Pour the vinegar in a pot. To it add the spices and leave it to come to a boil. Turn the stove off, cover the pot with a lid and leave to cool. Strain the mixture through a gauze.
Pour the tomato juice in a pot and boil it until reduced by 1/3. Add the salt and sugar. Set aside about 1 4/5 cups (450 ml) of the juice. Leave it to cool and dissolve the starch in it.
Add the vinegar to the tomato juice in the pot, then pour in some of the diluted starch after a few min., while stirring vigorously with a whisk. Don't pour in all of the starch because the ketchup will thicken more once it cools.
Take the ketchup off the stove and fill jars with it. Sterilize for 10 min. after boiling point.