An Acid-Adjusted Old Fashioned

This is my recipe for a perfectly balanced Old Fashioned:

  • 2oz bourbon
  • 1 tsp rich (2:1) syrup 0
  • 5-6 drops citric acid solution 1
  • 4 dashes Angostura bitters

Stir for 30 seconds over ice, strain over a fresh cube, add an Amarena cherry, express orange peel, drop a second orange peel in the drink as a garnish.

Do everything exactly as written and you will end up with a spicy, spirit-forward cocktail that goes down way too easily.

Why I do it this way

Disclaimer: the only thing I’m contributing here is citric acid. Otherwise my recipe is basically identical to Morgenthaler’s, which is basically identical to Death & Co.’s. (I’m not sure which came first.) It’s hard to improve on what’s already basically perfect.

So why citric acid? Why does this help?

Acid and sugar balance one another out. You probably know that a can of coca-cola contains a lot of sugar – approximately 40g. You’re less likely to know that it also has a pH of 2.5, meaning it is slightly more acidic than lemon juice. Few people would find drinking straight lemon juice a pleasant experience. Likewise, few people would enjoy drinking 40g of sugar dissolved into 12oz of water. And yet, put the lemon juice in with the sugar and it is a manifestly pleasant experience (lemonade). Likewise it is a manifestly pleasant experience to drink coca-cola (however bad it is for your health). This is because the extreme amount of acid balances the extreme amount of sugar.

Sugar and acid each make it possible to fully enjoy the other.

Enter the old fashioned. We’re not using anything like the same amount of sugar that goes into a coke (thank goodness). But we’re probably adding about ~8g. That’s a non-trivial amount. So, if acid is needed to truly enjoy the sugar for what it is, we should add a bit of acid. That’s it. That was the insight.

This is technically called “acid adjusting” in the bartending community. I stumbled upon this because I was finding that I had to get used to old fashioneds each Fall – when I ritualistically transition from gin- and tequila-based drinks to whiskey-based drinks. Old fashioneds always tasted cloying at first. They were way too sweet. And it would take a few weeks before I acclimated and could really enjoy them with reckless abandon (like I’m doing at the end of each winter).

Unsophisticated old fashioned recipes would have you either muddle an orange slice in the glass, or at least garnish with one. As much as I hated the aesthetics of this – with its cloudy, flocculent appearance, uneven texture, and awkward number of garnishes – I had to admit that the drink tasted great. It was even better than the “sophisticated” old fashioneds I was making with the Morgenthaler recipe. Eventually I realized that – duh – muddling or garnishing with a full orange slice was adding a non-trivial amount of acidity to the drink and that’s what I was missing coming off of a season of margaritas and Tom Collinses.

Enter citric acid. Adding a few drops gives you the flavor-balancing powers of the orange without changing the texture or transparency of the drink. I should emphasize: it doesn’t make the drink the least bit sour. The acidity tempers the sweetness, letting the complex flavors of the bourbon and bitters really shine. And by expressing extra orange oils on the top, it still smells and tastes like you’ve put fresh orange in the drink.


Put two old fashioneds side by side, with citric acid in one. You’ll notice the difference. I don’t think I can go back.

[0] Dissolve 2 parts sugar in 1 part water, by weight. If you want to get fancy you can add some gum arabic as a thickener, but I’ve done side-by-side comparisons with it and I don’t think it really matters. Likewise for different kinds of sugar, e.g. demerara. Plain white sugar and tap water will get you 99% of the way there.

[1] 0.5 oz citric acid powder dissolved in 2 oz water