COLOUR - Standard Reference Method (SRM) is the standard measure for degrees of color as related to beer and the grains that are used to brew it. Darker colors are associated with higher numbers. BITTERNESS - International Bitterness Unit (IBU) is the measure of hops’ contribution to a beer's bitterness. It can range from 0 to over 100. Beer bitterness is subjected to perception. What seems to be very bitter to some is only mildly bitter to others. Bitterness may also appear to be lower in the presence of residual sugar, carbonation and cooler temperatures. ALCOHOL - Alcohol By Volume ( ABV) varies according to different craft beer styles, ranging from around 3%to more than 20%.