It's 5.30am in Kilkenny and Fin Dwyer is up early for a day when he will set out to eat 40 potatoes.
Dwyer is taking part in an unusual experiment where he lives for a day on a pre-famine diet - consisting of spuds flavoured only with buttermilk, skimmed milk, seaweed, pepper and water.
He is the presenter of the Irish History Podcast, which is regularly in the top 10 of the Irish podcast charts, compiled by platforms such as Apple and Spotify.
In one of his most recent podcasts, Dwyer gave a running commentary on what it was like to live on the diet of rural labourers in the early part of the 19th century.
"It is incredibly monotonous - way more than I could have envisaged," he tells Review. "Even though I eat potatoes a lot, I struggled after 10."
The presenter interspersed his description of the diet with an interview with the food historian Regina Sexton, who offered insights into how people lived at that time.
Dwyer has been podcasting for a decade, but experienced a surge in listenership in the past two years. He has watched a medium that was once mostly a niche interest for a community of podcasters and their listeners reach a mass audience.
The growth of podcasting was confirmed in the past month when a Reuters Institute survey found that the number of Irish adults listening regularly to podcasts has grown to 40pc.
According to the survey, we are second in the EU for podcast listenership and in percentage terms, the medium's popularity is almost double that in Britain.
The under-45s are the most enthusiastic listeners, and 72pc of young people aged 18 to 24 said they had listened to a podcast in the past week.
Another sign of podcasting's mass popularity was Spotify's recent signing of the American podcaster Joe Rogan in a contract reportedly valued at $100m. The maverick interviewer and Ultimate Fighting Championship commentator presents his podcasts on video as well as through audio channels, and his pay packet is expected to be higher than that of any broadcaster in the world.
The type of podcasts that are popular in Ireland vary enormously and they often tend to be quite different in content to the most popular radio programmes.
In mid-June, during the week of the Bloomsday, a 1982 recording of the James Joyce novel Ulysses rereleased by RTÉ in 18 podcast episodes, soared to the top of the Apple podcast charts in Ireland.
Other podcasts that regularly feature in the top 10 include Eamon Dunphy's sport and current affairs vehicle, The Stand, The David McWiliams Podcast and a podcast presented by Blindboy Boatclub of Rubberbandits fame.
Dwyer's history podcast tackles topics in the kind of depth that would never be envisaged by most radio programmes because of their time constraints. He has presented lengthy series on the Great Famine, the Vikings and the Irish role in the Spanish Civil War, relying on donations from listeners as well as some advertising to fund the venture.
Dwyer is not surprised that history podcasts are popular. "I think podcasts work best with stories - and history is at its core about human experience and human stories," he says.
Podcasting is a natural bedfellow of radio, and some of the most successful shows are linked with radio programmes, or their presenters have experience as broadcasters. The TV presenter Louis Theroux was at number one in Ireland's Apple chart this week with a one-hour show that is also broadcast on BBC Radio 4.
The podcast charts tend to be dominated by male presenters. Among the exceptions is IT Galz, presented by Jenny Claffey and Lindsay Hamilton, which is billed as "a dose of cultural commentary and girl talk". Before the lockdown they sold out two live shows at Vicar Street.
A highlights show based on Sarah McInerney's Today programme on RTÉ Radio is also popular, and was at number 13 in the Apple chart this week.
RTÉ has only recently started focusing heavily on podcasting. Following the success of blockbuster American true-crime podcasts such as Serial, this year it produced its own six-part tailor-made podcast series, The Nobody Zone.
The podcast, co-produced by the RTÉ Documentary on One team and the Danish Third Ear productions, tells the story of Ireland's first serial killer, Kieran Patrick Kelly, who carried out his murders on the London Underground.
In September, the series returns with two follow-up episodes after new information about Kelly came to light.
Liam O'Brien, series producer of RTÉ Documentary on One, believes The Nobody Zone has been the most successful podcast ever to be produced in Ireland, with up to 2.3 million listeners.
O'Brien says the listenership for the podcast is different to that of the radio audience.
"We found that with The Nobody Zone, 97pc of the listeners were under 55, while the average age of listeners to RTÉ Radio 1 is 56."
RTÉ's documentary strand has seen its audience transformed since it started focusing on podcasting in 2009, says O'Brien. Back then, the documentaries had an audience of about 15,000 on a Sunday night.
Now, a documentary on RTÉ can achieve an audience of 250,000 on air, with a further audience of up to 150,000 as a podcast. Two-thirds of the podcast audience is in Ireland, and one-third is abroad.
As with Fin Dwyer's podcast, history tends to be popular, O'Brien says.
"If you can make history contemporaneous, you will rarely get a stronger storyline, and by and large these are ageless documentaries and listeners will come back to them."
Showing the diversity of the medium, two Tipperary comedians, Johnny "Smacks" McMahon and Johnny "B" O'Brien, have created a monster hit with an entirely different podcast, The 2 Johnnies.
The show regularly features at number one in podcast charts for the country, with a mix of jokes, banter, songs and the sort of stories of sexual misadventures that would never be allowed on most radio stations.
Before they became full-time entertainers, Johnny McMahon was a butcher and Johnny O'Brien a hurl maker.
"We are friends and we play for the same GAA club," O'Brien says. "We did a few local fundraisers as a comedy act, and then we started to be The 2 Johnnies. We started doing videos on Facebook, did a nationwide stand-up comedy tour, and then started podcasting."
Before the pandemic struck, the pair were due to perform at the biggest-ever live podcast at Cork's Marquee in front of an audience of 4,000. The sold-out show has been postponed until next year. They have toured all over the world with live podcasts.
"I had loved listening to podcasting for some time," McMahon says. "The free-flowing style where you don't have to answer to anyone suits us. Our podcast has all the bells and whistles, it's all-singing and all-dancing with music as well as stand-up."
"The main boxes for us to tick is that we give people a laugh," O'Brien says. "There is some debate, we're talking about things you wouldn't hear on the radio, and it's a lot of fun."
As well as earning revenue from their live shows, the pair carry advertising on the podcast and sell merchandise including 2 Johnnies caps, mugs and customised Tipperary shirts.
The 2 Johnnies have had to adapt their act during the pandemic as they can no longer perform in front of a live audience. They now charge listeners for a second weekly podcast.
During the pandemic, the pattern of listenership has changed. Some podcasters report a fall-off in listenership at commuting time, but listenership has increased at other times.
Eamon Dunphy, whose podcast is attracting up to one million streams a month, says: "We thought that the audience would go down in the lockdown, but actually the numbers have increased."
The show started out as a soccer podcast but has moved on to cover current affairs issues such as Brexit, Donald Trump and the pandemic.
"For me, doing a podcast is partly born of frustration," says Dunphy. "These stories are nuanced and detailed, and you can't do them in seven or eight minutes.
"On a programme like Morning Ireland, they are always hurrying people up. I don't know if they ever get anything in an interview other than sound bites.
"We can give a subject room to breathe. People are hungry for good, intelligent, uncluttered content. At the end of a podcast, people should have a good command of the facts."
Last Friday, I put out my 131st consecutive weekly podcast. Through storms, holidays and a pandemic lockdown, I haven't missed a single episode of The Big Tech Show since it started two-and-a-half years ago.
But it's only now that I'm starting to understand what my show actually is and how to present it.
The thing about podcasts is that they're completely random. There is almost nothing a Blindboy Boatclub episode has in common with the theatrical murder mystery series West Cork. Neither resembles the New York Times's Daily podcast in any way, or that of Spotify's superstar recruit Joe Rogan.
Yet one or more of these will often be cited as a generic response in answer to the question: "Do you listen to a podcast and, if so, which one?"
When I started mine, I knew only that it would deal broadly with tech-related issues.
It quickly became apparent to me that this was the least of what would become important in trying to make it work.
Style, tone, timing and - above all - respect for the listener's time soon became the main issues.
Was I to aim for a diary, a sermon, a structured interview or something else? Would it be best to position myself on equal footing with whatever guest was on? Or ostentatiously aim to get out of his or her way, newscaster style? In some ways, these correlate uncomfortably closely to questions around the strengths and weaknesses of my own character. Can I sustain a robust exchange of questioning with a person? (Sometimes.) Am I interested enough in someone for a compelling audible interview? (Too rarely, I have found to my own dismay.) Most frightening of all, am I myself interesting enough to be anything more than a wooden wannabe reading a series of cue cards and stumbling through intros and outros? (I still don't know.)
If there's one thing I have definitely learned, an overriding principle that guides almost everything from subject matter to tone and timing, it is this: don't waste the listener's time.
If you're not funny, don't try to be. If you're not charming or clever, don't try that either. And for God's sake, get to the point quickly.