Ideally, you should use those tomatoes which have been picked after ripening and have been partially dried in the sun. Wash them well and pass them through a sieve. Pour the purée into glass bottles with cork stoppers — which incidentally have been boiled and sun-dried — held in place by a fine wire in the form of a cross. Wrap each bottle in a cloth, place them in a large saucepan filled with water and then leave them to boil for an
hour.
After the water has cooled down, remove the bottles, them well and then store them away in a dry place.
