
Orange blossom water is a clear, non-alcoholic floral water, traditionally distilled from fresh bitter-orange blossoms.
It is a perfume, and a powerful one: a heavy hand turns a drink soapy, and there is no taking it back. Measure it rather than pouring from the bottle. A Ramos Gin Fizz is the classic use, and it sits well with gin, citrus, almond and cream.
Any orange blossom water
Works in the same amount. Some brands are pure distillate and others water with extract, so add it a few drops at a time, smelling as you go.
Rose water
Works one for one. It still gives a floral aroma, but the drink smells of rose.
Leaving it out
Skip it. The drink loses its floral top note but keeps its balance.
Orange extract
Do not use. It smells of zest rather than blossoms and pulls the drink toward orange peel.
Neroli oil
Not a substitute. This essential oil, made mostly for perfume, is far too concentrated.
Sealed, dark and cool, it keeps for a year or more. It fades rather than spoils, so an old bottle needs a heavier hand.
Opal
London dry gin