Collect the blossoms in the morning when they are fully open. Clean thoroughly and drain. For a more delicate flavor, separate the petals from the green base.
Bring the water to a boil and pour it over the flowers in a large pot. Cover and let steep for 24-48 hours.
Peel the rind off lemons and oranges. Remove white pith, which will add bitterness. Slice the remaining fruit. Add the orange and lemon peels to the flower-water mixture and bring to a boil.
Remove from heat, strain out solids, then add the sugar, stirring until it is dissolved. Allow to cool.
Add the remaining fruit slices, yeast, and cover with cheesecloth to ferment. When the mixture has stopped bubbling (anywhere from 2 days to three weeks), fermentation is complete.
Strain the liquid through several layers of cheesecloth and transfer to sterilized bottles.
Cork the bottles and store in a cool, dark place for at least six months before drinking for best flavor.
