A kentucky mule is a Moscow mule with bourbon in place of the vodka, and that one swap changes the drink completely. Vodka lets the ginger do all the talking. Bourbon argues back, and the caramel and vanilla in the barrel meet the ginger somewhere in the middle.
- Three ingredients, no shaker, no syrup, no equipment beyond a glass
- Bourbon and ginger meet in the middle instead of one burying the other
- Ninety seconds a drink, which is why it works for a crowd
- The lime goes to three quarters of an ounce, not a half, which is the fix
- Batches cleanly in a pitcher as long as the ginger beer goes in last
- Copper mug entirely optional, and the reason it is traditional is not what people think
It is three ingredients over a lot of ice, which means there is nothing to hide behind. Good bourbon, a lime you squeezed yourself and a ginger beer with actual heat in it, and the whole thing takes under two minutes to build.
Everything below assumes a glass, a citrus press and cold ginger beer.
What Is a Kentucky Mule
The name is recent, the drink is not, and the definition is looser than most bar lists suggest.
It is bourbon, lime and ginger beer. That is the whole thing. Built over ice, never shaken, and served in whatever is cold and holds ten ounces.
The Kentucky part is the bourbon. Ninety five percent of American bourbon is distilled in Kentucky, which is where the name comes from and nothing more.
Ginger beer, not ginger ale. Ale is a soft drink flavored with ginger. Beer is brewed or heavily infused and it actually burns a little, which is the point of the whole category.
No syrup, no bitters, no muddling. Every one of those has been added by somebody, and every one of them moves the drink further from what a kentucky mule is supposed to be.
It is a highball, not a cocktail in the strict sense. Spirit plus a long mixer, assembled in the glass it is drunk from.
Get those right and a kentucky mule is one of the few drinks that is genuinely hard to make badly.
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Kentucky Mule Versus Moscow Mule
Same structure, different spirit, and the difference is bigger than a substitution usually is.
Vodka is a carrier. A Moscow mule tastes almost entirely of ginger and lime, with alcohol underneath it. That is the appeal, and it is also why it can taste thin.
Bourbon is a participant. Corn sweetness, barrel vanilla and a little oak tannin all show up, so a kentucky mule tastes of two things rather than one.
The lime has more work to do. Bourbon is sweeter than vodka, so the half ounce of lime that suits a Moscow mule leaves this one flat. Three quarters is right.
It takes ice better. Dilution softens bourbon’s edges. A Moscow mule left sitting just goes watery.
And it drinks warmer. The same glass in November makes sense in a way the vodka version does not.
If you want the Moscow version, use the same measures and swap the spirit. Nothing else changes.
Ingredient Notes
Three things, plus ice, and every one of them is worth thinking about for ten seconds. Exact amounts are on the recipe card.
- Bourbon: 2 ounces, at 90 proof or above. The Kentucky Distillers’ Association defines bourbon as at least 51 percent corn, aged in new charred oak, which is where the vanilla and caramel come from. An 80 proof bottle disappears under the ginger.
- Ginger beer: 4 ounces, cold. This is the ingredient that decides whether the drink is good. Look for one where ginger is near the top of the list rather than “ginger flavor” at the bottom.
- Lime juice: three quarters of an ounce, squeezed to order, which is roughly half a decent lime. Bottled lime tastes cooked and there is nowhere for it to hide here.
- Ice: as much as the glass will take, in the largest cubes you have. Small ice melts fast and a kentucky mule goes watery in five minutes.
- Lime wheel: cut thin. You smell it before every sip, which is most of what a garnish does.
- Mint, optional: one sprig, slapped once between your palms. It is not traditional and it is very good in summer.
Nothing here needs a bar spoon, a jigger or a shaker, though a jigger makes a kentucky mule more consistent than eyeballing does.
Choosing the Ginger Beer
This is where nearly every disappointing mule comes from, and it costs nothing to fix.
Heat is the whole point. A good ginger beer should make you cough slightly if you drink it neat. If it tastes like lemonade, the drink will too.
Read the ingredient list. Ginger near the top means real ginger. “Natural ginger flavor” at the end of a list that starts with corn syrup means a soft drink.
Sweetness matters as much as spice. The sweeter brands need the full three quarters of an ounce of lime and sometimes a little more.
Buy small bottles. A liter bottle goes flat after one round and a flat kentucky mule is a sad thing.
Chill it properly. Room temperature ginger beer over ice melts the cubes on contact and dilutes the drink before it reaches the table.
Open it at the last second. Carbonation is doing more work than people realize: the bubbles carry the ginger volatiles up out of the glass, which is why a flat mule tastes duller as well as softer.
Taste the bottle on its own first. Thirty seconds of research settles whether you need three quarters of an ounce of lime or a full one, and it is the only adjustment this drink ever asks for.
How To Make a Kentucky Mule
There is no technique here to speak of, only an order that matters slightly.
- First, pack a copper mug or a rocks glass to the top with the largest ice cubes you have. A full glass melts slower than a half empty one.
- Next, squeeze the lime straight over the ice, about 3/4 ounce, and drop the spent half in if you like the extra oil.
- Then pour the bourbon over the top so it runs down through the ice and chills on the way.
- After that, add 4 ounces of cold ginger beer, poured slowly down the inside of the glass to keep the fizz.
- Finally, give it one gentle stir from the bottom, lay a lime wheel on top and drink it while the ice is still square.
Why Copper Mugs
Copper is traditional for reasons that are half physics and half advertising.
Copper conducts heat fast. The mug takes on the temperature of the drink almost immediately, so it feels colder in your hand than a glass does.
The frost is real. That misted exterior is genuine condensation arriving faster than it would on glass, which is why the photographs always look good.
The rest was marketing. The mug came from a 1940s promotion tying a vodka brand to a ginger beer brand. It is not required and it never was.
Line them if you use them. Unlined copper reacts with acid, so buy mugs with a stainless or nickel lining, which almost all modern ones have.
A rocks glass is fine. Every kentucky mule in these photographs is in an ordinary short glass and none of them suffered for it.
Whatever you use, chill it. Five minutes in the freezer before the ice goes in buys you a noticeably colder drink for the first half of the glass, which is where a highball is at its best.
Making a Batch for a Crowd
This is the drink I make when there are eight people and I do not want to spend the evening behind a counter.
Batch the bourbon and lime only. For eight drinks, combine 16 ounces of bourbon with 6 ounces of fresh lime juice in a pitcher and refrigerate.
Keep it up to 8 hours. Fresh lime juice starts to flatten after that, so squeeze in the afternoon for an evening party rather than the day before.
Set out ice, ginger beer and limes and let people finish their own. Pour about 2 3/4 ounces of the mix over ice, top with ginger beer.
Never batch the ginger beer. It goes flat within twenty minutes in an open pitcher and a flat kentucky mule is not worth serving.
Cut the lime wheels ahead and keep them under a damp paper towel in the refrigerator.
Work out the ice before anything else. Eight drinks want roughly five pounds of it, which is more than a freezer tray produces in an evening, and running short is the one thing that actually ruins a round of mules.
Write the pour on a card and leave it beside the pitcher. People pour far more generously than a jigger does, and a party of eight can get through the batch in twenty minutes without it.
Variations and Substitutions
The frame is spirit, citrus and a spicy mixer, so most of it moves without breaking anything.
- Rye instead of bourbon, which gives you a drier, peppery version that some people prefer outright.
- A bar spoon of maple syrup if your ginger beer is on the dry side.
- Two dashes of angostura across the top, which is not traditional and is excellent in cold weather.
- Blackberries or blueberries muddled in the bottom for a late summer version.
- Non-alcoholic: ginger beer, lime and a splash of strong cold black tea, which mimics the tannin surprisingly well.
- Apple cider in place of an ounce of the ginger beer, for autumn.
If you have limes left over, my homemade lime salt uses the zest and my spicy coconut lime popsicles use the juice.
What to Serve with a Kentucky Mule
Sharp, cold and gingery, so it goes with salt and fat rather than with anything delicate.
- Anything fried, which is what it was built for.
- Chili and a baked potato bar, which is what was on the table the first time I made these.
- Sharp cheddar and salted nuts, if you are pouring before dinner.
- Barbecue of any kind, where the ginger cuts through smoke better than beer does.
- My blood orange cocktail with ginger beer as the second option, so one bottle covers two drinks.
- Or a basil gimlet for anyone at the table who does not drink whiskey.
Here is what people ask when I hand them one.
Kentucky Mule FAQ
Frequently Asked Questions
Ginger beer or ginger ale?
Ginger beer, and the difference is not a technicality. Ginger ale is a soft drink flavored with ginger and it is mild and sweet. Ginger beer is brewed or heavily infused and it has genuine heat. Swap one for the other and a kentucky mule stops being a mule and becomes bourbon and soda. If ale is genuinely all you can get, add a thin coin of fresh ginger to the glass and give it an extra minute.
Which bourbon should I buy?
Something at 90 proof or above, which is where most of the standard bottles sit. Buffalo Trace, Four Roses, Wild Turkey 101 and Old Forester all work and none of them is expensive. An 80 proof bourbon is not bad whiskey, it simply gets buried under four ounces of ginger beer. Save the expensive single barrel for a glass with nothing in it.
Do I need a copper mug?
No. Copper conducts heat quickly so the mug frosts fast and feels colder, which is genuinely pleasant, but the tradition began as a 1940s marketing tie-in rather than as anything to do with flavor. A short rocks glass packed with ice makes an identical kentucky mule. If you do use copper, make sure it is lined, because bare copper reacts with the lime.
More Questions About Bourbon
Good to Know
Can I use whiskey that is not bourbon?
Rye works very well and gives you a drier, spicier drink. Irish whiskey is too soft and gets lost. Scotch, particularly anything peated, fights the ginger badly. Tennessee whiskey is close enough to bourbon that nobody will notice. If you are substituting, taste the whiskey neat first and ask whether it has enough sweetness to stand next to four ounces of ginger beer.
How strong is a kentucky mule?
Two ounces of 90 proof bourbon in a drink that lands around 7 ounces including melt puts it near 12 percent alcohol by volume, so roughly a large glass of wine. It goes down faster than that suggests, because the ginger and lime hide the whiskey almost completely. That is worth knowing before the third one.
Can I make it less sweet?
Yes, and it usually improves. Push the lime to a full ounce, choose a dry ginger beer rather than a soda-style one, and cut the ginger beer to 3 ounces so the bourbon carries more of the glass. A squeeze of lemon alongside the lime sharpens it further without making the drink taste of lemon.
Three ingredients, ninety seconds, and the only decision that really matters is which bottle of ginger beer you reach for. That is why a kentucky mule is the drink I set out when people are coming over.
Kentucky Mule with Bourbon, Lime and Ginger Beer
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Ingredients
The Kentucky Mule
- 1 cup large ice cubes or as many as the glass will hold
- 2 ounces bourbon 90 proof or above
- 3/4 ounce fresh lime juice about half a lime, squeezed to order
- 4 ounces ginger beer well chilled, brewed rather than ginger ale
To Garnish
- 1 lime wheel cut thin
- 1 sprig mint optional, slapped once between your palms
Equipment
- Collins glass or Moscow mule mug
Instructions
Build the Drink
- Pack a copper mug or a short rocks glass right to the top with the largest ice cubes you have. A full glass melts far more slowly than a half empty one, and dilution is the only thing that can spoil this.
- Squeeze the lime directly over the ice, about 3/4 ounce, and drop the spent half into the glass if you want the extra citrus oil.
- Pour the bourbon over the top so that it runs down through the ice and chills on the way.
Top and Serve
- Add the cold ginger beer slowly, pouring it down the inside of the glass rather than into the middle, which keeps far more of the carbonation.
- Give it a single gentle stir from the bottom to lift the bourbon and lime up through the ginger beer, lay the lime wheel on top, add the mint if you are using it, and serve straight away.