Barleywine (III: Color)

BWJcolorRecipes for barleywines can be very simple. Before exploring how to formulate a barleywine recipe, however, it pays to look at two things — color and attenuation. In this article, we’ll examine color.



Barleywines are, of course, strong ales. Their color varies from amber to copper, with a few English examples being in the brown range. The color of barleywine wort comes from three possible sources, caramelization during the boil, Maillard reactions during the boil and the concentration of colored molecules derived from the malt. (These molecules would be formed by Maillard reactions or caramelization during the malting process.)


Caramelization is a browning reaction involving the breakdown of sugars. It turns clear or lightly-colored sugary solutions amber or brown and leaves the resulting solution tasting of caramel. Caramelization of maltose occurs at 356 °F (180 °C). For sucrose,  the temperature is 320 °F (160 °C). At sea level, wort boils at around 215 °F (102 °C), depending on its specific gravity. The presence of solids in the wort elevates its boiling temperature above that of water, 212 °F (100 °C).

So, caramelization is not going on in the bulk wort while it is boiled. However, in a direct-fired kettle — for example, in a stainless steel brewpot heated by propane burner — the metal can easily get hot enough to caramelize sugars, especially if the heat is focused in hot spots. If this is occurring in your kettle, it is easy to detect because the blacked wort sugars will stick to the kettle where they were scorched. Excessive scorching adds an unpleasant burnt taste to the beer. If you aren’t scorching your wort (and in almost all cases you shouldn’t be), little or no true caramelization is occurring in your wort.


Maillard Reactions

Maillard reactions are another type of browning reaction, involving reducing sugars (including glucose and maltose) and amino acids. Maillard reactions can occur at any temperature above freezing. Their rate is increased with increasing heat, but is inhibited by water. This is why boiling food doesn’t brown it as grilling (or any other method of applying dry heat) does. In addition, because water boils at 212 °F (100 °C), the temperature is limited in boiled foods. However, this is secondary. You can easily brown dry food under low heat to a degree you can’t with boiling water. Maillard reactions are what make the brown crust of bread taste different from the cream-colored interior.

Obviously, wort is an aqueous solution. However, even with the high concentration of water in wort, some browning via Maillard reactions occurs at boiling temperatures.



The overwhelming amount of color in a barleywine wort comes from the concentration of color-carrying molecules from the malt. The color added via caramelization or Maillard reactions during the boil is small compared to this.

When you mash grains, various color-carrying molecules from the malt become dissolved in the wort. (These molecules are produced during malting via Maillard reactions or caramelization.) When you boil the wort, the concentration of these molecules increases as water is evaporated from the wort. If you could somehow prevent any caramelization or Maillard reactions from occurring in the boil, your wort would still darken as you boiled it simply due to the increase in the concentration of color-carrying molecules.

For example, if you made a wort from only pale malt, initially by fully sparging a grain bed, it would be pale and somewhere in the vicinity of SG 1.045 (depending on your extract efficiency). If you boiled that wort until it’s gravity was around SG 1.080, the color of the wort would be amber — and the vast majority of the color change would simply be due to concentrating the color from the malt.


A Test for Color Pickup in the Boil

If you’d like to see the amount of color that Maillard reactions or caramelization is adding to your wort, there is a simple way to show this. At the beginning of the boil, note the volume of wort and take a sample such that you have 1 oz. of wort for every gallon of beer. When the boil is over, take a second sample using the same formula and in an identical glass. For example, let’s say you boiled 8 gallons of wort down to 5 gallons. You should have taken an 8-oz. sample of the pre-boil and then a 5-oz. sample of the boiled wort. Use the same kind of glass for both samples. Now,  dilute the boiled sample with water until it is equal in volume to the pre-boil sample. (Essentially, replace the water lost to evaporation in the boiled sample.) Finally, compare the color of the two.

In the absence of any Maillard reactions or caramelization — or any other color-causing reactions — in the boil, the colors should be identical. If the diluted sample of boiled wort is darker than pre-boil sample, that color pickup occurred during the boil. Obviously, this won’t work if you add anything colored to the wort during the boil, for example, dark candi sugar. In fact, in heavily hopped beers, some green color may be imparted to the wort by the hops. Likewise, it’s also possible for fining agents to strip some color from the wort (although we’d expect the amount to be minimal). And of course, the coagulation and sedimentation of trub could also alter the color of the wort. Still, the test above can be informative. It’s so simple that any brewer who routinely brews big beer should try it. As we’ll see, knowing where your color (and the flavors that come with it) comes from will help you make better decisions during recipe formulation).

The next article in this series focuses on attenuation and how it (and color) factor into recipe formulation decisions. 

Related articles

Handling Sugar Additions in the Kettle

Dark Grains




  1. the coagulation and sedimentation of grub???

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