Why It Works
- Oven-drying fresh bread produces a better texture than using stale bread.
- Salting and draining tomatoes produces more flavorful tomato chunks.
- Adding tomato juice to the dressing makes a flavor-packed vinaigrette.
When the temperature dial hits 107°F in my San Mateo backyard it means only one thing: salad for dinner.
The fact that my neighbor down the street was gone for the weekend and had a hyperactive garden overflowing with tomatoes narrowed down my selection considerably. I'd already Caprese'd myself out, so panzanella it was. The classic bread and tomato salad manages to be fresh and summery, but still hearty enough to eat as lunch or a light supper.
Though it's got a reputation as a Tuscan dish, bread salads are not uncommon elsewhere in the Mediterranean. And let's get one thing straight: panzanella is not a tomato salad with bread; it's a bread salad flavored with vegetables.
Bread has been a staple food in the Mediterranean region for millennia, and even though they didn't have modern preservatives, they found ways to preserve it, such as drying it out, so it could last for weeks or even months. Dried, stale bread was as common as fresh. Folks developed creative ways to use their loaves; think of it as the way we might use dried pasta or instant ramen. Dishes like panzanella and gazpacho (which is a bread soup, not a tomato soup!) were the result.
Tomatoes didn't make their way into the classic panzanella recipe until the 16th century at the very earliest (since tomatoes didn't exist in Europe until they were brought back from the Americas), and it's more likely that they arrived far more recently. Writing on panzanella in a 16th-century Italian text, the Florentine painter and poet Bronzino says:
"Un'insalata di Cipolla trita con la porcellanetta e cetriuoli vince ogn'altro piacer di questa vita."
That is: "A [bread] salad made with chopped onions, purslane [a type of wild succulent lettuce], and cucumbers surpasses all other pleasures in this life."
According to the fabulously well-researched* 1999 website FoodTimeLine.org, we in the United States had no clue what panzanella was until the late 1970s. Imagine: most folks in the US were exposed to Attack of the Killer Tomatoes before they were exposed to panzanella!
*Not to mention fabulously Web 1.0.
The panzanella salad has come a long way since then, to the point that it's now an essential recipe of summer for anyone with access to good quality tomatoes. (And let's get another thing straight: good tomatoes are the only kind of tomatoes this salad should be made with.)
Unlike a Caprese salad, in which I strongly believe that anything beyond tomato, basil, mozzarella, olive oil, salt, and pepper will detract from the experience and simple purity of the dish, a panzanella salad can be made with any number of vegetables.
I enjoy making a good grilled-vegetable panzanella, and in the spring I'll make a panzanella with asparagus. Heck, we've even got a recipe for banhzanella, a panzanella salad with the flavors of a banh mi sandwich.
But for today, we're sticking with the modern classic: tomatoes, basil, and bread in a light vinaigrette. How we optimize that salad comes down to the way we treat our ingredients.
Dry Bread Versus Stale Bread: Which is Better in Panzanella Salad?
Bread is the focus of the salad, so bread is where my recipe testing started. To begin my testing, I used a very basic panzanella method: I tossed chopped tomatoes, basil, and cubed bread together in a large bowl with salt, pepper, olive oil, and vinegar. Simple and delicious, but not optimal.
Whether you're making bread crumbs, stuffing, or panzanella, most bread-based recipes will call for stale bread. But what does that really mean? Well when it's left sitting out, bread will certainly lose moisture. Drying often goes hand in hand with staling, but the two terms are not synonymous.
Drying is when bread loses moisture. The basic structure of bread will remain more or less the same, but because moisture provides pliability, the bread will become crisp. Think, toast you've left in the toaster oven a little too long.
In fresh bread, starch molecules are inflated with water, like little water balloons. Staling occurs when water molecules migrate out of those starch molecules and into the interstitial spaces within the bread, causing the starch molecules to re-crystallize and form a rigid structure.
Stale bread is tough and leathery, and will become that way regardless of whether moisture actually leaves the loaf entirely. Bread will stale even when it's wrapped in moisture-proof plastic, and as we discovered in Daniel's article on whether refrigeration is bad for bread, it stales fastest at cold temperatures, just above the freezing point of water.
So when a recipe calls for "stale bread," what exactly does it mean? Does it mean actually stale, or simply dry? Or perhaps stale and dry?
To figure this out, I made my basic panzanella salad using the exact same bread (a loaf of ciabatta) stored under four different conditions:
|Moist||Fresh-baked bread||Bread wrapped tightly in plastic, stored for 1-2 days.|
|Dry||Fresh bread toasted in oven||Bread left unwrapped, stored for 1-2 days.|
I also tried making my salad by soaking bread in water and squeezing it out before dressing it (a commonly recommended method).
The wet-bread technique I dismissed right away. While it did help the dried bread revive a little, it also completely washed out any flavor. My vinaigrette's going to be the only thing to flavor my salad, thank you very much.
Of the other samples of bread, the worst was the bread that was stale but not dry. It was simultaneously wet and mushy while also being tough and leathery at the core, no matter how long I let it rest in the dressing.
The fresh bread was the next worst, very quickly losing all of its texture and turning to mush. Of the two dried batches of bread, I found the most pleasant to eat by far was the bread that was dried but not stale.
This makes sense: I came to a very similar conclusion with my Thanksgiving stuffing recipe. Bread that remained un-dried, whether fresh or stale, simply absorbed too much moisture.
This is good news, because it means that your panzanella salad doesn't require much forethought. There's no need to leave out a loaf of bread so that it actually gets stale before you start.
I also found that bread that was only very lightly toasted and dried had the best overall texture: soft and edible, but crisp around the edges. About 15 minutes in a 300°F (150°C) oven is plenty of time.
And for those times when you have a loaf of already-stale bread that you want to get rid of? Well, turns out that once you add the toasting step, even fully staled bread will refresh itself enough to make a very decent panzanella.
Salting the Tomatoes Intensifies Flavor in Panzanella
Next, I turned my attention to the tomatoes. Tossing the tomatoes directly with the bread is good enough, but I wondered whether I could coax a little more concentrated flavor out by salting and draining them.
Salting draws liquid out of tomatoes through the process of osmosis—that is, the tendency of a liquid (tomato juice) to migrate across a membrane (the tomato's cell walls) from an area of low solute concentration (within the cells) to an area of high solute concentration (outside of the cells). In other words, salt draws out the water in tomatoes, which makes each piece of tomato more flavorful.
Conveniently, this process takes about 15 minutes—exactly the same amount of time that bread takes to toast in the oven, and incidentally, the same amount of time it takes me to polish off a small, cold glass of wine.
The liquid that gets pulled from the tomatoes, while not quite as flavorful as the actual tomato that's left behind, still has plenty to offer.
Whisking this tomato juice into my vinaigrette was an instant upgrade. The salad ended up with plenty of ambient tomato flavor, punctuated by chunks of concentrated, extra-tomato-y pieces.
Addressing a Dressing: Making the Vinaigrette for Panzanella
With the tomatoes and the bread tended to, the only thing remaining was to address the vinaigrette. Until now, I'd been keeping things nice and simple with plain olive oil and vinegar, but it could do with a bit more tinkering.
From my previous exploration of how to make a vinaigrette for a simple salad, I knew the most important part is the ratio of oil to water-based liquid. Get that ratio wrong, and your vinaigrette will break, making foods taste wet and greasy. And since I was adding so much liquid in the form of tomato juice, raising the olive oil content was essential.
As for flavorings, some finely minced shallots and garlic worked perfectly with the hearty bread, and a small dollop of Dijon mustard went a long way toward ensuring that the vinaigrette stayed smoothly emulsified as I tossed the salad. It's not a traditional Italian ingredient, but hey, go back far enough and neither are tomatoes, right?
This is the kind of salad you want to take your time eating—not just because hot weather demands you take a moment to relax, but because the bread will continue to change texture as you eat your way through it.
The result of my experiment was a panzanella with the most intense tomato flavor of any I've ever had, and a texture that straddled the lines between tender and crisp, moist and meaty. It might not be how the ancient Romans ate their bread and onion/cucumber/[insert ancient Mediterranean vegetable here] salads, but I'd imagine even the most battle-hardened centurion would have trouble saying no to this modern classic.
This classic Italian panzanella, a bread and tomato combo that is peak summer, manages to be fresh and seasonal, but still hearty enough to eat as lunch or a light supper.
2 1/2 pounds (1.1kg) mixed ripe tomatoes, cut into bite-size pieces
2 teaspoons (8g) Diamond Crystal kosher salt, plus more for seasoning (use half as much if using table salt)
3/4 pound (340g) ciabatta or rustic sourdough bread, cut into 1 1/2–inch cubes (about 6 cups bread cubes)
10 tablespoons (150ml) extra-virgin olive oil, divided
1 small shallot, minced (about 2 tablespoons)
2 medium cloves garlic, minced (about 2 teaspoons)
1/2 teaspoon Dijon mustard
2 tablespoons white wine vinegar or red wine vinegar
Freshly ground black pepper
1/2 cup (1/2 ounce) packed basil leaves, roughly chopped
Place chopped tomatoes in a colander set over a bowl and season with 2 teaspoons (8g) kosher salt. Toss to coat. Set aside at room temperature to drain, tossing occasionally. Drain for a minimum of 15 minutes.
Meanwhile, preheat oven to 350°F (180°C) and adjust rack to center position. In a large bowl, toss bread cubes with 2 tablespoons (30ml) olive oil. Transfer to a rimmed baking sheet. Bake about 15 minutes, until crisp and firm but not browned. Remove from oven and let cool.
Remove colander with tomatoes from bowl with tomato juice. Place colander with tomatoes in sink. Add shallot, garlic, mustard, and vinegar to bowl with tomato juice. Whisking constantly, drizzle in remaining 1/2 cup (120ml) olive oil. Season dressing to taste with salt and pepper.
Combine toasted bread, tomatoes, and dressing in a large bowl. Add basil leaves. Toss everything to coat and season with salt and pepper. Let rest 30 minutes before serving, tossing occasionally until the dressing is absorbed by the bread.
Use a hearty, open-structured bread, like ciabatta or sourdough.