I am getting stressed by the orders piling up at my station on my first day as a Bewley’s barista when Goldilocks comes to the counter and nearly tips me over the edge. “I’d like a latte please,” she says. “But I don’t want it to be too hot. Or too cold. I want it just right.” She smiles expectantly.

I have about a million things to do and am about to ask her how I’m supposed to know what she considers “just right” when my mentor, Martino, steps in.

“That’ll be no problem, madam,” he says affably, and starts heating the milk for her coffee. As he uses his palm to gauge thee temperature of the milk, I make the coffee shot and remember all the things that can go wrong.

As part of my induction into the world of Bewley's coffee, my morning has been spent in the company of Marie Cassidy, the company's standards and training manager. She has warned me that even the finest coffee can be turned into a vile and bitter soup by an inexperienced barista. And I am an inexperienced barista.

“The cup is 50 per cent of the puzzle,” she says, before trying to teach me how to solve it. “Oxygen is the main enemy. So, once the coffee is ground in the cafe, it will only stay really fresh for five minutes. It doesn’t matter where you are ordering your coffee, it is very important that you hear the grinder, because silent coffee is not going to be fresh.”

In addition to the silent coffee, she warns me not to compress the grounds too much or too little into the filter holder. If the coffee is packed too tight, the water will struggle to percolate properly into the cup; if it is packed too loosely, it will flood through too quickly. Either way the end result will be bitter.

Then there is under-extraction, or not allowing the water to run through the coffee grounds for a sufficient length of time. The optimum length of time for the hot water to flush through the coffee in the filter holder is 24 seconds. Anything less, or more, will sour the brew.

I follow all the rules and the coffee is made. Goldilocks goes on her way. She seems happy enough. Martino, who is originally from Italy, has a rare moment to take a breath. He has been with Bewley's for more than six years and is now a supervisor in the flagship Grafton Street store. At his busiest, he could make more than 400 cups of coffee of varying degrees of complexity a day.

“We get a lot of tourists in here for sure,” he says. “But we also get a lot of locals. Bewley’s is part of what Dublin is, and a lot of people come in and talk to us about how they used to come here with their parents or their grandparents. I am Italian, so I should know all there is to know about coffee, but I have learned more here.”

You want a what now?
An order comes in for a cappuccino. I make it without much fuss, and, as I pause to admire my handiwork, which includes a topping that looks like a loveheart (kind of), another four orders land on top of me. Three Americanos and a latte. I get them over the counter. It's getting hot in here.

A woman asks for some class of ridiculous cold coffee drink with several words I have never heard before. I look at her in befuddlement until Martino takes over. Before I can say “it’s far from iced coffee you were reared, missus”, he is handing her what looks like a coffee milkshake.

It is not the most complicated concoction I will see being made this day. Elvis is responsible for that. Elvis Matiejunas is a barista trainer based at the company's headquarters, close to Dublin Airport, and he is practising his latte art when I walk through the door. I tell him I have never heard of latte art, so he gives me a demo.

He makes a cup of Joe – but it is no ordinary Joe. Once the coffee is brewed, he heats some full-fat milk and pours it into the cup. They he uses the foamy milk to draw a bird on to the coffee. He starts again. This time he draws a geisha girl on to the latte.

"In a month you could be a good barista if you worked hard enough at it," he tells me. I doubt it. I certainly could never be as good as Elvis, who is the Irish latte art champion and will head to Melbourne to represent Ireland at the World Championships next week.

After I meet Elvis, I bump into a very dapper Patrick Bewley. He is the grandson of Ernest Bewley, who opened Bewley's on Grafton Street, and the great grandson of Joshua Bewley, who founded the coffee and tea business and broke the stranglehold the East India Company had in Ireland more than 150 years ago.

“When I started out in this business, in 1965, instant coffee was only just coming in, and you couldn’t get any fresh ground coffee in shops other than ours,” he tells me. The company started selling coffee wholesale out of its Westmoreland Street branch, but its primary focus remained the cafes. Everything has changed now, and only a tiny fraction of its business involves serving coffee directly to consumers.

A booming business
And business appears to be booming. The Campbell Bewley Group trebled its profit in 2012 to €1.5 million following strong revenue growth at its UK and US divisions; turnover rose by 14.2 per cent to €97.5 million. While the company has experienced many tough times, the market conditions are making its life easier.

Two decades ago Ireland was a tea-drinking nation. The coffee bean is still behind the tea leaf, but it's catching up: the Irish coffee market is reckoned to be worth about €300 million annually, and we rank in the mid-30s of the world's coffee drinkers, consuming about 4kg each year – about 600 espressos each. A person who has a cup each day on their way to work will easily spend close to a grand each year on the stuff. With that kind of spend, it's important to make sure your coffee is just right. Anything else will be a jittery waste of money.


BEWLEY'S BARISTA BIBLE: COFFEE COMMANDMENTS

• Thou shalt not use stale coffee.

• Thou shalt not grind coffee in advance.

• Thou shalt serve perfect espresso every time, with a rich golden crema.

• Thou shalt not serve bubbly frothy cappuccinos, only silky smooth milk.

• Thou shalt treat thy espresso machine with tender loving care.

• Thou shalt always smile and greet thy customers to keep them coming back.