Blanch the bitter almonds and grind them in a mortar with 1 tablespoon of sugar (taken from the 650 g).
Bring the water with the sugar to a boil in a saucepan and cook while stirring until the sugar is completely dissolved. Let cool down.
Put the bitter almonds, the cooled sugar syrup and the floral water in a glass. Leave in the sun for 10 days. Then fill up with 500 ml Metaxa and immediately filter through a sieve lined with a paper filter. Store in a serving bottle.