Bring several cups of water to a voil in a large saucepan or soup pan. Place whole tomatoes in boiling water just long enough to split and loosen their outer skin. You may have to do this in batches. Once the skins are loose, remove the tomatoes from the boiling water and drop them in a bowl of ice water. when the tomatores are cool enough to handle, loosen the skins with your hands. Quarter the tomatoes and remove the hard inner core.