Clean and wash the tomatoes. Peel garlic. Put vinegar, 1/4 litre water, sugar, salt, garlic and bay leaves in a pot and bring to the boil. Remove the pot from the heat and stir in the preserving aid.
Wash the basil, pluck it from the stalks and layer it with the tomatoes in jars. Pour the spice stock over them and let them cool down, then close the glasses. Makes two glasses of 750 millilitres each.