What makes Guinness taste so good? Nitrogen gas

Up to a third of Australians can claim Irish ancestry. This gives St Patrick's Day greater relevance on these shores beyond simply our shared love of the 'craic'.

So if March 17 may not have all eight million of us clad in green, dancing in the streets to The Wild Rover, surely it warrants a pint or two of Guinness in solidarity with our kin?

The flagship of the beer style now known as Irish Stout started out in the early 1800s as Dublin's answer to the dark brown porter beers that had taken London by storm.

But it wasn't until 1959 that Guinness fully harnessed the technology that made possible its creamy smoothness and long-lasting head.

Most beers get their carbonation from carbon dioxide. Guinness Draught was the first beer to use nitrogen gas or 'nitro', which yields tiny, extremely lively bubbles that give the beer its subtle carbonation and velvety texture.

It's the bubbles that make it

According to beer expert Johnathan Hepner, a Certified Cicerone and co-founder of specialist beer retailer Bucket Boys, Guinness today would not be Guinness without it.

"Nitrogen is very important to Guinness because it is the beer," he says.

"What people really love about Guinness is the mouthfeel and that subtlety that you get whenever you take away the carbon dioxide, because you get none of the carbonic acid – there's none of that bite, it's all creamy mouthfeel.

"Can you imagine having Guinness without the nitro? It wouldn't be anything like what you expected."


Nitro brews

The recent uprising of small breweries making flavour-oriented beers has opened up many new options for fans of dark beer and nitro.

Patrons of Sydney outfit Batch Brewing Company took to its Elsie The Milk Stout with surprising vigour, according to co-founder Andrew Fineran.

Now a mainstay in Batch's range, Elsie claimed 75th position in the GABS Hottest 100 Aussie Craft Beers of 2016.

A polarising drink

Fineran says this is remarkable, given the seasonality and polarising nature of dark beers, together with Batch's hyperlocal distribution, which is restricted mainly to Sydney's inner west.

"It's a stout, so it's a lower volume beer. It's really surprising that it made it so high. That means that the love for it must be that much stronger," he says.

"People really like it, especially Irish people. Every Irish person that's come in to drink the milk stout has said they like it better than Guinness!" declares Fineran.

That sweet nectar

The Hottest 100 coup recently emboldened Batch to package Elsie into cans dosed with nitrogen so that enthusiasts can enjoy its cascading head in the comfort of home.

As a milk or sweet stout, Elsie differs to Guinness due to the addition of lactose (milk sugar), which is not fermented by yeast, imparting sweetness that Fineran believes opens up new markets for dark beer.

A lighter option for beginners

"Adding lactose really just rounds it out and gives it that nice sweet finish, to my opinion it's really sessionable and it makes you want to sip it more," he says.

"In an age when we want more women to be drinking beer, a lot of women try Elsie and love it immediately.

"They look at stouts and think they'll be too heavy, but it's actually a good gateway beer for people to get into, because it's so different to their existing perceptions of 'beer'."

Honouring heritage

However, both Fineran and Hepner say they will always have a soft spot for Guinness, which sells 13 per cent of its entire annual volume in Australia during the month of March.

"Guinness is one of my favourite beers. I love Guinness, I really do," says Fineran.

American-born Hepner says the iconic dark beer was his first love, having grown up a country drenched in mass-produced, flavourless lager.

"If you notice, the thing that Guinness has over every other brewery is that the beer always looks the same in the pub as it does in the picture," he says.

True to form

Hepner says Guinness retains its signature white head not only because of the nitrogen content, but the fact that it is brewed with a percentage of unmalted barley.

"That head's going to hold and that's kind of the best part, it's like having the froth on top of your coffee," he says.

To mark the most important month on its calendar, Guinness has released a special edition beer from The Open Gate Brewery, the experimental facility at its home of St James's Gate in Dublin.

The limited edition

Brewed in the more robust style of a Foreign Extra Stout, Guinness West Indies Porter is brewed with more hops and higher gravity, to deliver a full-bodied and richly flavourful beer, with notes of toffee, chocolate and caramel.

Only 9600 of the Guinness West Indies Porter 500ml bottles are available through Dan Murphy's store in Australia during March, which means you'll have to get in quick if you want to get your hands on a bottle. May the luck of the Irish be with you!