An Irish Mule is a Moscow Mule made with Irish whiskey instead of vodka: 2 oz (60 ml) Irish whiskey, 1 oz (30 ml) fresh lime juice and about 4 oz (120 ml) ginger beer, built over ice in a copper mug and stirred gently. The whiskey brings a warmth and a whisper of vanilla the vodka version never had. Garnish with a lime wedge and a slap of mint, and drink it while it's cold and lively.

That's the whole trick, really. It's one of the easiest cocktails you'll ever make — three ingredients, no shaker, no fuss — and one of the most reliably crowd-pleasing. Here's how to build it properly, and the small choices that separate a great Irish Mule from a flat one.

What's in an Irish Mule?

Three things do the heavy lifting, plus ice and a garnish:

• Irish whiskey — 2 oz (60 ml). A smooth, versatile whiskey is what you want here; something bright enough to sit up over the ginger rather than get buried by it.

• Fresh lime juice — 1 oz (30 ml). Freshly squeezed, always. Bottled lime juice tastes of the bottle, and you'll notice.

• Ginger beer — about 4 oz (120 ml), to top. Ginger beer, not ginger ale — this is the single most important call in the whole drink.

• Ice — plenty of it, and good quality if you can.

• Garnish — a lime wedge and a sprig of mint. Optional, but they earn their place.

How do you make an Irish Mule?

1. Fill a copper mug (or a highball glass) right to the top with ice.

2. Pour in 2 oz Irish whiskey.

3. Add 1 oz fresh lime juice.

4. Top with about 4 oz ginger beer.

5. Stir once, gently, just to bring it together — you want to keep the fizz.

6. Garnish with a lime wedge and a sprig of mint. Give the mint a quick slap between your palms first to wake up the aroma.

Serve it immediately. A mule is at its best in the first few minutes, while the ginger beer is still sharp and sparkling.

Ginger beer or ginger ale?

Ginger beer. Every time. This is the mistake that quietly ruins mules the world over. Ginger ale is a soft, sweet fizzy drink with a faint ginger flavour. Ginger beer is spicier, drier and altogether more grown-up, and it gives the mule its signature kick. Swap in ginger ale and you've made a sweet whiskey soda; keep the ginger beer and you've made a proper Irish Mule. If you can find a fiery, small-batch ginger beer, even better.

Why a copper mug?

Tradition, mostly — but there's a bit of science too. Copper is a superb conductor of temperature, so the moment you pour an ice-cold mule into a chilled copper mug, the metal takes on that cold and holds it, keeping the drink frostier for longer. It also looks the part and keeps your hand off the glass so you don't warm it. That said, you don't need one. A sturdy highball glass makes a perfectly good Irish Mule — the copper is a lovely touch, not a requirement.

How is it different from a Moscow Mule?

Same framework, different spirit. A Moscow Mule uses vodka, which is essentially a neutral, clean canvas — it lets the ginger and lime do all the talking. Swap in Irish whiskey and the drink gains a layer: gentle vanilla, a little malt, a rounder, warmer finish. It's the same refreshing, gingery long drink, but with more to say for itself. If you like a Moscow Mule but wish it had a bit more character, the Irish Mule is your answer.

Ways to change it up

• Add a dash of Angostura bitters for a more complex, grown-up edge.

• Muddle a few blackberries or raspberries in the bottom for a summer-fruit twist.

• A teaspoon of honey syrup rounds it off if your ginger beer is very dry.

• Swap lime for lemon if that's what's in the bowl — it'll be a touch softer and rounder.

The Flying Tumbler serve: The Bird

For our money, the Irish Mule is a job for The Bird. Our single grain is bright, smooth and endlessly sociable — light enough to keep its shape over a good spicy ginger beer, with just enough vanilla warmth to make the whole thing sing. It's the kind of whiskey that was born to be mixed as happily as it's sipped, which makes it a natural in a long, fizzy, lime-forward drink like this.

Build it in a copper mug if you've got one, take it out to the garden, and you've got about the most refreshing thing you can do with a bottle of Irish whiskey on a warm evening. Chase stories, not status — and pour a second one for whoever wanders over.

Frequently asked questions

What whiskey is best for an Irish Mule? A smooth, versatile Irish whiskey works best — something bright and rounded that sits up over the ginger rather than getting lost in it. A light single grain or an easy-going blend is ideal.

Can I make an Irish Mule without a copper mug? Yes. A highball glass filled with ice works perfectly. The copper mug keeps the drink colder for longer and looks great, but it changes nothing about the recipe.

Is an Irish Mule strong? It's a long drink built over plenty of ice, so it drinks easily and refreshingly — but it still contains a full measure of whiskey, so enjoy it responsibly.

What's the difference between a Moscow Mule and an Irish Mule? The spirit. A Moscow Mule uses vodka; an Irish Mule uses Irish whiskey, which adds vanilla warmth and a rounder finish to the same ginger-and-lime base.