This wintery time of year is more closely associated with darker and richer beers, their fuller body more comforting when a less refreshing beer isn’t as desirable. Styles such as stouts and brown ales are defined by their colour, but why are different beers different colours? Beer by definition is alcohol made from sugar extracted from malted barley, and it’s this key ingredient that shapes the colour of a beer.

Malted barley, or malt as it’s abbreviated to, is made from barley that’s grown around the UK. It’s one of the few ingredients in UK beer that you can be pretty sure comes from this country, and with good reason; our malt is arguably the best in the world. Barley starts off life in the field as one of a few types of barley; normally malt growers use a couple of varieties that are harvested at opposite times of the year to ensure consistent output. At the point of harvest, barley destined to be used to make beer enters the malting process. I won’t go into massive detail on this (there’s entire books about this), but essentially the barley goes through a process of hydrating, dehydrating, and then kilning, in order to create brewery-ready malt. It is this step that defines what type of malt the barley becomes, the control is entirely in the hands of the maltster.

Each maltster generally offers a wide variety of malts, each treated to a set of specifications during processing that promise the brewer a certain outcome. Each set of specifications has a name, so no matter what malt company a brewery uses, they can understand what each type of malt is offering without having to read reams of data. Malts are split into five categories: base malts, highly kilned malts, crystal malts, roasted malts, and speciality malts. Each of these categories has varieties within them that offer more flexibility.


Base malt: the ‘canvas’ of the beer, comprising the majority of most beers. They are pale with mild flavours such as biscuit and bread.

Highly kilned malts: these are slightly darker than base malts, and add a sweet/raisin flavour.

Crystal malts: these are red/brown in colour and offer sweetness and body, and rich caramel flavours.

Roasted malts: these are dark brown/black and offer sooty/coffee/chocolate flavours.

Speciality malts: these are malts often derived from other crops such as wheat and oats. They tend to offer low colour and flavour, but aid head retention and mouthfeel.

When you’re drinking a darker beer, you’re tasting and seeing a lot more malt character than you will in most other styles of beer. The brewer will use different malts as tools to insert different facets to the beer. I’ll use our coffee breakfast stout Aguacatones as an example:

Extra Pale Maris Otter: light in colour, provides a nice malt base and lots of fermentable sugar.

Chocolate Malt: very dark brown, adds a flavour like pure cocoa.

Flaked Oats: adds a silky and full mouthfeel with very low colour.

Wheat Malt: provides very low colour but aids head retention.

Black Malt: very dark black, adds an intense roasted flavour.

Crystal Malt: a deep red, adds sweetness, body, and a nice caramel flavour.

To use a slightly strained analogy, making a beer recipe is similar to making a cake. No matter what cake you make, you’re nearly always going to use mainly base malt (the flour), and then accentuate that cake with other strong ingredients, but in a lesser amount (cocoa powder, icing, jam, sprinkles etc.). The difference between a stout and a lager malt-wise isn’t as great as you think, they are both made from very similar malt bases, but the stout will trade out roughly 20-30% of the base malt for more impactful malts to enhance the flavour and colour. 

Beer by definition is malt based, and this key ingredient is far more flexible than you’d think.

For further reading please enjoy John Mallet’s book Malt: A Practical Guide from Field to Brewhouse.