Quality Control

As the size of brewery operations increased, the need for quality control procedures also increased. Brewers examine beer for contamination by microorganisms, alcohol content, clarity, flavor, and color. Alcohol content is checked by measuring the index of refraction or circular dichroism of the beer, or amount that a light beam is twisted or bent compared to pure water. A refractometer is simple in principle, consisting of a prism, a lens and a light source. Modern refractometers used in the brewing industry are small enough to be held in one hand.