Written by James McCrorie of the Craft Brewing Association. With thanks to Brian Topham from Bairds Maltsters for checking the contents. (Reproduced with permission from the UKHB 1998 website)

On pages 8 and 9 of reference A, Graham Wheeler writes about measuring the colour of malts and beer. He writes "much of the stuff written in the home-brew press about beer colour has been technically flawed." It is easy to get our EBCs in a twist about malt colours because there are two different methods of measuring malt colours, both producing results expressed in EBC. Confused? Read on.

EBC stands for the European Brewing Convention which has agreed on various standards for use within the European brewing industry. One of these is a series of comparison standards for the colour of malt and beer. The colour of malt is decided by carrying out a specified trial mash and then using special equipment to compare the resultant colour of the trial mash with standard colour examples, usually known as discs as there are usually 9 different coloured glasses mounted on each disc used with this equipment. Alternatively, the colour is measured in an instrument called a colorimeter which compares the translucency of the wort to that of pure water. There is no problem so far.

The problem arises because the Institute of Brewing specified trial mash (reference B) uses a lower malt/liquor ratio than the EBC specified trial mash. Don't ask me why. This obviously produces a greater colour number for the same malt when the measurement is carried out by the EBC method rather than the IoB method. Confusion is caused by both methods expressing their results as EBC meaning EBC colour units. UK maltsters usually quote their malt colours as achieved by the IoB method, although maltsters involved in the export trade usually quote both IoB and EBC figures.

It may be of slight interest that these measurements are taken after a proper trial mash has taken place and that to obtain a measurement of coloured malts and adjuncts which, because they have little or no diastatic ability, cannot be mashed, a procedure is used where the coloured malt is mixed 50:50 with pale malt and the colour calculated from the result.

Now in reference A, I am afraid that Graham has motivated me to raise and try to clarify this anomaly. The following table quotes both the IoB and EBC method results as quoted, as a range, by a major British maltster together with the colours quoted for malts in pages 9 to 14 of reference A.

MALT TYPEIoB METHODEBC METHODQUOTED IN REF. A
Pilsner 2-3 EBC 3-4 EBC 2.5 EBC
Scotch Whisky Malt 2-3 EBC 3-4 EBC 2.5 EBC
Pale Malt 4-6 EBC 5-7 EBC not quoted
Mild Ale Malt not quoted not quoted 7 EBC
Vienna Malt 6-8 EBC 7-10 EBC 7 EBC
Munich Malt 7-10 EBC 10-15 EBC 14 EBC(light)
Amber Malt1 100-150 EBC 110-160 EBC 40-60 EBC
Crystal Malt1 140-160 EBC 160-180 EBC 100-300 EBC
Caramalt1,2 20-35 EBC 25-40 EBC 30 EBC
Chocolate Malt 900-1100 EBC 1100-1300 EBC 900-1200 EBC
Black Malt 1100 EBC(min) 1300 EBC(min) 1250-1500 EBC

Notes

  1. Maltsters have differing specifications for these malts. Typical examples are given.
  2. 'Carapils' is a registered trade name. Also called Carastan in North America.

In fact I don't really think we need to get too uptight on the subject of malt colours. Later processed in brewing, particularly boiling and fermentation, have their effects on the final beer colour. However, to a large extent malt colour = taste differences and as we are now benefiting from the importation of interesting German and Belgian malts we, perhaps, should be aware that there are two differing EBC colour measurement systems. As we are unlikely to import North American malts I won't bother you with ASBC and SRM colour measurement systems. If, after reading this, you start asking your supplier whether the colour of his malt is based on IoB or EBC trial mash methods, do not be surprised if you are moved to the 'clever clogs' category.

References

A. Brew Classic European Beers at Home by Graham Wheeler and Roger Protz.
B. Recommended Method of Analysis published by The Institute of Brewers 1991