How the Science of Salt Can Improve Your Tomatoes

20160812-BLT-bacon-lettuce-tomato-tomato.jpg

[Photographs: J. Kenji López-Alt]

There's no comparison between the juicy, intensely tart-sweet flavor of a ripe, in-season tomato and the bland, mealy character of its cold-weather counterpart. But even the very best tomatoes can be vastly improved with only one simple ingredient. That ingredient is salt, and it does more than just season your food—it does science.

To be more specific, salting facilitates osmosis, the process that, to paraphrase Kenji, draws liquids—in this case, tomato juice—from an area of low-solute concentration (the interior of the tomato's cells) through a membrane (the cell walls) and into an area of high-solute concentration (outside the cells). More simply put, in just a matter of minutes, salt will cause tomatoes to release their juices, resulting in fruit that's less watery and more intensely flavored.

And that's not all! Salt stimulates your salivary glands, causing them to produce the saliva that distributes flavor to your taste buds. It also suppresses your perception of bitterness, making that tomato taste even sweeter.

Collectively, these unique traits are what make us such tomato-salting zealots. And, as is true for most zealots, our salting practices come with a few core commandments:

1. Thou shalt drain tomatoes for tossed salads: If you've ever added tomatoes to a salad, chances are you're familiar with the pool of liquid that forms at the bottom of the bowl, sogging up your leaves and watering down the flavor of the entire dish. The answer? Salt the tomatoes before combining them with other ingredients, letting them drain in a strainer or colander for just 15 or 20 minutes. You'll simultaneously intensify their flavor and ensure that the only liquid in the bowl is your dressing of choice. Put it to the test with this mixed-herbs salad or our modernized take on an iceberg wedge salad.

2. Thou shalt drain for-later tomatoes: The same principle applies to the tomatoes in any dish that you plan to prepare more than 15 minutes before serving—think homemade lunches, picnic staples, and so forth.

3. Thou shalt reserve the juices: Make sure to set that colander or strainer over a bowl—the liquid you'll extract is well worth saving. Use it in your next Bloody Mary, or incorporate it into a salad dressing (at your discretion, not the tomato's!). In fact, salting the tomatoes, draining them, and recombining them with their juices is a process that's essential to our deeply flavorful Andalusian Gazpacho (and its faster, easier cousin); our Tomato Coulis; and our classic Tuscan panzanella.

4. Thou shalt not drain for-right-now tomatoes: Planning to dig in right away? Capitalize on the tomato's natural juiciness, and add salt just at the very end. It's a great way to enhance BLTs, breakfast sandwiches, Caprese salads, pan con tomate, bruschetta, and beyond.

5. Thou shalt choose thy type and volume of salt wisely: If you're just salting your tomatoes to drain them, we recommend using kosher salt—a heaping teaspoon for every pound of tomatoes should be plenty. But for tomato preparations you plan to enjoy right away, grab the finishing salt and season to taste. Flaky sea salt will deliver bright pops of flavor and a pleasantly crunchy textural element that kosher and table salts simply can't compete with.