The Technique
Slice your tomatoes and lay them on a plate or cutting board. Season them generously with flaky sea salt — and optionally a crack of black pepper — and let them sit for five minutes before building the sandwich. Pour off any expressed liquid before adding the tomatoes to the bread. The difference in flavor is startling.
Why It Works
Osmosis draws water out of tomato cells when salt is applied, which concentrates the remaining sugars and glutamates. The tomato that emerges from those five minutes has amplified flavor — sweeter, more savory, more complex — and has shed some of its excess water, which means it won't turn your bread into a soggy mess. The salt also seasons the tomato through and through rather than just sitting on the surface the way it would if you salted the finished sandwich.
When to Use It
Every single time you put a tomato on a sandwich. Even with a perfect in-season heirloom, this step improves the result. With a winter grocery-store tomato, it's the difference between edible and good. The technique also applies to tomatoes on bruschetta, caprese salads, and pasta sauces. Once you start salting your tomatoes separately, you won't stop.
Pro Tips
- Flaky salt (Maldon, Jacobsen) works better than fine table salt — it seasons without over-salting
- Five minutes is the sweet spot; more than ten and you start losing too much texture
- Season both sides of each slice for even penetration
- Pat dry with a paper towel before use if the tomatoes weep heavily