An easy step-by-step guide to making molten-centred ramen eggs

Also known as nitamago or lava egg, the egg white is completely cooked, while the egg yolk remains molten. It's marinated overnight in a soya sauce mixture, and mostly eaten with ramen.

Recipe by Hideki Miyazaki, sub-group leader of the Asia-Oceania research and development team at Chikaranomoto Global Holdings, the founding company of Japanese restaurant Ippudo


For the marinade:
70ml Japanese soya sauce
70ml mirin
200ml water
1 piece kombu (kelp), cut into 5cm squares
5 eggs, at room temperature


1. Use only room-temperature eggs, as cold eggs may crack in boiling water.

2. If the marinade doesn't cover the entire egg, soak a paper towel with the marinade and place it on top of the eggs.


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1. Combine the marinade ingredients in a pot, and bring to the boil. Remove the kombu and simmer for 3min. Remove from heat, and cool to room temperature.

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2. Bring a pot of water to the boil. Submerge the eggs and boil over medium heat for 7min. Stir the eggs in the same direction every 2min to help the yolks stay in the centre.

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3. Remove the eggs, and place them in a pot of ice water for 5min. While the eggs are in the water, gently use a spoon to tap on the egg shells to make them easier to peel.

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4. Peel the eggs and place them in the marinade, making sure they are completely covered. Refrigerate overnight. The eggs can keep for up to 3 days. Halve each egg before serving.

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How to tell if your egg has gone bad

  • Place your egg in a basin of water and if it floats, it is not fresh and should be binned.
  • If the egg lies on its side at the bottom, it is very fresh.
  • If it stays upright on the bottom, it is still fine to eat, but should be eaten very soon, or hard-boiled.
  • If it is fresh, it will not make a sound. Older eggs will make a slight rattle.
  • First, the yolk of a fresh egg should be bright yellow and nicely rounded.
  • Second, as the egg ages, the white becomes runny and the yolk becomes flatter and slightly pale.
  • If you find it difficult to peel a hard-boiled egg, do not complain. It just means that it is fresh; fresher eggs are harder to peel.
  • You should keep them refrigerated. Those kept at room temperature will go bad faster than refrigerated ones.
  • And you should store them in their carton in the main compartment and not in the fridge door, which is not cold enough. Use the eggs within three weeks.
  • Open the egg carton and make sure that the eggs are clean and the shells are not cracked.
  • You should cook an egg until the yolk and the white are firm.
  • Scrambled eggs should not be runny.
  • Eat half-boiled eggs at your own risk.
  • For recipes that call for eggs that are raw or undercooked - such as Caesar salad dressing and ice cream - use pasteurised egg products, sometimes found in supermarkets.
  • By the way, you can freeze eggs to extend their shelf life, up to a year. To freeze whole eggs, beat the yolks and the whites together. Egg whites can be frozen by themselves. (Freezing eggs in their shells does not work.)

A guide to the different types of eggs

  • These vary in size from 40g to 70g weighed in shell. Yolk colour relates to chicken feed make-up and has nopredictable bearing on flavour, neither does shell colour. Jumbo eggs often have relatively larger yolks, and sometimes double yolks, which occur randomly, often in younger hens. First-born eggs come from first-time layers, but are not nutritionally distinct from other eggs. Both yolks and whites thin out as eggs age.

  • Battery eggs, the most common kind, are from hens confined to indoor battery cages. Cage-free or barn eggs come from hens allowed some measure of freedom to roam in enclosed indoor barn spaces. Free-range eggs from hens allowed some outdoor exposure are not produced in Singapore.
  • Some producers raise hens on feed formulated to give their eggs particular nutritional profiles. According to Seng Choon Farm, natural and nutrient-rich feed ingredients are used to produce their speciality lines, such as Carrot Eggs. Nutrition aside, flavour differences among all kinds of regular or speciality chicken eggs are often only very subtle.
  • These small eggs, around 30g each, are from kampung hens, a different breed from regular layers.

  • Laid by white-feathered, black-fleshed silkie hens, also known as black chickens. Around 30g each, the eggs are mild-tasting, with smooth, rich yolks.

  • Most commonly sold are quail eggs, about 10g each, with pale but proportionately large and richyolks. Local farm stores, such as, may stock very limited supplies of eggs from other birds, such as pigeon or guinea fowl. Fresh duck eggs are not sold in Singapore, due to avian flu concerns.

  • Some supermarkets sell chilled eggs to cater to Japanese or other diners who favour raw or partly cooked eggs, and hence prize extreme freshness. For example, Seng Choon Farm packs chilled eggs for Meidi-Ya. Some gourmet supermarkets store all eggs in chillers. At home, store egg cartons on a fridge shelf. Temperatures in frequently opened fridge doors are less stable, and fluctuations may cause condensation on egg shells, which can promote bacterial or mould growth. Always observe use-by dates.
  • Producers may sanitise egg exteriors with ultraviolet light exposure before packing. Some use hot water baths to pasteurise whole in-shell eggs. Look for these in supermarket chillers. Gourmet or health food stores sometimes stock cartons of pasteurised liquid eggs or egg whites, products more often used by the food service industry than home consumers.

  • Traditionally made by curing duck eggs for a few months in an alkaline mixture of calcium oxide, tea, ash, clay, salt and rice chaff. Modern cures are often modified for faster results though the eggs are still typically sold crusted in rice chaff. Their green-grey yolks and cola-hued, firmly jellied whites have a sulphurous, even cheesey aroma and flavour. The most prized ones have branching crystalline patterns on their surface and creamy-centred yolks.

  • Immersing fresh duck eggs for several weeks in brine, sometimes spiked with spices or rice wine, turns their yolks firm and deep orange, their whites viscous and both very salty. The finished, drained eggs are smeared with ash paste for shelf storage and always cooked before consumption. Chicken eggs and quail eggs can also be salt-cured though they are less flavourful.
  • An increasingly rare sight at wet markets, these are half-formed eggs found inside the bodies of hens slaughtered for meat. Mostly yolk inside a thin membrane, ranging from pea-size to about 2cm in diameter, they taste less rich than regular eggs. Traditionally cooked in soups, curries, stews or congees by many cultures.
  • Chiefly used by the food service industry. Baking supply shops may stock powdered dried egg whites, or meringue powder, a mixture of dried egg whites, sugar and stabilisers. Both products have specific confectionery and patisserie applications.