Bring large pot of water to boil. Cut out the stem section of each tomato, and then mark a shallow X at the blossom end. Immerse the tomatoes, a few at a time, in the water 1 minute, or until the skins just to start slip off. Lift out with a slotted spoon and place tomatoes on a tray. When cool enough to handle, peel off the skin and discard. Cut the tomatoes in half lengthwise. Set a sieve over a bowl, squeeze out the seeds from the tomatoes into it. Discard seeds. Place the liquid in the bowl in a pot with the sugar, water and tomato paste. Coarsely chop the tomatoes and add them to the pot. Gently simmer uncovered, stirring occasionally, for 30 minutes, or until mixture begins to represent a chunky tomato sauce. Puree in a food processor. Cool sauce to room temperature and then freeze in suitably sized containers.