Clean and wash the tomatoes, cut out the stalk and dice them. Peel and finely dice ginger and onions. Put both in a pot with sugar, salt, pepper, chilli powder and vinegar and bring to the boil.
Let it boil down over medium heat for about 1 hour until thick. Stir from time to time. Season to taste and puree one part with the cutting stick of the hand mixer. Stir in the preserving aid, fill into glasses and close when cold.