prior to heinz (and his fellow innovators), commercial tomato ketchups of that time were watery and thin. this was due to the use of unripe tomatoes. those tomatoes were low in pectin. they were less vinegary than modern ketchups. by pickling ripe tomatoes, the need for benzoate was eliminated. there was also no spoiled ketchup or loss in flavor. the changes also helped make it an important american condiment according to some experts.