There's a hierarchy in the world of bread soups—a hierarchy of appeal. See, it takes relatively little to convince most people that gazpacho is an appealing idea. Who wouldn't want a chilled tomato soup, loaded with the ripe flavors of summer? The bread in it is almost a footnote. One step down is Italian pappa al pomodoro, a warm tomato soup in which the pieces of bread have softened to a custardy texture. It's a little hard to explain why it's so good, but I've found most people are willing to give it a try if you promise them they won't regret it. (They never do regret it, by the way.)
Somewhere further down the list is ribollita, a Tuscan bread-and-vegetable stew made from leftover minestra...because, let's be honest, anything in which "leftovers" is part of the pitch gets an automatic demotion in terms of desirability. And then there's Portuguese açorda, which most folks have definitely not heard of and, more often than not, are happy to leave it that way.
Very near the bottom, though, comes a cousin of gazpacho called ajo blanco (sometimes spelled as a single word, ajoblanco). It'd be fitting to call it the black sheep of the gazpacho family, except for the fact that it's distinctly white. Its name doesn't do it any favors either, given that it means "white garlic." If I told you I was going to make you a chilled bread-and-garlic soup, how excited would you get, really? (If your answer is "very," you're in the extreme minority.)
So, how can I convince you to add this soup to your summer recipe rotation if it isn't there already? Some people take the easy route by calling this soup "white gazpacho," which is a pretty slick marketing device, and not entirely inaccurate—before tomatoes arrived in Europe from the Americas, ajo blanco was about the closest thing to gazpacho that one was likely to find in Spain.
But I'd like to sell the soup on its own merits. I'd start by explaining that the bread is almost entirely a textural ingredient. Sure, it adds a subtle wheat-y bass note of flavor, but more than anything else, it provides the starch that thickens the soup, acting as a kind of structural backbone.
Next, I would fill in an important blank: The soup may be named for the garlic in it, but the real main ingredient is almonds. The garlic adds complexity and some kick, but it's the almonds that give ajo blanco its soul. Once blended, they release their milk, with its delicate floral and nutty fragrance, into the soup. When it meets the thickening power of the bread, the almond milk takes on an uncanny creaminess—you simply can't believe this is a dairy-free soup (a vegan one, actually!).
For my recipe, I tested a few versions of the almonds: plain blanched (skinned) almonds, toasted ones, and Marcona almonds, a Spanish variety that's usually lightly fried or toasted. My preference was for either the plain blanched almonds, which provide the lightest, freshest, cleanest almond flavor, or the Marconas, which offer just a shade of toasty complexity. The ones I toasted myself, even though they were toasted only lightly, hit the soup with a heavy-handed roasted-nut flavor that I just didn't enjoy. You can maybe make it work if you toast your almonds to an almost imperceptible degree, but otherwise, I'd just stick with plain ones or Marconas.
Back in the old days, the whole thing would have been made with a mortar and pestle, pounding the nuts and old, stale bread together to reduce them to a purée, then working in garlic, water, and olive oil, plus a splash of sherry vinegar to brighten up the richness.
Today, though, you can rely on a blender. If you're using a less powerful one, you may want to pass the soup through a fine-mesh strainer afterward, just to get out any gritty bits. A high-powered blender, on the other hand, can transform it into a velvety-smooth texture in a minute or two, no straining required.
One note on the bread. Historically, most bread soups have been a vehicle for stale bread that otherwise would have gone to waste. But, after lots of testing on this soup and other bread soups, I've found that it simply doesn't matter what you use. This soup works with stale bread, it works with oven-dried bread, and it works with fresh bread. Once the bread is fully saturated with liquid, you cannot tell the difference.
After blending, you'll want to put the soup in the fridge, giving it enough time for the flavors to meld and develop, while the whole thing takes on a refreshing chill.
Here's the last thing to know about ajo blanco: Even after you've made the soup, after you've blended it and chilled it and given it time to settle into itself, if you try it just like that...you likely won't be all that impressed. Some people try to fix this by blending in other ingredients, like cucumber, apple, and more. That can be good, but I suggest trying it in its most basic form first. The key is to hold your judgment until you've eaten the finished, plated soup, because ajo blanco isn't ajo blanco without its fruit garnish.
That's true of a lot of soups—the garnish elevates it from an everyday experience to something special. But with ajo blanco, it goes beyond that. The garnish—usually fresh grapes, but sometimes other fruit, like melon—completes it. Ajo blanco just isn't a fully realized dish until it's studded with juicy, sweet-tart bites.
But, oh boy, do I promise you: Once you try ajo blanco in that state, it'll go right to the top of your cold-summer-soup list.