What are the bits and spots in my egg, and are they safe?

Almost everything unexpected inside an egg is a normal feature of a biological object rather than a fault. Knowing which is which stops a lot of perfectly good eggs going in the bin, and it also sharpens the one signal that really does matter.

Step by step

1. The white cords — chalazae.Two twisted white ropes running from the yolk towards each end of the egg. They anchor the yolk in the centre. They are more prominent in fresh eggs and become less so with age, so a very visible chalaza is good news. Strain them out for a smooth custard if you like; otherwise ignore them.
2. Blood spots.A small red speck on or near the yolk, from a tiny blood vessel that ruptured on the surface of the yolk as it was released. It happens in a small percentage of eggs, has nothing to do with fertilisation, and is harmless. Lift it out with a spoon or the corner of a shell if it bothers you.
3. Meat spots.Small brown or grey-brown specks in the white, which are fragments of tissue picked up from the hen's oviduct. Also harmless, also unrelated to freshness or safety. Commercial candling removes most eggs with visible spots, which is why they are rarer in shop eggs than in farm eggs.
4. Cloudy or clear white.A cloudy, slightly milky white means the egg is very fresh — the cloudiness is dissolved carbon dioxide that has not yet escaped through the shell. A completely clear white is an older egg. Neither is a problem.
5. Thin, spreading white.Fresh whites have a thick inner layer that stands up around the yolk. As an egg ages that layer breaks down and the white spreads out flat in the pan. This is why fresh eggs poach neatly and older ones spread, and why older eggs are better for boiling and peeling.
6. Yolk colour.Anywhere from pale yellow to deep orange, and it is set entirely by what the hen ate — carotenoids from maize, marigold extract, grass or supplements. It says nothing about nutrition, welfare or freshness, despite being the single thing people judge eggs by.
7. Double yolks and no yolk at all.Double yolks come from young hens whose laying cycle has not settled and are simply a bonus. Tiny yolkless eggs, sometimes called wind eggs, come from the same unsettled cycle. Both are edible and normal.
8. The signals that do mean discard.Any sour, sulphurous or genuinely bad smell on cracking. A white or yolk with a pink, iridescent green or fluorescent cast, which indicates spoilage bacteria. Visible fuzzy mould inside the shell. A shell that is cracked, wet or slimy. Anything else on this page is fine.

Tips

• Crack eggs into a separate small bowl before adding them to anything. One bad egg found in a bowl on its own costs you an egg; found in a cake batter it costs you the batter.
• A greenish tinge to the white in a very fresh egg is riboflavin and is completely normal.
• A grey-green ring on a hard-boiled yolk is an overcooking artefact, not a defect of the egg.
• Free-range and organic hens often lay more variable eggs simply because their diet varies more. Uniformity is a processing outcome, not a quality one.
• The float test tells you about air cell size, which tracks age. It does not test for spoilage. Cracking and smelling is the test that answers the safety question.

Common mistakes

• Throwing away an egg because of a blood spot — It is a burst capillary in an unfertilised egg, present in a small share of all eggs. It is not blood from an embryo and it is not a sign of anything wrong.
• Judging egg quality by yolk colour — Colour is a feed decision that producers control deliberately to match what shoppers expect. A pale yolk from a wheat-fed hen is nutritionally equivalent to a deep orange one.
• Using the float test as a safety check — It measures how much air has diffused into the egg, which is an age proxy. An old egg that floats may be perfectly good, and a fresh egg that sinks can still be contaminated. Use your nose.

Questions people ask