Abstract: Liquid lysine can be made with almost any particular specification that may be reasonably expected. A multistep process for producing lysine includes at least: fermentation, ultrafiltration, evaporation, and mixing. Depending upon the particular specifications that are to be met, at least two liquids may be taken from selected points in the multistep process. The lysine in these two liquids is concentrated to a desired level and then the liquids are mixed together and returned to the processing feed stream. The process may be applied to any amino acid which can be produced by fermentation.