When we arrived at St. James's Gate, our names were taken by a security guard who drily informed us we were the first to arrive at the hidden away bar that evening – it turned out that he was just an incredibly sarcastic guy.

We entered The Open Gate Brewery at 6pm on a sunny Thursday to find it buzzing with folks enjoying after-work drinks in this repurposed section of the Guinness brewery.   

Experimental brews have been made at St. James's Gate for over 100 years, but only since last December has it been open to the public, where its reputation has slowly grown mostly by word of mouth.

In order to gain entry to The Open Gate Brewery, you'll need to book in advance - but believe us, it's worth it!

The bar's capacity is 150 but it's generally capped at 120, so that it never gets too full. This cut-off point means you don't need to worry too much about getting a seat, finding a place to put down your drink, or queuing at the bar.

The hidden gem has an industrial look to it – you are still in a functional brewery after all – with exposed pipes, vats, metal railings, and even the occasional late working brewer on show.

Antique brewery signs line the walls and barrels act as tables, in-keeping with the whole factory aesthetic they've got going on.

The Open Gate Brewery is for beer lovers, as it looks at the whole process from start to finish. We're talking beer specialists, experimental brews and plenty more.

There are currently eight brews available, such as their crisp Anniversary Pilsner, the creamy Guinness Nitro IPA, and the deliciously sweet Antwerpen Export.

Don't get too attached to any of them, however, because they're replaced every two weeks with the latest experimental batch.

Pints are €5 and half pints are €2.50, but we'd recommend getting a 'brew selection' for €6, where you're given a selection of four different brews (served in one-third of a pint glasses), moving from lighter to darker beers.

The barmen are constantly floating through the not-too-busy bar and they're happy to give you a lesson on the latest additions behind the counter. Also, ask them to let you try what's in the massive barrel in the corner.

This mysterious rum cask holds Antwerpen Export, infusing the beer with rum notes making it smoother and sweeter. It's ordinarily 8% – from this barrel, it's about 9.6%.

Should all that beer sampling put a hunger on you, they've also got a selection of great nibbles behind the bar, like mini tarts, giant pretzels, and sausage rolls.

Padraig Fox, The Open Gate Brewery's General Manager, said of the idea behind The Open Gate Brewery:

It's just about giving people a chance to taste some of the experiments our brewers have been trying out over the last couple of months. Some we will have an eye on launching further down the line, but the vast majority will never make it outside these walls.

The bar is open to the public on Thursdays and Fridays only, from 5.30pm to 10.30pm. It's €6 to book, but with that you also get your initial sampling tray.

If you don't want to miss out on these transient works of brewed art, get booking your next visit to the The Open Gate Brewery.