Moscow Mule: the copper mug, the lime, and whether any of it matters
The Moscow Mule is the only cocktail most people associate with a specific vessel. So the obvious question: does the copper mug actually do anything, or is it just a look?
Does the copper mug matter
Partly. Copper conducts heat extremely well, which means the mug drops to the temperature of the drink almost instantly and stays there. You feel that in your hand, and the rim goes cold, so the drink hits your mouth colder than it would from glass. Cold is a real part of how this drink tastes, so it is not nothing.
What copper does not do is change the flavour. Claims about copper reacting with the lime to enhance the taste do not hold up. The mug makes the drink feel colder. That is the honest extent of it.
One thing worth knowing: a mug should be lined on the inside, usually with nickel or stainless steel. Acidic drinks sitting in bare copper can leach small amounts of it, and lime juice is acidic. Any mug sold for the purpose will be lined. If you have inherited an unlined one, use it for something else.
The ice is doing more work than the mug
A Mule is a long drink you sip slowly, and it is mostly ginger beer, so watery ginger beer is the failure mode. Fill the mug properly, and use large ice if you have it. A Sphere Ice Tray at $28 gets you ice that chills without vanishing.
Half a mug of small cubes melts faster than a full mug of large ones. Underfilling is the most common mistake in the whole drink.
The garnish
Lime and mint, and not much of either.
A dried lime wheel sits against the inside of the mug and holds its shape the whole way down, which matters in a drink that takes twenty minutes. A fresh wedge in a mug of ice and ginger beer collapses quickly, and you have already squeezed lime into the drink, so it is adding nothing but bulk.
A slapped mint sprig at the top is optional but good. Lay the sprig on your palm and give it one firm clap to release the oil, then sit it where your nose will find it.
Copper is a warm, dark metal, so pale garnishes read better against it than green ones. This is the one drink where a dried lemon wheel instead of lime looks noticeably better, and tastes near enough the same.
The recipe
Ingredients (per serve)
- 60ml vodka
- 15ml fresh lime juice
- Ginger beer, to top
- Plenty of ice
- F N Lemons dried lime slice, and a mint sprig
Method
- Fill a copper mug or tall glass to the top with ice.
- Add the vodka and lime juice.
- Top with ginger beer and stir once, gently. Stirring hard knocks the fizz out.
- Tuck a dried lime wheel down the side and add a slapped mint sprig.
Use ginger beer, not ginger ale. Ale is sweet and mild; beer is hot and spicy, and the heat is the point of the drink.
Everything we make is handcrafted in small batches here in the Waikato, using real fruit and natural ingredients. Browse the dried citrus range, with free shipping on orders over $100.