3 Glasses Gin. (1 1/2 oz Plymouth Gin)
2 Glasses Orange Juice. (1 oz Blood Orange Juice)
1 Glass of Cointreau. (1/2 oz Cointreau)
A little Sugar. (very little caster sugar)
Add a little Orange-flower water. (drop orange flower water)
Shake and serve.
Of course, re-doing this for one by dividing 2 oz Glasses in half and then dividing in half again. Hey, I can enjoy a drink and a half.
The Opal is not entirely unpleasant, though far more ginny and a bit harsher than would be popular in a modern cocktail. I think part of it might be the heat of the Cointreau.
No idea why it is called the Opal, as even with regular orange juice this would bear no resemblance to those gold-green gems.
This post is one in a series documenting my ongoing effort to make all of the cocktails in the Savoy Cocktail Book, starting at the first, Abbey, and ending at the last, Zed.