Member of Tentamus - Visit
  1. Home
  2. Egg testing

Egg testing

Eggs belong to microbiologically sensitive products and must be tested regularly to protect the consumer.

Regulation (EC) 589/2008 sets deadlines for the grading, marking and packing of eggs. These serve to ensure the preservation of the degree of freshness and thus protect the consumer.  The regulation specifies that these steps must be completed within 10 days of laying at a licensed packing center. For eggs of the class “Extra” this applies within four days.  The minimum shelf life date cannot be set more than 28 days after laying.

Eggs can be contaminated with bacteria primarily and secondarily. Primary contamination occurs before eggs are laid, for example, by laying hens infected with salmonella. Secondary contamination takes place after egg laying, so that Salmonella, for example, enters the egg interior through feces on the shell.

To ensure that there are no bacteria in the products, microbiological testing of eggs is performed in our laboratories. These include testing for salmonella, E.coli, Campylobacter and spoilage agents.

  • Determination of the degree of freshness (determination of the Haugh units)

The Haugh unit (HU) is used to determine the degree of freshness of eggs. This method is used to determine the egg white quality and is based on the relationship between egg weight and the height of the egg white. For this, the egg is first weighed, then broken on a flat glass plate and the egg white height is determined by using a height gauge at a distance of about 1cm from the yolk edge. The Haugh unit can then be calculated from the egg white height and weight.


  • Determination of the yolk color (raw and cooked)

On the basis of the yolk color, it is possible to make statements about the feeding or possibly the state of health of the laying hens. The yolk color is determined with a yolk color fan.


  • Determination of the weight class

Eggs are divided into the weight classes S, M, L and XL depending on their weight. For this purpose, the eggs are weighed one by one and the weight must correspond to one of the following weight ranges: 

XL: ≥ 73g

L: 63 bis < 73g

M: 53 bis < 63g

S: < 53g


  • Checking for roll marks

By using UV light, it is checked whether rolling marks are visible on the shell of the eggs. In this way it can be possibly proven whether the eggs originate from cage rearing.


  • Air chamber height

The height of the air chamber can be used to make conclusions about the freshness of the eggs.


  • Measurement of eggshell thickness and strength

With this measurement, possible shell defects can be detected.

Complete range of services for eggs


bilacon supports you in all analyses related to your eggs in the course of in-house inspections or inspections ordered by the authorities. This includes:

Microbiological analyses


  • Bacillus cereus
  • Campylobacter (raw eggs)
  • Coagulase-positive staphylococci
  • Coliform germs
  • E.coli
  • EHEC
  • Enterobacteriaceae
  • Total germ count
  • Yeasts and molds
  • Hygiene germs
  • Listeria
  • Pathogenic germs and their toxins
  • Salmonella in the shell and in the yolk (raw and cooked eggs)
  • Spore-formers
  • Staphylococci
  • Spoilage pathogens

Residues and contaminants


  • Dioxins and furans
  • Mycotoxins
  • Nicotine content
  • PAHs
  • PCBs
  • Pesticides
  • Heavy metals
  • Veterinary drugs (Chloramphenicol, Florfericol, Thiamphenicol, Sulfonamides, Tetracyclines)
  • Trimethylamine

Chemical-Physical analytics


  • Colorants in dyed eggs
  • Labeling tests
  • Minerals and trace elements
  • Nutritional analysis
  • Sensory analysis
  • Vitamins

Others parameters


  • Yolk color
  • Single weight
  • Photo documentation
  • Freshness level
  • Haugh units
  • Inhibitor test
  • UV control



Call us, we will be happy to advise you personally


Tobias Stapper

Head of Microbiology bilacon GmbH

+49 30 206 038 370

Tentamus laboratories in your vicinity