Use a very sharp serrated knife and gently saw through the tomato skin first, then slice through the flesh. Avoid applying downward pressure.
Chopping a tomato without losing too much juice relies on minimizing cell damage. A dull knife will crush the tomato, releasing its juices. Here's a step-by-step guide:
Choose the Right Knife: A serrated knife is ideal because the teeth grip the skin and allow you to saw through it without applying excessive pressure. A very sharp chef's knife can also work, but requires more skill.
Prepare the Tomato: Wash and dry the tomato thoroughly.
Slice the Tomato: Gently saw through the skin using a back-and-forth motion. Avoid pressing down hard. Once the skin is pierced, continue sawing through the flesh.
Dice (Optional): If you need diced tomatoes, slice the tomato into rounds first. Then, stack a few rounds and cut them into strips. Finally, cut the strips crosswise to create dice.
By using a sharp knife and a gentle sawing motion, you'll minimize cell rupture and keep more of the tomato's delicious juice inside.
Chill your tomatoes before chopping. Cold tomatoes are firmer and easier to cut cleanly, resulting in less juice loss.