While Delmonico’s as it was no longer exists, the Delmonico Cocktail (as well as its fellow No. 1 and No. 2) does, albeit being not frequently found in cocktail books. It makes no appearance in Boothby’s American Bar-tender (1891) or Kappeler’s Modern American Drinks (1895); the Old Waldorf-Astoria Bar Book (1935) defines it as a dash orange bitters, ½ French vermouth, ½ Plymouth gin, two slices orange peel and claims it was “adopted from the bar of Old Delmonico’s”.
The variations that we find in modern books offer up varying pours of Gin, Brandy, Dry and Sweet Vermouth, and Bitters. As a Vermouth drink, it can be placed around the late 1800s, probably about 1876 according to David Wondrich, who believes it originated at Delmonico’s Madison Square location. Wondrich’s version calls for 0.75 oz Gin and an orange twist; we’ve opted for the more commonly seen 1 oz Gin and a lemon twist.