wanted to be a page poet – there's still a perception that having a written collection is the highest point you can reach – but what I learnt is that my poetry is not designed to be read."

But if the spoken word has long been misunderstood as an art form – hovering between poetry, comedy and theatre – that is slowly changing. This is the first year it has merited its own section in the Edinburgh Fringe programme, while performers such as Luke Wright and Kate Tempest have been gathering mainstream followings. Grist, too, has been doing his own bit to popularise the genre, for a while as one half of the spoken-word duo Dead Poets.

Formed with MC Mixy, whom he met at a poetry night in 2008, the odd-couple double act started "as a bit of a social experiment", he says. "We wanted to see if he could be classed as a poet and people would consider me as a rapper." Now the two perform everywhere from schools to clubs, swapping roles and verse styles. "It's about creating new audiences for both art forms."

And so back to that November night. In the final section of Rogue Teacher, Grist deals with the uneasiness he felt over his performance, relaying an apology he sent to his opponent's slighted mum. But if that provides the show with a nice, redemptive climax, Grist's off-stage take on the matter is rather more ambivalent. "I still ultimately don't really regret anything I've done," he says, adding later that, if anything, "the production leans on the whole thing of Mrs Green a bit too much … it wasn't her battle, and I thought [bringing her into it] was disrespectful, but as far as the creativity of it all goes, I was fine with that." (And her response? "She's a wicked woman … I think she finds the whole thing funny and unusual.")

More worrying for him was the reaction of the pupils at his old place of work, who started chanting some of the ruder lyrics back at him when he returned to film a spot for Channel 4 News. "I just thought, oh, hang on ... as a teacher, I have to restrict myself."

Similarly, while he has subsequently pledged to watch his words, he adamantly refuses to criticise other rap-battlers for their linguistic choices, misogynistic or otherwise.

"There is a real debate about what is offensive going on within battling, but, as is often best in the classroom, if people are allowed to work things out for themselves, it's more of a lasting lesson than condemning them." That stance might seem mealy-mouthed were it not central to Grist's fervently non-judgemental ethos: "As a teacher, your students may write or say things that you don't think are morally correct but you don't judge them for that, you focus on the creative side."

Those hoping to see Grist in combat should get in quickly: he thinks he may have only five or six battles left in him. And with TV and film projects mooted, as well as an audio book and teen novel in the works, he may yet transcend his 17 minutes 12 seconds of fame. But before he retires from the ring, there's one person he would dearly like to teach a lesson. "If I could battle anyone it would be Michael Gove – he is making [teaching] feel as much like punching yourself in the face as he can." Over to you, Mikey.

'Mark Grist: Rogue Teacher' is at the Underbelly, Cowgate, Edinburgh (0844 545 8252) to 26 Aug