The word cocktail is vital when ordering in all except the grandest, smartest bars and restaurants. If you simply ask for a martini, you might get Martini vermouth.
This most famed of alcoholic drinks is a mixture of gin and dry (non-sweet) vermouth, itself a herby-spicy aperitif, originally from Italy. And there the complications begin. Quite which gin and quite what proportion of vermouth has been, and is, and will be a constant pursuit; the goal is a martini cocktail that is exactly what you want it to be. Some add a good slug of vermouth, some add a mixture of dry and sweet (red) vermouth and others argue for a proportion of 3:1, 5:2, 5:1, 7:1 ad infinitum. Find a gin that thrills you with the flavours of its aromatic inclusions and you might not want to add much vermouth at all, perhaps merely rubbing a finger wetted with vermouth around the inside of the glass, or opening the bottles in separate rooms and introducing them in a loud voice. Whatever proportion of one to the other that you choose is correct.
If you order a dry or a very dry martini cocktail it should come with very little detectable vermouth.
Wherever there is gin and vermouth and ice.
Choose the best
The best is entirely up to you, according to the style of gin you like best. There are also variations of dry vermouth. But a martini cocktail must be shaken with ice and served in a chilled glass. Straight up means served without ice in the glass; on the rocks means there will be ice in the glass. Beware the American propensity to serve over mountains of ice, which dilutes the taste severely.
Actually, a pre-mixed martini cocktail stores remarkably well and does not deteriorate even if transported in a Thermos flask. Yet somehow it tastes better for you having heard it shaken with ice and then poured and sipped at once.
Martini cocktails, dry or otherwise, should be ordered with an olive or with a twist – a sliver of lemon zest that is twisted directly over the cocktail after it has been decanted into the glass, which coats the surface with a veil of lemon oil. The classic V-shaped glass with a wide mouth is part of the martini cocktail ritual; perhaps this is because you must be very careful to hold it firmly and not to spill.
There are many variations, some old, some new. A dash of orange bitters was once common and is highly recommended: a dirty martini has a splash of the salty water in which olives are stored. A 21st century version might use English pink gin, in which raspberries have macerated to give colour and taste.