Onsen Tamago literally means “hot spring eggs“ in Japanese. It refers to eggs that are slowly poached in the shell in hot spring water to create silky egg whites and custard-like yolks. Here‘s how you can make this delicious egg recipe at home.
Prep Time10 minutesmins
Cook Time20 minutesmins
Total Time30 minutesmins
Course: Side Dish
Cuisine: Japanese
Keyword: egg
Servings: 4onsen tamago
Calories: 83kcal
Author: Namiko Chen
Ingredients
4¼cupswater(1 L)
4large eggs (50 g each w/o shell)(refrigerated)
¾cuptap water(200 ml; colder than room temperature)
Before You Start: You will need a small heavy-bottomed saucepan (I use a 2-QT saucepan) in which you can completely submerge the eggs in the water. Please use exactly 4 refrigerated large eggs for this recipe to achieve the correct water temperature for poaching. Now, gather all the ingredients.
To Poach the Eggs
To the saucepan, add 4¼ cups water(1 L). Cover with a tight-fitting lid and bring it to a boil.
Once boiling, remove the pot from the heat. Remove 4 large eggs (50 g each w/o shell) from the refrigerator.
To the pot of just-boiled water, add ¾ cup tap water (200 ml) that‘s colder than room temperature. Then, gently submerge the cold eggs, one at a time, in the hot water using a fine-mesh skimmer.
Immediately cover and set the timer for 17–20 minutes (or up to 25 minutes). If you want to cook the yolk more, increase the cooking time in the future. Note: The eggs should be cooked in hot water at 154–158°F (68–70°C).
To Make the Sauce
Meanwhile, make the sauce. Combine ¼ cup dashi (Japanese soup stock), ½ Tbsp mirin, 1½ Tbsp soy sauce, and 2 Tbsp katsuobushi (dried bonito flakes) in a small saucepan and bring it to a boil.
Once boiling, turn off the heat.
Strain through a sieve and set the sauce aside.
To Finish the Onsen Tamago
Once 17–20 minutes have passed, gently take the eggs out of the water, one at a time. Set them aside for 5 minutes.
Meanwhile, cut the green onion/scallion into thin slices and set aside.
To Serve
Enjoy the Onsen Tamago either warm or at room temperature. Crack the egg into a small bowl, pour the dashi-based sauce into the bowl, and garnish with the sliced green onion as a part of a Japanese breakfast. Try the egg on top of steamed rice with a splash of soy sauce. It‘s also delicious over Gyudon, Chicken Curry Rice, Soba Noodle Soup, and Cold Tanuki Udon.
Add it to a rice bowl: It‘s a silky and rich topping for Gyudon (simmered beef bowl) and Yakiniku Don (grilled beef bowl). It also works beautifully in a poached-egg version of Tamago Kake Gohan.
Top a main dish: Add one to your Hambagu(Japanese hamburger steak), Nikomi Hambagu (stewed hamburger steak), Loco Moco, and spaghetti carbonara (my favorite). It also works well on Avocado Toast.
You can keep the uncracked Onsen Tamago for 1–2 days in the refrigerator. To reheat, remove it from the refrigerator and bring it to room temperature. To warm it up further, place it in a bowl of 160ºF (70ºC) water for 10 minutes. Do not reheat higher than that; otherwise, the heat will cook the egg. Keep any leftover sauce in the refrigerator for 4–5 days.