ARS | Publication request: WHAT IS A HAUGH UNIT

Submitted to: National Egg Quality School Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 18, 2004
Publication Date: May 18, 2004
Citation: Jones, D.R. 2004. What is a haugh unit. National Egg Quality School Proceedings. p. 210-211.

Technical Abstract: Determining the interior quality of a shell egg can be complicated. There are both subjective and objective methods for making this determination. The Haugh unit is revered as the 'gold standard' for measuring interior egg quality. This method was developed by R. Haugh in 1937 and is based on the relationship of egg weight and height of the thick albumen. USDA Agriculture Marketing Service (AMS) have published specific guidelines for Haugh unit readings and egg grades (AMS 56.210). Haugh units are determined with the aid of a micrometer, balance, and level, flat surface (such as an egg break-out table). A break-out table can be useful during measurements because the mirror allows the operator to determine exactly when the micrometer comes in contact with the thick albumen surface. Due to current technology available, there are now manual and electronic methods for determining Haugh units.