What is Guinness? Everything to know about the iconic Irish beer - Beer

Mar 16, 2026

Think St Patrick’s Day, and the first drink that comes to mind is likely a pint of Guinness. But what exactly is it? And why do people like it so much?

Guinness has been around since the 18th century, originating in Dublin, Ireland in 1759. While it’s always been a reasonably popular beverage, it was once seen as more of an ‘old man’s drink’. But in recent years, it’s undergone what’s been dubbed a ‘Guinnaissance’. The ‘Splitting the G’ social media challenge saw the drink’s popularity surge among young drinkers, while celebrities like Kim Kardashian and Olivia Rodrigo further upped its ‘cool’ factor through social posts and fashion statements.

What is Guinness?

Guinness is a dry Irish stout, and one of the most famous alcohol brands in the world. It even has its own Netflix show. You won’t see that happening for VB, no matter how many hard-earned thirsts it cures. Traditional Guinness ingredients include water, malted barley, barley, roasted barley, hops and a unique, proprietary strain of yeast that has been cultivated and reused for more than 125 years. A portion of the barley is roasted to 232°C, which is the temperature that triggers the Maillard reaction. This is key to Guinness’ signature dark chocolate and roasted coffee flavours. While it might look black in the glass, it’s actually a dark ruby-red colour, and when poured correctly, comes with a thick and creamy, long-lasting white head.

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How to pour a Guinness

The perfect Guinness pour is essential, as any dedicated fan will tell you. Unlike other beers, which are carbonated with carbon dioxide, Guinness is infused with nitrogen. Nitrogen bubbles are very small. So if you just quickly dump a load of Guinness into a glass, this will agitate these tiny bubbles, resulting in a huge mass of white foam and the entire local Irish population descending upon your house to stage an intervention.

If you order a Guinness at a pub, ensure that the bartender uses the traditional ‘two-part pour’. The first pour should be at a 45-degree angle, filling the glass about three-quarters of the way up. It should then be left for the nitrogen to settle, which is when you get that lovely dark base and clear white head. Then, for the second pour, the glass should be held straight up as the bartender pushes the beer tap away from them (which restricts the flow and adds less nitrogen) to slowly top off the glass, leaving a nice clean white dome of foam at the top.

A close up image of a pint of Guinness with the drink levelled at the mid point of the letter G on the glass. Source: X, @smivadee — Splitting the G. Source: X, @smivadee

What is splitting the G?

‘Splitting the G’ is a viral TikTok and Instagram trend where people take a large first sip of a pint of Guinness, attempting to make the level of liquid in the glass drop exactly to the middle of the ‘G’ in the Guinness logo on the glass.

What does Guinness taste like?

The roasted malt and barley in Guinness provide notes of dark chocolate, coffee and toast, which are balanced by a malty sweetness and a slight hop bitterness. The nitrogen in Guinness also creates the drink’s famously smooth and velvety texture.