The temperature dial hit 107°F in my backyard in San Mateo last week, which meant only one thing for that Indian summer evening: salad for dinner.
The fact that my neighbor down the street was gone for the weekend and had a backyard overflowing with tomatoes from a hyperactive raised-bed garden narrowed down my selection considerably. I'd already Caprese'd myself out, so panzanella it would be. The classic bread-and-tomato salad manages to be fresh and summery, but still hearty enough to eat as a light supper or lunch.
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. You can see the root of the Latin word for "bread"—panis—right there in the name.
Bread has been a staple food in the Mediterranean region for millennia, and that ancient bread didn't have preservatives, which meant that folks had to find creative ways to reuse it. 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 dish 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 than that. 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 here 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 salad has come a long way since then, to the point that it's now an essential recipe of the 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 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 only detract from the experience and simple purity of the dish, a panzanella salad can really 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: They Are Not the Same!
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 quite 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, certainly, when it's left sitting out, bread will lose some 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 the bread will remain more or less the same, but because moisture provides pliability, the bread will become crisp. Think: toast that 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 will be tough and leathery, and will become that way regardless of whether that moisture actually leaves the loaf entirely. Bread will readily stale even when it's completely 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 a day or two.|
|Dry||Fresh bread toasted in the oven.||Bread left unwrapped, stored for a day or two.|
To double up on this testing, I also tried making my salad by simply tossing the bread with the vegetables and vinaigrette, as well as by soaking the bread in water and squeezing it out before dressing it, a commonly recommended technique.
The wet-bread technique I dismissed right off the bat. While it did help the dried bread revive a little, it also completely washed out any flavor. My vinaigrette's gonna 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 that 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
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 of them 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 tomato juice, which effectively makes each piece of tomato, ounce for ounce, more highly concentrated in flavor.
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.
I realized that with this one salting and draining step, I could kill two birds with one stone. By using that extracted tomato juice to bulk up my basic vinaigrette, I could make enough dressing to completely saturate and soften up that dried bread—only this time, instead of being flavored by plain old water, the bread would be absorbing fresh tomato juice.
Whisking that tomato juice into my olive oil– and vinegar-based 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 that 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 both wet and greasy. And since I was adding so much liquid in the form of tomato juice, raising the olive oil content was also 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 that you take a moment to relax, but because that bread will continue to change texture as you eat your way through it.
The result of my experimenting 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 minime to this modern classic.