Onsen Tamago (Hot Spring Eggs) | Easy Japanese Recipes at JustOneCookbook.com

Onsen Tamago

Course: Appetizer, Breakfast, Side Dish
Cuisine: Japanese
Keyword: egg, hot spring egg
Prep Time: 5 minutes
Cook Time: 25 minutes
Total Time: 30 minutes
Servings: 4 Onsen Tamago
Author: Nami
Onsen Tamago 温泉卵 literally means ‘hot spring eggs’ in Japanese. It refers to eggs that were originally prepared in hot spring water to create silky egg whites and custard-like yolk. Today I’m going to show you how you can make this delicious egg recipe at home.


  • 1000 ml water (about 4 cups)
  • 200 ml tap water (little bit less than 1 cup) (needs to be colder than room temp)
  • 4 large eggs (refrigerated)



  1. Gather all the ingredients.

    Onsen Tamago Ingredients
  2. Add 1000 ml water in a heavy bottom saucepan, cover and bring it to a boil.
    Onsen Tamago 1
  3. Once boiling, remove the pot from the heat. Take the eggs out from the refrigerator. Add 200 ml cold tap water and gently submerge the cold eggs in the hot water. Immediately cover and set the timer for 17 minutes.
    Onsen Tamago 2
  4. If you like to enjoy onsen tamgo with the sauce, combine the dashi, mirin, and soy sauce in a small saucepan and bring it to a boil. Add katsuobushi and turn off the heat, let katsuobushi sink at the bottom of the pan. After 30 seconds or so, strain through the strainer and set the sauce aside. You can keep the sauce in refrigerator for 4-5 days.
    Onsen Tamago 3
  5. Cut scallion into thinly slices and set aside.
    Onsen Tamago 4
  6. Once 17 minutes have passed, take the eggs out gently and set aside for 5 minutes.
    Onsen Tamago 5
  7. You can enjoy onsen tamago either cold or warm. Crack the egg and pour the sauce over, garnish with chopped scallion. 
    Onsen Tamago 6

To Store

  1. You can keep the onsen tamago for 1-2 days in the refrigerator. To reheat, take out the onsen tamago from the fridge to room temperature. Place it in 160 ºF(70 ºC) water for 10 minutes to warm up. Do not reheat higher than that otherwise the egg will be cooked.

Recipe Notes

Equipment you will need:



Recipe by Namiko Chen of Just One Cookbook. All images and content on this site are copyright protected. Please do not use my images without my permission. If you’d like to share this recipe on your site, please re-write the recipe in your own words and link to this post as the original source. Thank you.