This is a better cocktail than the similar but honey-sweetened De Rigueur Cocktail, as unless you have a very full-bodied honey, maple syrup's 'tang' sits...
Love these original cocktails with a few ingredients. I lived in LA when the Brown Derby restaurant was still in business and had a few of these there. Was not a big drinker then, so I did not pay attention to what was used (Bourbon or Rum)
I am a big rum drinker, so will try again using the original recipe. I think the key to using the rum is to make sure it is not a sugar adulterated rum (which eliminates over 60% of the distillers). Although it has funk, thinking on a dark Jamaican.
Best bourbon drink so far, best 3 ingredient cocktail in recent memory. Damn that is good ! I did use 15ML maple syrup for more tang and WoodFords Reserve Bourbon.
I was actually surprised by how good this turned out to be. I was inspired by Roi's comment below and added a (heavy) barspoon of honey vinegar, which really brought more focus and clarity to the drink, without turning it into a sour. I used Yellowstone bourbon (eh). It starts off with maple flavors, and after a brief grapefruit detour, ends with bittersweet bourbon notes. Overall I found it highly enjoyable.
Made again with the exact same specs, but subbing honey for the maple syrup, and I much prefer the maple version. I found the maple to combine with the other ingredients in a way that was both more harmonious and more interesting, while the honey was kind of just there.
I've been enjoying a version of this that incorporates apple cider vinegar (2 ounces bourbon, 1 ounce grapefruit juice, 1/2 ounce each of honey syrup and apple cider vinegar). It's really well balanced.
You claim that the use of honey syrup in the Brown Derby is a 'misguided belief' which stems from the '33 book "Hollywood Cocktails," but the only evidence you've given that maple syrup was in the original recipe is a column published 6 years later in '39, which uses an entirely different spirit and citrus. Seems a little dubious. Made a rather nice cocktail nonetheless.
Perhaps there is an inference in Mr. Difford's review that the "1930 The Savoy Cocktail Book" describes a recipe for a Brown Derby with maple syrup but "when made with honey this is a De Rigueur cocktail"?
Fan of the original, but tried with reposado tequila (and a pinch of salt) in place of the bourbon and really enjoyed the result – like a short, sweet Paloma.