A poured glass of Guinness next to a Guinness can with the caption 'Why Is Guinness Dark?'

Why Is Guinness Dark And How Dark Is It Really?

Guinness has been brewed in St. James’ Gate in Dublin since 1759, and thus has had plenty of time to create a large following. Though the flavor of this beer is one that is loved by many, it is the color that is probably this beer’s most prominent characteristic. There’s a reason that Guinness is also known as “the dark stuff”, after all. But what makes Guinness so dark? 

Guinness gets its color from the barley that is used in the brewing process. After being malted, the barley is roasted until it is black on the outside and dark brown on the inside. This gives Guinness its taste, as well as its almost black color. 

However, that certainly doesn´t tell the full story. Below, we´ll dive deeper into what causes the dark color of Guinness, as well as a comparison of different kinds of Guinness and whether or not this is the darkest beer out there!

Why Is Guinness Dark? (Explained)

Guinness is an Irish stout that is brewed using malted barley, hops, yeast, and water. But the real reason that Guinness is this dark is not because of the ingredients, but because of how they are prepared. The barley, in particular, undergoes a process that makes Guinness so dark. 

Sourced from local farmers, the barley is first malted. This means it is left to soak in water until it is germinated, after which it is dried with hot air. This process breaks down the cell walls, making it easier for the starches to be fermented. 

After the malting, the barley is roasted at 232 degrees Celsius in order to give Guinness its distinct flavor of coffee and dark chocolate. The roasting causes the sugars in the barley to caramelize, which means the beer no longer becomes sweet but has a strong bitterness instead. The caramelization also causes the outside of the barley to turn black, whilst the inside becomes a dark brown. This is what ends up giving Guinness, and other stouts, its distinct dark color. 

Surprisingly, Guinness isn’t actually black. In fact, it is not even brown. If you hold it up to the light, you’ll see this beer is actually a ruby red color. Although the barley is black on the outside after roasting, once used in the brewing process it causes the beer to go a dark ruby red. 

Is All Guinness Dark?

Not all Guinness is dark, but most are. Only Guinness Draught, Guinness Foreign Extra Stout, Guinness Smooth, Guinness Cold Brew Coffee Beer, Guinness Original, Guinness West India Porter, and Guinness Special Export are dark beers.

Guinness Draught is the most popular kind of Guinness and what most refer to when they talk about “the black stuff”. However, surprisingly, it isn’t actually black. Hold it up to the light, and you’ll find it has a ruby red color instead. 

Foreign Extra Stout was originally called West India Porter and is brewed with extra hops. The color is the same as you would expect from Guinness Draught. 

Guinness Smooth has the same taste as Guinness Draught but has a creamier mouthfeel. The reason for this is that they use nitrogen instead of CO2 to carbonate this beer. This results in smaller bubbles and a smoother feel. 

Guinness Original is, as the name suggests, the first Guinness beer ever and was the basis for every new variety. The color is the same as you would expect; a dark ruby red. 

Guinness West India Porter is a beer very similar to the Foreign Extra Stout. They have the same color and are brewed with extra hops. The former, however, has 6% ABV, whereas Extra Stout has 7.5%. 

The Special Export combines Guinness as you know it, with a slightly sweeter and more flavorful aftertaste, as you would generally expect from Belgian Beers. The color is still that same dark brown/black that you know. 

The last of the dark beers is Nitro Cold Brew, which combines coffee, caramel, and chocolate flavors with that of Guinness. The color is a dark brown. 

Other beers that Guinness makes that aren’t dark are Hop House I3, which is a double-hopped lager, and Baltimore Blonde, an American pale lager. Both are golden in color. 

Guinness recently started a campaign promoting ‘Guinness Clear’, but don’t let this fool you. It’s not some special kind of beer- it’s really just water. With this campaign, they want to promote responsible drinking and choosing a glass of water in between beers. 

Is Guinness The Darkest Beer?

It is true that stouts are the darkest beers available, which means Guinness is amongst them too. However, within the category of stout, we also have some sub-categories, some darker than others. 

Guinness is a dry stout, which is mostly brewed in Ireland. This is why they are also referred to as Irish stout. The color of dry stouts is generally a dark, ruby red. However, in the category of stout, Irish stouts are the lightest. 

If you’re looking for the darkest stout, Russian Imperial Stouts are your answer. 

In order to visualize and compare them, we use the SRM (or Standard Reference Method) to determine the color of a beer. The scale starts at 0 (which would be clear) and ends at 80 (pitch black, even when held up against the light). For reference, a pilsner like Heineken is around a 2 and is a very pale golden color.. 

Guinness, being an Irish stout, has an SRM between 25-40. Clearly, with a scale going up to 80, Guinness is still quite low.
However, Imperial stouts generally have an SRM of 50-80, making these the darkest beers available. 

As a result of its color, it is not surprising imperial stouts are generally more bitter and have more complex flavors. After all, the barley is roasted to such an extent that all the sugars are gone. Imperial stouts also have a much higher alcohol percentage. Whereas Irish stout has an ABV of around 4%, imperial stouts are usually more than 9%. 

So, although Guinness is a very dark beer, it isn’t the darkest. There are some varieties of Irish dry stouts that have the same color as Guinness, such as Black Rock, O’hara’s, and  Porterhouse Oyster Stout.

There are also varieties of Russian Imperial Stouts that are darker, such as Old Rasputin from North Coast Brewing Company, the Black Chocolate Stout from Brooklyn Brewery, and the Imperial Stout from Founders Brewing Co.