A martini is a classic cocktail made from 3~4 parts gin and 1 part dry vermouth. It is then stirred in a mixing glass with ice cubes, strained then garnished with a green olive or a twist of lemon peel. It is most famous for being the drink of choice of James Bond – the most famous spy in the fictional world. Bond frequently orders a vodka martini (vodka instead of gin) and is famous for asking it to be “shaken, not stirred”.
The reason for his preference has never been given in the novels, but that did not stop Bond enthusiasts, martini connoisseurs and even scientists from investigating why Bond may have preferred a shaken martini as opposed to a stirred one.
When you shake a drink with ice, it becomes colder than when it is stirred for the same amount of time. This may be the main reason Bond liked a shaken martini (also called a Bradford), as a martini is typically served as cold as possible.
However, shaking a cocktail has some consequences. The vigorous shaking will introduce more air into the cocktail (“bruising” the drink), which makes it taste sharper and more bitter. The bubbles also makes the drink cloudier and have a different texture. Furthermore, shaking causes the ice to chip (as opposed to the much gentler stirring), which serves to make the drink cloudier and more diluted. Therefore, the shaking essentially makes the drink weaker.
An alternative theory as to why Bond asked for his martini to be shaken is that vodka was often made from potato more than grain prior to the 1960s. Potato vodka has an oilier texture and shaking helps disperse the oiliness and improve the taste.
A biochemical analysis of stirred versus shaken martinis reveal that shaking causes more hydrogen peroxide to break down, meaning a shaken martini leaves half the peroxide left in a stirred martini. The reduced hydrogen peroxide content results in more antioxidants, which has health benefits such as reducing the risk of cardiovascular disease, cataracts and stroke.