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A Beginner’s Guide to Egg Grading and Handling

29 January 2025

Egg grading of table (eating) eggs describes the process in which eggs are classified and categorised based on their production standard, shape, weight and hygiene level. Egg grading and marketing are regulated under UK legislation to ensure quality, safety, and transparency for consumers. Compliance with these requirements is essential for all egg producers and sellers in Scotland.

Many contract producers will send their eggs to the company for which they are contractors for grading/stamping. Independent producers will need to invest in these themselves, unless they are exempt (see below).

Egg biology

From www.chickens.allotment-garden.org

Figure 1. Diagram of a hen's egg (source: www.chickens.allotment-garden.org)

Understanding egg biology helps to ensure that we handle and store the eggs in a way which maintains their quality and hygiene standard. Eggs in storage and in packaging should always be stored pointy end down with the air cell pointing upwards and the chalaza pointing downwards nestled in the packaging. This ensures that the yolk stays centred, reduces the risk of bacteria entering the air cell and increases the shelf life of the egg.

Egg classification

Eggs are classified in two categories, class A and class B. Table 1 below reveals the inspection standards for each class of egg.

InspectClass A Standard
Cuticle• Normal Shape
• Clean
• Undamaged
Shell• Normal Shape
• Clean – foreign matter in not permissible, washing is not allowed
• Undamaged
Airspace• Height < 6mm
• Height < 4mm for eggs marketed as ‘extra’
• Stationary
Yolk• Visible on candling as a shadow only
• Without clearly discernible outline
• Slightly mobile upon turning and returning to a central position
White• Clear and translucent
Germ cell• Imperceptible development
Smell• Foreign smell not permissible

Class B
• Any egg not meeting Class A criteria
• Cannot be sold for human consumption
• Can be used by food industry for processing

 

In addition, class A eggs are sorted by weight and labelled as:

  • Very Large (XL): 73g and above.
  • Large (L): 63–72g.
  • Medium (M): 53–62g.
  • Small (S): Below 53g.

Identifying eggs - Egg stamps and packaging labels

Apart from some circumstances that may exempt the poultry keeper from identifying eggs (see “Exemption from egg grading” below), Class A eggs must carry the following information:

  • Stamp on Each Egg:
    • Farming method (0 = Organic, 1 = Free-range, 2 = Barn, 3 = Caged).
    • Country of origin (e.g., "UK").
    • Producer’s unique registration code. You may also have a stamp that demonstrates what accreditation scheme you are part of, e.g. the Lion stamp, if relevant.

 

  • Packaging Labels:
    • Class of the eggs (e.g. “Class A”).
    • Weight category (e.g. “Large”).
    • Best-before date (maximum 28 days from laying).
    • Storage advice: “Keep refrigerated after purchase.”
    • Farming method description (e.g., “Free-range eggs”).
    • Packing centre identification code.
Source www.egginfo.co.uk

Figure 2. British Lion stamped egg. Source: www.egginfo.co.uk

Egg grading and labelling equipment

Equipment is available to help egg producers with grading and stamping, both manual and automated systems are available.

Source: www.reidsequipment.co.uk

Figure 3. Egg grading machine. Source: www.reidsequipment.co.uk

www.reidsequipment.co.uk

Figure 4. Egg printing machine. Source: www.reidsequipment.co.uk

Hygiene and storage

Class A eggs are more valuable than Class B eggs and poor hygiene and/or storage can cause an egg to deteriorate from class A to class B.

  • Hygiene: Producers must ensure high levels of cleanliness in all production stages, including hen housing, egg handling facilities and transportation.
  • Grading Facilities: Eggs must be graded and packed in approved packing centres that comply with food safety regulations.
  • Storage Conditions: Eggs must be kept dry, clean, and at a consistent temperature to prevent quality deterioration.

Records

Egg producers must keep records of the following:

  1. The date of placing, age at placing and number of laying hens.
  2. The date of culling and the number of hens culled.
  3. Daily egg production.
  4. Number or weight of eggs delivered per day.
  5. Number and weight of eggs sold from the farm-gate.
  6. Names and addresses of purchasers and the establishment number.

Exemption from egg grading

Producers with fewer than 50 laying hens are exempt from egg grading and marking requirements if:

  • Eggs are sold directly to consumers (e.g. at farm gates, door-to-door, or local markets).
  • Packaging or signs clearly state, “These eggs are ungraded and sold directly from the producer.”

James Orr, SAC Consulting

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