Cold Soba Noodles (ざる蕎麦 – Zaru Soba)
Zaru Soba is a chilled noodle dish made by boiling and chilling buckwheat noodles before serving them on a Zaru or strainer. The soba noodles are then dipped in a savory dashi-based broth as you lift each bite of noodles to your mouth. It’s a wonderfully refreshing meal that requires minimal cooking, and it can be customized with a wide variety of condiments that can be added to the sauce or used to top the noodles with.
Why This Recipe Works?
- The key to a delicious dipping sauce is to start with high-quality dashi stock.
- To achieve a great texture for the cold soba noodles, they are chilled using a two-step process. First, the starch is rinsed off, and they are brought to room temperature. Then they are chilled in ice water to make the soba cold.
- Saving the boiling liquid from the soba allows you to turn the remaining dipping sauce into a comforting soup to finish your meal.
Ingredients for Zaru Soba Dipping Sauce (soba tsuyu)
- Dashi – Dashi literally means “broth” in Japanese, and it forms the basis for this sauce (as well as many Japanese dishes). There are many ways to make dashi, as well as regional variations. The most common one is made with konbu (kelp) and katsuobushi (smoked, dried, and fermented skipjack tuna shavings). I have a recipe for making dashi from scratch, or you can use a high-quality dashi pack like the one offered in my Japanese ingredient box. If you want to make a vegan-friendly dipping sauce, check the FAQs below for details on making plant-based dashi.
- Soy Sauce – Soy sauce is the main seasoning for soba dipping sauce. Different types of soy sauce are used depending on the region of Japan, but here in Tokyo, the standard dark soy sauce like Kikkoman is what’s used. This is another area you can level up your sauce by using a more premium product. My favorite one is made by a brand called Marunaka, and they take 3 years to brew a batch of their soy sauce using traditional methods and tools that you only really see in museums these days. I include a small bottle of their soy sauce in my Japanese ingredient box.
- Sake – Sake adds both flavor and the taste of umami to the soba dipping sauce. The alcohol gets boiled off during cooking, so you don’t need to worry about that. Because the other ingredients in the tsuyu have such a high amino acid content, the sake is not required; however, the flavor and extra umami the sake brings makes it worth adding if you have it.
- Sugar – Sugar helps to balance out the saltiness of the soy sauce. Different regions of Japan use different amounts of sugar in their tsuyu. Personally, I like to have just enough to take the sharp edge off the soy sauce without being obviously sweet, so I don’t add very much, but you can adjust this to suit your preferences.
The word Soba (蕎麦) literally means “buckwheat” in Japanese, and it’s also the name by which noodles made from buckwheat are known. It’s a little confusing, though, because historically, any thin noodle was known as “soba.” This is why you hear names such as yakisoba, chuuka soba, and sōki soba, even though these are made with wheat-based noodles.
Buckwheat / Wheat Flour Ratio
Buckwheat does not contain gluten, so turning it into a dough that you can roll out and cut into noodles is challenging. This is why most modern soba is made with a mixture of wheat flour and buckwheat flour, which is a style known as Nihachi Soba (二八蕎麦). The name literally means “two-eight soba” because it was originally made with a ratio of two parts wheat flour to eight parts buckwheat flour. If you want a noodle that is made from 100% buckwheat, look for Jūwari Soba (十割蕎麦), which literally means “100% soba”.
Soba can also come in flavored varieties with ingredients such as green tea, mugwort, or seaweed added to the dough, infusing the noodles with both color and flavor.
Fresh vs. Dry Soba
Soba comes either fresh or dried. Like pasta, the fresh variety is usually better, but dried soba is still delicious if you cannot find it fresh. The boiling times for soba depend on its composition and thickness, so be sure to read the instructions on the packaging to determine the boiling time. If the instructions aren’t translated, look for the character “分”; this means “minute,” and it’s usually preceded by a number which is the boiling time. Some packages will have two sets of boiling instructions, one for making cold soba and one for making hot soba. The times will differ slightly because you want to slightly under boil the soba for hot preparations, so they don’t get soggy in the soup, while they need to be fully cooked when they’re being served chilled.
Condiments for Zaru Soba
The condiments you serve with Zaru Soba are where you can get creative, and there are many options here.
- Nori – Good quality nori has a green briny flavor and loads of umami. It’s typically cut into thin strips with scissors for serving with soba, but you can also tear it into small pieces with your hands.
- Scallions – In Japan, we have several varieties of scallions, and a very thin cultivar known as bannou negi is the one most commonly used as a condiment for soba. If you can’t find thin scallions near you, you could substitute chives. Another option is to mince up a larger scallion.
- Wasabi – Wasabi adds a nice kick to the dipping sauce if you like a little heat. Wasabi is best freshly grated, but if you can’t find it, the type out of a tube is fine as well (many of these are made from the stems and leaves of wasabi, but check the ingredient label). I don’t recommend using the powdered variety, usually made from horseradish and mustard, with coloring agents to make it look like real wasabi.
- Daikon Oroshi – Grated daikon is a common condiment to add to the dipping sauce as the particles of daikon absorb the sauce and cling to the noodles. When grating daikon, I like to use the top half (leaf-end) because it tends to be sweeter and less spicy. The bottom half (root-end) works better for cooked dishes.
- Others – Aromatic ingredients, such as ginger, myoga, yuzu zest, shiso, and sesame seeds are all possibilities. You can also add ingredients to change the texture, like raw quail egg, chopped okra, or grated yamaimo. Some people like to turn it into a salad by topping it with veggies like tomatoes, cucumber, or spinach.
How to Make Cold Soba
The first thing you want to do is to make the tsuyu by adding the dashi, soy sauce, sake, and sugar to a saucepan and bringing it to a boil. You want to boil this for about a minute or until it no longer smells like alcohol. Set the dipping sauce aside to cool. You can also put the saucepan in a bowl of ice water to chill it rapidly.
While you wait for the broth to cool, prepare all of the condiments you plan to serve with your Zaru Soba.
Bring a large pot of water to a full boil. Soba noodles already contain salt, so you do not need to salt the water. Add the noodles and stir them for a minute so that they don’t stick together. Boil the noodles for the time specified on the packaging.
When the noodles are done, use tongs or chopsticks to transfer them to a strainer. Keep the boiling water for later.
Rinse the noodles under cold running water to bring them down to room temperature, and once they’ve cooled a bit, use your hand to agitate the noodles to remove any excess starch on the surface of the soba.
Prepare a bowl of ice water and add the noodles to chill them.
Plate the noodles directly from the water bath by scooping small handfuls of soba and placing them in mounds on a zaru. If you don’t have a zaru, you can use a shallow basket or anything that will allow the excess water to drain off.
The noodles will start to stick together after a few minutes, so serve them immediately with the dipping sauce and condiments.
When you’re done eating the cold soba, you can reheat the boiling liquid and add it to any remaining dipping sauce you have to make a soothing soup to finish off the meal.
Other Cold Noodle Recipes
A zaru (笊) is a strainer that was traditionally made from woven bamboo. Since cold soba is usually served on a zaru, this is where it gets its name.
Zaru Soba is a four-syllable name that is pronounced as follows:
za like zombie
ru like the “ru” sound does not exist in the English language and the best way to make it is to say the word “ruse” with the tip of your tongue at the front of your mouth.
so like sore
ba like barb
Zaru Soba is eaten by picking up a few strands of soba noodles using chopsticks and then dipping them into a dashi-based dipping sauce. You can adjust the saltiness of the bite of noodles by how far you dip the noodles into the cup of sauce, so I usually start off by only partially dipping them in the sauce. Then as the dipping sauce gets a little watered down, you can submerge them more fully in the tsuyu. Various condiments, such as scallions and wasabi, can be added to the dipping sauce to change the flavor and texture as you eat the noodles, which helps keep the meal interesting.
As with any Japanese-style noodle, it is perfectly acceptable to slurp soba noodles. This not only helps you get them into your mouth, but it also aerosolizes some of the aromatic compounds, allowing you to enjoy the fragrance of the noodles and dipping sauce in the same way you would enjoy fine wine.
Sobayu (蕎麦湯) literally means “soba boiling liquid,” and it’s the hot water the soba noodles were boiled in. It is typically served in a teapot at the end of a soba meal, and it can be drunk as is like tea, or it can be added to the remaining dipping sauce to make a comforting soup to finish off your meal.
Soba noodles are typically plant-based, however, the dipping sauce includes dashi stock, and if the dashi has fish, it would not be plant-based. That being said, it is very easy to make vegan-friendly dashi stock by soaking dried shiitake mushrooms and konbu in water overnight.
For dipping sauce
- 1 cup
scallion (finely chopped)
daikon (grated and drained)
nori (cut into thin strips with scissors)
To make the dipping sauce, add the dashi, soy sauce, sake and sugar to a saucepan, and bring the mixture to a boil. Continue boiling for 1 minute to vaporize the alcohol in the sake and soy sauce. Set this aside to cool.
To boil the soba noodles, bring a large pot of water to a rolling boil. Add the soba noodles and stir for about a minute to ensure the noodles don’t stick together. Continue boiling the noodles for the amount of time specified on the package.
Transfer the noodles to a strainer using chopsticks or tongs (leaving the boiling liquid in the pot).
Wash the soba under cold running water to cool it to room temperature while removing any excess starch on the noodles’ surface.
Transfer the soba to a bowl of ice water and let the noodles chill for a moment.
Serve the noodles by scooping small amounts of soba out of the ice water and bundling them up into small mounds on a zaru or large flat basket.
Serve immediately with the dipping sauce and condiments.
Once you've finished eating the cold soba, reheat the boiling liquid and serve it in a teapot to add to the remaining dipping sauce to make a broth.