Shake the flower umbels well, if possible do not wash them, at most hold them under water for a short time. Then place in a bowl and pour apple juice over it (do not cover the stem ends with juice). Cover and let stand for a day, then strain and mix the juice with the preserving sugar. Bring to the boil while stirring. Cook over a high heat while stirring for 1 minute, then pour into glasses and close immediately. Briefly turn the glasses upside down.