📝 About This Recipe
Tentsuyu is the soul of Japanese tempura, a delicate balance of savory, sweet, and smoky flavors that elevates light-as-air fried delicacies. This traditional recipe relies on the 'golden ratio' of dashi, soy sauce, and mirin to create a thin, fragrant broth that cuts through richness without overpowering the natural flavors of the ingredients. Mastering this sauce is the secret to bringing a true Tokyo-style tempura house experience into your own kitchen.
🥗 Ingredients
The Dashi Base
- 2 cups Water (filtered is best)
- 1 piece Kombu (Dried Kelp) (approx. 4x4 inches, wiped gently with a damp cloth)
- 1 cup Katsuobushi (Bonito Flakes) (tightly packed)
The Seasoning Liquid
- 1/2 cup Soy Sauce (Japanese dark soy sauce (Koikuchi))
- 1/2 cup Mirin (Hon-mirin (true mirin) preferred over mirin-fu)
- 1 tablespoon Granulated Sugar (adjust to taste for sweetness)
- 2 tablespoons Sake (dry culinary sake)
Traditional Accompaniments
- 4 inch piece Daikon Radish (peeled and finely grated)
- 1 inch piece Fresh Ginger (peeled and finely grated)
- 2 stalks Green Onions (sliced into very thin rounds)
👨🍳 Instructions
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1
Begin by making the dashi. Place the water and the wiped kombu piece in a medium saucepan. Let it soak for at least 30 minutes to extract the initial glutamates.
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2
Place the saucepan over medium heat. Just before the water reaches a rolling boil (look for small bubbles forming at the edges), remove the kombu with tongs and discard. This prevents the sauce from becoming slimy or bitter.
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3
Bring the liquid to a full boil, then immediately add the katsuobushi (bonito flakes). Let it boil for only 30 seconds to infuse the smoky aroma.
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4
Turn off the heat and let the bonito flakes sink to the bottom of the pan, which should take about 2-3 minutes.
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5
Strain the dashi through a fine-mesh sieve lined with a paper towel or cheesecloth into a clean bowl. Do not squeeze the flakes, as this can make the dashi cloudy.
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6
Rinse the saucepan and pour the strained dashi back in. Add the soy sauce, mirin, sake, and sugar.
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7
Bring the mixture to a gentle simmer over medium-low heat, stirring occasionally until the sugar is completely dissolved.
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8
Once simmering, let it cook for 2-3 minutes to allow the alcohol from the mirin and sake to evaporate, leaving only the sweetness and depth.
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9
Remove from heat. For tempura, Tentsuyu is traditionally served warm, but it can also be served at room temperature.
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10
While the sauce cools slightly, grate the daikon radish using a fine grater. Lightly squeeze out the excess moisture so you are left with a fluffy mound.
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11
Grate the ginger and finely slice the green onions. Set these aside in small individual bowls.
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12
To serve, pour the warm sauce into individual small dipping bowls. Instruct guests to add the grated daikon, ginger, and onions into their sauce to their own liking.
💡 Chef's Tips
Always use Japanese soy sauce; Chinese or Thai varieties are often too salty or have a different flavor profile for this delicate sauce. If you are in a rush, you can use 1 teaspoon of dashi granules dissolved in 2 cups of water, though fresh dashi is significantly superior. Don't skip the daikon! The enzymes in the radish actually help digest the oil from the fried tempura. For a deeper flavor, you can make the sauce a day in advance and store it in the fridge; just reheat gently before serving. Adjust the sugar slightly depending on how sweet your mirin is; the sauce should be savory first with a gentle sweet finish.
🍽️ Serving Suggestions
Serve alongside a platter of crispy Shrimp and Vegetable Tempura. Use it as a light dipping sauce for cold Soba or Udon noodles. Pair with a chilled glass of dry Junmai Sake or a crisp Japanese lager. Drizzle over a 'Ten-don' (Tempura Rice Bowl) for a quick and satisfying meal. Serve with a side of lightly pickled cucumbers (Sunomono) to cleanse the palate.