The Colour of Beer

Steven Simmonds

Have you ever thought of the colour of beer?
People order a pint, just looking to cheer
Some like it golden, some like it light
Others like it dark, as black as the night

Behind all these differences, a great deal of thought
Goes into the colour of the beer as here taught
The key is the malt, be it golden or pale
Carefully selected to make the right ale

Pilsen malt is palest, barely coloured at all
For crisp golden lagers on this we would call
With only light kilning there’s no Maillard reaction,
No caramelization, so no colour extraction 

Other end of the scale, chocolate malt dark and rich
For making the beer all black as pitch
Intense Maillard reaction when malt is roasted
Leads to beer colour and flavour promoted

And while Maillard reactions in part are the cause
The exact chemistry of colour gives pause
Here in the lab we work day and night
To understand what makes a beer bright

The Science

This poem focuses on how the chemical reactions that occur during kilning or roasting of barley to produce malt contribute to the colour of beer. Maillard reactions are a chemical process that occur during the heating of food, where amino acids react with reducing sugars to produce a variety of reaction products which can give rise to flavour and colour in food. While the products of these reactions are diverse, and still being fully understood, melanoidins are known to be produced and are important compounds for the development of the brown colour of cooked food, or in this case malted barley. Malt used for lagers will be kilned at lower temperatures to try to prevent Maillard reactions and so produce a light, bright, golden beer. On the other hand malt used in darker beers, like amber ales, will be kilned at higher temperature to encourage Maillard product formation to develop the rich amber colours and accompanying flavours. For very dark beers such as stouts and porters, malt is roasted with temperatures reaching 235 degrees Celsius. This malt contains substantial Maillard reaction products which are, in part, responsible for the rich dark brown to black colour of these beers.

The Poet

Steven Simmonds (he/him) is a research scientist at the Laboratory of Food Chemistry and Biochemistry at KU Leuven, Belgium, and the coordinator of the Postgraduate Program in Malting and Brewing Sciences.

Next poem: the orange bird watches me, the whole time by Zixiang Zhang