Ajitsuke Tamago (Marinated Soft-Boiled Eggs)

Fact-checked on paper only. This recipe has not been cooked or tested yet.

Why this works

Seven minutes in boiling water gives a jammy yolk with large eggs, and an ice bath stops the cooking [Just One Cookbook]. The marinade is made first and cooled so it does not cook the egg. A jammy yolk is not cooked firm, so this topping carries real food safety limits, listed below.

Yield: 6 eggs Times: prep PT10M, cook PT7M, total PT8H17M (ISO 8601)

Equipment

• Medium saucepan
• Slotted spoon
• Bowl of ice water
• Zip-top bag or snug lidded container

Ingredients

• 6 large eggs, cold from the refrigerator
• 120 ml (1/2 cup) soy sauce
• 60 ml (1/4 cup) mirin
• 60 ml (1/4 cup) sake
• 60 ml (1/4 cup) water
• 15 g (1 Tbsp) sugar

Steps

1. Boil the soy sauce, mirin, sake, water and sugar together for 1 minute. Cool it completely.
2. Bring a pot of water to a rolling boil and lower the cold eggs in gently with a slotted spoon.
3. Boil exactly 7 minutes for jammy yolks.
4. Move the eggs to an ice bath for at least 10 minutes.
5. Crack the shells all over and peel under cold running water, starting at the wide end.
6. Put the eggs and the cooled marinade in a bag or snug container so they are covered. Refrigerate 8 to 24 hours, turning once or twice.

What to watch for

• Older eggs often peel more cleanly than very fresh ones.
• Do not go past 24 hours in the marinade. Just One Cookbook warns the eggs get too salty after 12 to 24 hours.
• Keep them cold the whole time.

Storage

• Keep refrigerated at 40 F (4 C) or below. Soft-boiled marinated eggs keep 3 to 4 days [Just One Cookbook]. We say 3 days for runny yolks and 4 days at most for jammy ones. Do not freeze.
• Chill within 2 hours of cooking, or 1 hour above 90 F [USDA FSIS, Keep Food Safe].
• Food safety: the FDA says to cook eggs until the yolk and white are firm and warns that young children, older adults, pregnant women and people with weakened immune systems are at higher risk from undercooked eggs [FDA]. Serve these eggs only to people who are not in those groups, or cook them hard.

Allergens: Egg, soy, wheat (soy sauce).

Pairs with

Any bowl. Pairs well with shoyu tare and tonkotsu.

Sources

1. Just One Cookbook, ramen egg (7 minute boil, marinate 8 to 24 hours, 3 to 4 days soft-boiled): https://www.justonecookbook.com/ramen-egg/
2. FDA, What You Need to Know About Egg Safety (cook until yolk and white are firm; at-risk groups): https://www.fda.gov/food/buy-store-serve-safe-food/what-you-need-know-about-egg-safety
3. USDA FSIS, Keep Food Safe (2 hour / 1 hour chilling rule): https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/steps-keep-food-safe

Citation links

• https://www.justonecookbook.com/ramen-egg/
• https://www.fda.gov/food/buy-store-serve-safe-food/what-you-need-know-about-egg-safety
• https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/steps-keep-food-safe