Prep time: 15 minutes
Total time: 2 hours
for the bonito and kombu dashi:
5 cups|1.2 liters filtered water
1 piece kombu, about 3 x 3 inches (7.5 x 7.5 cm)
3 to 4 cups|20 to 30 grams bonito flakes
for the shoyu tare:
1/3 cup plus 1 tablespoon|80 ml mirin (hon mirin, not mirin-type)
3 tablespoons cane sugar
2 cups|480 ml soy sauce or usukuchi shoyu (light-colored soy sauce)
for the dipping sauce:
1 cup|236 ml shoyu tare
3 cups|700 ml bonito and kombu dashi or other dashi of your choice
for the noodles:
3 1/3 cups|400 grams soba-grade buckwheat flour (sobakoh)
¾ cup|100 grams all-purpose flour or whole wheat flour (preferably Sonora wheat or Pasayten
1¼ cup|260 ml filtered water
1 cup|128 grams tapioca starch
2 quarts|2 liters ice water
1 cup toasted finely ground walnuts mixed with 1 tablespoon|18 grams cane sugar
grated daikon radish
1. Make the dashi: Combine the water and kombu in a medium saucepan. Heat over low heat until bubbles begin to form around the kombu, 5 to 10 minutes. Remove the piece of kombu before the water comes to a boil. Bring the water to a boil, turn off the heat. Add the bonito flakes. Let stand for 2 minutes, without stirring, to steep the bonito flakes.
2. To strain the dashi, pour the liquid through a fine-mesh sieve or a sieve lined with cheesecloth or a paper towel. Do not press the bonito flakes while straining, as it will cloud the dashi. Use immediately, or cool completely and refrigerate for up to 4 or 5 days or freeze up to 1 month.
3. Make the shoyu tare: Combine the mirin and sugar in a small saucepan, place over medium heat, and stir to dissolve the sugar completely. Lower the heat, add the soy sauce, and heat until it starts to simmer, about 3 minutes. Remove from heat and set aside to cool to room temperature. Store in a nonreactive container in a cool, dry place or in the refrigerator, where it will keep for up to 3 months.
4. Make the dipping sauce: Bring the shoyu tare and dashi to boil over medium heat. Lower heat and cook for 2 minutes. Turn off heat. Bring to room temperature. Serve with the noodles. This will keep in the refrigerator for 4 to 5 days.
5. Make the noodles: Line the bottom of a large bowl with a damp paper towel so the bowl doesn’t move. Sift the buckwheat and all-purpose flours into a large bowl. Set aside 2 tablespoons of the water and put the rest in the bowl. Work the water into the flour in a swirling pattern. Quickly toss together the flour and water, using your fingertips, until well combined. If you have any flour on your fingers, scrape it off and add it back into the dough. Continue to work the dough until it forms a crumbly mass.
6. Working quickly and using the palms of your hands in circular motion (Wax on! Wax off!), knead the dough until it becomes smooth, shiny, and with no visible cracks. If the dough feels dry, add a tablespoon of water, and continue kneading until the crumbly mass becomes little dough balls. Gather the small balls and shape them into one large ball. Knead the ball until it is semi firm and smooth (it should feel like your earlobe), not sticky. Press the ball into a disk about 1 inch (2.5 cm) thick. This will take about 5 minutes. If the dough still feels dry, add an additional tablespoon of water but don’t be tempted to add any more. You don’t want a wet dough.
7. Sprinkle the cutting board and the dough with a pinch of starch. Using a rolling pin, roll the disk into a rectangle shape about 18 inches (45 cm) square and ⅛ inch (3 mm) thick. Feel the entire surface of the dough to check if there are any thick areas. Do not flip the dough while you are rolling it out. You want the dough to have an even thickness.
8. Generously sprinkle the tapioca starch over half of the dough and fold the other half on top of it (the dusting starch will keep the dough from sticking to itself). Generously dust another half of the dough, perpendicular to the rectangle you just folded, with tapioca starch and fold again. You will be shaking off the starch after the noodles are cut, so don’t worry about overdusting.
9. You now have a “stack” of dough that is 4 layers deep. Starting along the short, folded side of the dough, use a ruler and knife (or cutting guide and soba knife) to slice it into thin noodles that are even in size, about ⅛ inch (3 mm) thick (the thick-ness will vary from person to person). The idea is to handle the noodles gently (being careful not to squash them) and shake off the dusting starch by tapping the noodles on both ends. Transfer the noodles to a baking sheet, laying them flat. Do not bundle the noodles like you would with pasta or udon, or they will break. When the pan is full of noodles, cover it with a dish towel or plastic wrap and keep refrigerated until you are ready to cook the noodles. They are best made and eaten on the same day, but they will keep for up to 2 days in the refrigerator
10. To cook the noodles, bring a stockpot of unsalted water to a rolling boil over high heat. Gently drop the noodles into the boiling water, making sure the water stays vigorously boiling so the noodles don’t stick together. Do not use ramen baskets. Cook only 2 servings at a time, so the noodles can swim in the pot, but do not stir. Cook the noodles until al dente, about 90 seconds (if they are thin like spaghetti) to 3 minutes (if they are thick like linguini). The timing will vary depending on the thickness of the noodles.
11. Scoop the noodles with a large sieve in one scoop. Transfer the noodles to a strainer that is set in the bowl of water to stop the cooking. Remove any surface starch by giving the noodles a vigorous rinse under cold running water. Drain and then rinse the noodles once more. Drain thoroughly by hitting the side and bottom of the strainer but don’t toss the noodles. Serve immediately with dipping sauce. The noodles are best eaten fresh. Cooked soba noodles do not hold up in the refrigerator very well. Serve the noodles in a zaru (Japanese-style bamboo basket), if you have one, or on a large platter with individual serving bowls of dipping sauce and ground walnuts.
12. Invite diners to mix the ground walnuts into the dipping sauce, dip in the noodles, and slurp. You may also serve a more classic dipping sauce along with the walnut dipping sauce. Simply serve the noodles with grated daikon radish, sliced scallions, and grated wasabi.
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