Red wine vinegar
Cut half the tomatoes, cucumber and onions into small pieces and transfer to a combine. Add red pepper and chop to a puree condition. Put in a bowl.
Add tomato juice, chopped cilantro leaves, vinegar, olive oil and a few drops of Tabasco. Mix well.
Remove the seeds from the remaining tomatoes and cut into small cubes. Also chop the cucumber and onion. Add everything to the soup. Season with salt and pepper and place in refrigerator to cool.