If you had asked me even a couple of months ago if there was a universal rule to salads, I'd have told you that they all need a vinaigrette. A vinaigrette, I would have continued, is a sauce that, in the simplest sense, is an emulsion of a fat (usually oil) and an acid (usually vinegar or lemon juice). And I would have argued that one of the keys to any good vinaigrette, and therefore any good salad, is to perfectly balance the ratio of acid to fat, so that the salad tastes both rich and bright without being greasy or sour.
Thing is, I don't believe that anymore...at least, not entirely. In particular, I'm no longer convinced that a salad needs an acid at all. Now, before anyone starts thinking that I'm talking about replacing vinaigrettes with creamy dressings, like blue cheese or ranch, let me be clear that that's not what I mean at all. A creamy dressing works much the same way as a vinaigrette, balancing tart, acidic ingredients and rich, fatty ones (so, for the sake of this argument, I'm considering them a subset of vinaigrettes). No, I mean no acid at all.
I first had the idea to drop the acid after Japanese food expert and cookbook author Nancy Singleton Hachisu gifted me a bottle of shoyu-dashi from one of her favorite sources in Japan. It's a simple condiment that blends soy sauce (shoyu) with dashi, the Japanese stock most often made from kombu seaweed and smoked, dried bonito. The combination of the two makes a deeply savory sauce that is one of the most basic building blocks of Japanese cuisine.*
* It's often used to dress vegetables. It's the base for dipping sauces for tempura or shabu-shabu. If you order soba, they'll come served in a shoyu-dashi broth, as will udon. It's used to poach fish or to braise meats and vegetables. It's served with fried tofu in izakayas (with a cold beer, of course). It's in the marinade for carpaccio-like beef tataki and used to flavor the beef in gyudon (beef rice bowl). You get the idea: This is versatile stuff.
When I first opened the bottle Nancy gave me, I started by following a more traditional approach, spooning the shoyu-dashi directly onto some steamed winter squash. Then I moved on to drizzling it on salad greens, which is a common thing to do in Japan. But then I began to wonder why I couldn't extend even further to a vinaigrette-style construction, blending the shoyu-dashi with oil and tossing it with my salad ingredients. My first attempt was a revelation, a green watercress salad that ranked as one of the most delicious I've made, with nary a hint of acidity in it. I'm half ready to declare shoyu-dashi a more versatile condiment than mustard or ketchup.
I've been trying to think about why shoyu-dashi works so well in place of the acid part of a classic vinaigrette. One explanation I have is that an oil-dressed salad isn't unlike other dishes with a fatty component, like, say, steak. Some of the most popular condiments for steak follow the logic of a vinaigrette, providing a tart counterpoint to the rich steak; Worcestershire and chimichurri are a couple of examples. But others double down on that richness instead of trying to contrast it, like a compound butter that melts on top of the beef. So my thinking is that when it comes to salads, a tart vinaigrette is one very good and logical option, but it isn't the only one—going for deep, savory base notes instead can be very interesting.
Theories aside, what's most important is that it works, and it works well. And you don't need a bottle of fancy Japanese stuff gifted to you to do it yourself. Shoyu-dashi is incredibly easy to make at home.
The first step is to combine the kombu with cold water and bring it to just shy of a simmer, extracting its glutamic acid and mild marine flavor into the broth. Then the kombu is plucked out (you can save it for a second-run dashi, chop it up and eat it, or toss it if you're feeling lazy), and the bonito flakes are added off the heat.
The bonito is left to steep for 10 minutes, enough time to pull the fish's rich inosinic acid, along with its smoky scent, into the dashi. Once strained, the dashi is ready—it really is that quick and easy. Take note: Glutamic and inosinic acids, while chemically acids, don't taste tart. Instead, they add those satisfying, savory umami flavors.
Then you blend the dashi with soy sauce to make the shoyu-dashi. From there, it's a simple matter of making a dressing by blending the shoyu-dashi with oil and tossing it on salad ingredients.
You'll notice when you look at the recipe (linked above and below) that you have to make more dashi and shoyu-dashi than the actual recipe requires—that's just because making smaller amounts becomes impractical. You can use the extra dashi for all sorts of things, stirring in some miso for a quick miso soup or just drinking the dashi as a warming broth. The small amount of leftover shoyu-dashi, meanwhile, is good with raw or cooked vegetables; spooned on some poached shrimp, a poached egg, or cold tofu; or used as a dipping broth for warm or chilled soba or somen noodles.
In this recipe, I toss the dressing with earthy sweet potatoes, bitter arugula, and crushed toasted walnuts. It's a hearty, satisfying salad, and one that proves, without a doubt, that you can safely drop the acid for the trip of a lifetime...a flavor trip.