How long to boil a jammy egg
Jammy · Large · Fridge
Get the ice bath ready. Yolks keep setting after the pan comes off.
Duck, quail, altitude and more
Jammy egg timing worked out for your egg size and kitchen, with a timer. The thick, custardy yolk used for ramen eggs.
The short answer
A large, fridge-cold egg lowered into boiling water at sea level needs 7 min 30 sec for jammy, thick and sticky. Bright, custardy yolk that holds its shape but still smears. The ramen egg.
| Egg size | From the fridge | Room temperature | Cold water start |
|---|---|---|---|
| Small | 6 min 15 sec | 4 min 45 sec | 3 min 45 sec |
| Medium | 6 min 45 sec | 5 min 15 sec | 4 min 15 sec |
| Large | 7 min 30 sec | 5 min 45 sec | 4 min 30 sec |
| Extra large | 8 min | 6 min 15 sec | 5 min |
| Jumbo | 8 min 30 sec | 6 min 45 sec | 5 min 15 sec |
Jammy, thick and sticky at sea level. Use the calculator above to adjust for altitude.
What a jammy egg is for
Ramen, almost always. This is the ajitsuke tamago consistency: a yolk that holds its shape when the egg is halved but smears across the tongue rather than crumbling. It is also the right egg for a grain bowl or a salad where you want the yolk to act as part of the dressing. Marinate it overnight in soy, mirin and water if you want the real thing.
How to tell it worked
Halve it with a wet knife. The yolk should be a deep orange gel, glossy, holding a clean cut edge without running. If a drop escapes the cut it is closer to soft. If the centre looks matte and pale rather than glossy, it has gone to medium.
The usual mistake
Treating thirty seconds as a rounding error. Jammy sits in a roughly ninety second band between runny and set, which is why this doneness rewards a timer more than any other. Egg size matters more here too: a jumbo egg at the time for a large one comes out noticeably softer.
Making ajitsuke tamago, the marinated ramen egg
The marinade is equal parts soy sauce, mirin and water. That is the whole recipe. Some people add a spoon of sugar or a slice of ginger, and it is worth trying once you know what the plain version tastes like.
Peel the eggs while they are properly cold, then sit them in the liquid in a container just big enough to hold them. They float, so lay a folded piece of kitchen paper over the top and the liquid wicks up into it, which keeps the exposed side covered without needing twice the marinade.
Four hours gets you flavour on the surface. Overnight gets you the deep brown ring and a seasoned white, which is what you are after. Past about two days the white turns rubbery and over salted, so take them out and eat them.
The marinade is reusable two or three times if you keep it in the fridge, and it gets better each round as it picks up egg. It is also excellent poured over rice.
Other boiling times
Egg guides
Common questions
Should the eggs go into cold water or boiling water?
Boiling water gives you far more control, because the clock starts at a known temperature. Cold-water starts work too, but the time depends on how fast your hob heats the pan, so treat the cold-start numbers as a guide and check one egg. Pick "cold-water start" above and the times adjust for you.
Why does my timing keep coming out wrong?
Usually egg size or starting temperature. A jumbo egg needs about two minutes longer than a small one for the same result, and a fridge-cold egg needs roughly a minute and a half longer than one left on the counter. Altitude matters too: above about 1,500 m the water boils below 100 °C, so everything takes longer.
Is a jammy yolk safe to eat?
For most people, yes, particularly with pasteurised or high-welfare eggs. Food safety agencies advise that people who are pregnant, very young, elderly or immunocompromised cook eggs until both white and yolk are firm. If that applies, use the hard-boiled time instead.
How do I stop the cooking at the right moment?
Move the eggs straight into iced water. The shell holds a lot of heat and the yolk keeps setting for a minute or two after you drain the pan, which is what turns a jammy yolk chalky. An ice bath also contracts the egg away from the shell and makes peeling far easier.
What causes the grey-green ring around the yolk?
Overcooking. Iron in the yolk reacts with sulphur in the white and forms iron sulphide. It is harmless but it tastes flat and chalky. Use the time above rather than a generic one and cool the eggs immediately and you will not see it.
Egg times come from the thermal-diffusion equation for a spherical egg published by Charles D. H. Williams (University of Exeter), calibrated so a large fridge-cold egg at sea level matches the times cooks actually use. Size, starting temperature and altitude then follow from the physics. Treat the result as a very good starting point, not a guarantee, because pans, hobs and eggs all vary.