We report that the lees in salmon fish sauce consist of Tyr and Phe. The concentration of free L-Tyr (2.0 mM) was almost same as the saturated concentration (2.4 mM) in water at 20 degrees C. This result shows that lees are formed by Tyr precipitation due to its saturation in the sauce. (C) 2011, The Society for Biotechnology, Japan. All rights reserved.