Rum Old Fashioned | A 4 Ingredient Classic Cocktail Made with Decadent Demerara Sugar

This Rum Old Fashioned sweetened with Demerara sugar is the perfect cocktail to sip on chilly nights. It’s a timeless classic that seasoned bartenders savor and yet is simple enough for even the most novice of home bartenders to whip up.

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The Old Fashioned is a classic cocktail and it’s probably surprising that I haven’t posted the recipe here on Girl & Tonic yet. It’s one of those recipes that I have a hard time sitting down to write out because I have so many other recipe ideas swirling around in my head. I’m sure I’ll write it out one day. But for today, we’re gonna be talking about it’s warm & friendly cousin: the Rum Old Fashioned.

As with any cocktail that is spirit-forward, the quality of your rum here will make or break the drink. Normally, I’m all for penny-pinching. I don’t think you have to buy top-shelf alcohol to make a great cocktail. But save your lower-end rums for drinks that use ingredients with stronger flavor profiles, like a Jungle Bird, a Sea Monster, or a Dark & Stormy.

For this Rum Old Fashioned, you’re gonna want to use that nice bottle of golden, aged rum you’ve had stashed away for a while. Or maybe this will be the perfect excuse for you to splurge a little on a good-quality rum at the liquor store. I personally love having a range of spirits on hand for everyday drinks or special occasions.

Now, a traditional Old Fashioned calls for a sugar cube. You can definitely use a sugar cube in a Rum Old Fashioned. However, since we’re going the rum route, it feels too natural to use Demerara sugar. You can make it into a Demerara simple syrup like I did or you can use a teaspoon of it.

If you make the Demerara syrup, you’ll be able to use it in a lot of other cocktails like the classic Mai Tai or the aforementioned Jungle Bird. It’s also incredible in coffee. Demerara sugar has got a great toffee taste to it. You can sub in turbinado sugar, too.

Sometimes it’s tempting to skip the garnish on a cocktail. I’m guilty of it myself. But don’t skip the orange peel in this one. It adds just the right amount of orange essence without overpowering the drink.

It’s also tempting to forego adding bitters to a cocktail, After all, so many recipes just call for 1-3 dashes or drops of them. They make a big difference in any drink, but especially in this one. My friend refers to bitters as “seasoning for cocktails” and she’s right. You *can* skip bitters in a recipe… but it’s like going without seasoning on a chicken breast or french fries. You could… but why?

Plus, a bottle of bitters is inexpensive will last you for years and years. They’re a worthy investment for any home bartender. You can also experiment with other flavors of bitters such as orange bitters, cardamom bitters (I love!), and chocolate bitters. You could even make a Rum Old Fashioned with a couple dashes of chocolate bitters. Mm. Now that sounds nice.

This is also a cocktail that’s made without a cocktail shaker. Traditionally, cocktails that are spirit-forward are mixed and chilled by stirring them in a mixing glass and then straining them into your glass of choice. Here is a really pretty cocktail mixing glass I’ve had my eye on for a while. You can always just use the cup portion of your cocktail shaker. Or just make the drink right in the glass. I won’t tell anyone.

So, what do you prefer: a Rum Old Fashioned or the classic whiskey Old Fashioned? I’d love to hear your preference in the comments!

Ingredients for a Rum Old Fashioned

• 1 1/2 oz aged rum (good quality)
• 1/4 oz Demerara syrup or sugar
• 3-4 dashes of aromatic bitters
• swatch of orange peel

How to Make a Rum Old Fashioned

Add the rum, Demerara sugar or syrup, and bitters to a mixing glass with ice. Stir well to combine and chill. Strain it over a large ice cube in a lowball glass. Twist the orange peel over the drink in order to release the oils. Place the orange peel in the drink. Enjoy.