Notes from Cook's Illustrated: The key to fresh tomato flavor in our creamy gazpacho Andaluz recipe was salting the tomatoes and letting them sit to release more flavor. We then followed the same process with the other vegetables—cucumber, bell pepper, and onion—and soaked the bread, which we used to thicken the soup, in the exuded vegetable juices. A final dash of olive oil and sherry vinegar further brightened the flavor of our gazpacho, and a diced-vegetable garnish made our creamy gazpacho recipe look as fresh as it tasted.
For ideal flavor, allow the gazpacho to sit in the refrigerator overnight before serving. Red wine vinegar can be substituted for the sherry vinegar. Although we prefer to use kosher salt in this soup, half the amount of table salt can be used. Serve the soup with additional extra-virgin olive oil, sherry vinegar, ground black pepper, and diced vegetables for diners to season and garnish their own bowls as desired.