Bathed in an icy shiro dashi soup broth, this Cold Somen Noodles with Sudachi Lime is a refreshing treat on a hot summer day. The light color of this savory and tart broth brings out the vibrant green and yellow hues of the citrus slices for a cooling and beautiful presentation.
Gather all the ingredients. If using homemade shiro dashi instead of store bought, you will need to prepare ice cubes instead of the iced water shown in the image. In addition, you can prepare several more ice cubes to add to the serving bowls if you prefer your noodles extra chilled (optional).
Thinly slice all but 1 of the 5 sudachi (or 2–3 limes) and set aside for garnish. Cut the 1 remaining sudachi in half widthwise and reserve for juicing.
To Prepare the Ice-Cold Soup Broth (1⅔ cups, 400 ml)
If you‘re using homemade shiro dashi, combine 1¼ cups (300 ml) homemade shiro dashi and 1 cup (3.5 oz, 100 g) ice cubes (NOT iced water). Tip: My homemade shiro dashi is not as concentrated as the store-bought type.
If using store-bought shiro dashi, combine ⅓ cup (80 ml) concentrated shiro dashi and 1⅓ cups iced water (320 ml), including several ice cubes. Tip: Each brand of shiro dashi has different saltiness, so please adjust to your liking. Once you have added either ice cubes or iced water to your shiro dashi base, squeeze the sudachi (or lime) halves and add the juice to your prepared shiro dashi broth. Mix it all together.
To Cook the Somen Noodles
Bring a large pot of water to a boil. (You do not need to add salt to the water.) Meanwhile, remove all the wrappings from 4 bundles dried somen noodles, as all the noodles should go into the boiling water at the same time. Tip: Somen noodles cook very fast, so it‘s important to work quickly. When the water is boiling, add the somen all at once, spreading the noodles around the pot in a circular motion to separate each strand (I use a motion similar to opening a Japanese folding fan).
Cook in the boiling water, stirring occasionally with chopsticks, for 1 to 1½ minutes or according to the package instructions. If it looks like the water may boil over, add a small amount of cold water to the pot. When the noodles are done, drain them in a colander. Tip: I slightly undercook my noodles to keep their springy texture.
Rinse the somen under cold running water. Once the noodles are cool enough to handle, rinse them with your hands as if you are washing your clothes. Knead and massage the noodles to get rid of the excess oil.
To Assemble and Serve
Serve the cold somen noodles in individual bowls and add several ice cubes (optional) to the bowls. Add enough soup broth to the bowls to reach halfway up the noodles. Depending on the size and shape of your bowls, you may need to make more broth.
Garnish on top with the thinly sliced sudachi and serve immediately.
To Store
You can keep the leftovers in an airtight container and store in the refrigerator for up to 2 days. If the noodles stick to each other under refrigeration, run them under cold water to loosen them up before serving. Ideally, you should boil the noodles right before serving so they won't lose their perfectly springy texture.