So complete was the break in American mixology that it is possible that the San Francisco Bitters Company (actually from San Diego, apparently) believes it to be true when they state that Boonekamp bitters were “unavailable for decades.”
Actually, Boonekamp bitters have been available in the U.S.A. for as long as I have been paying attention – and undoubtedly a lot longer.
The lore goes that a doctor Kamp, or Boonekamp, created a medicinal bitters in the Netherlands centuries ago. Boonekamp bitters seem never to have been the trademark of a single company. The fact is that many brands of Boonekamp bitters have been, and are still, available. Underberg and Kuemmerling are the leading brands of Boonekamp bitters, and both are available in the U.S.A. Both Underberg and Kuemmerling were labeled “Boonekamp” a century ago. Neither has changed their formula. They have both just dropped the “Boonekamp” moniker — much the same way that Disaronno has dropped the word “amaretto” and Cointreau has long ago dropped the word “Curaçao.”
The above passage is from Kuemmerling’s current press kit.
All of the above are currently-available Boonekamp bitters. Boonekamp bitters from their real, living tradition are most commonly sold in single-serving bottles of 20 ml. (2/3 fl-oz.) each. They are digestive in that dose. They are not meant to be dashed out in small amounts like in the case of Angostura aromatic bitters (San Diego/Francisco Bitters Company got that wrong, too).
To make a Boonekamp Cocktail the way that American bar-tenders sometimes did before prohibition, chill a cocktail goblet and prepare a strip of lemon zest. Into a glass mixing tumbler pour 1 small bottle (1/3 jigger, 20 ml., or 2/3 fl-oz.) of any good brand of Boonekamp bitters, add 2/3 of a jigger (40 ml., or 1-1/3 fl-oz.) of rye whiskey and a teaspoon of fine sugar (or 1/4 fl-oz. one-to-one simple syrup) and method ice. Some people might like more sugar or syrup. Stir this until completely cold and strain the drink into the chilled cocktail goblet. Garnish by twisting the lemon zest over the drink and dropping it in. Serve the drink.
But back to the bitters. All of the above brands are more like each other than the San Diego Francisco Bitters Company so-called Boonekamp bitters is to any of them. I consider the San Francisco/Diego product an outlier from the tradition. I would not be surprised if its formula came from some druggist’s or chemist’s old book that included recipes meant to approximate famous products. If so, the book in question has led someone astray. That would suggest that they never themselves sampled mainstream Boonekamp bitters.
If you want Boonekamp bitters that are most reliably like those indicated occasionally in American drinks from a long time ago, get Underberg or Kuemmerling. They are both Boonekamp bitters that have been made the same way throughout the past hundred years. Underberg is available at Bevmo, and both it and Kuemmerling are available at Alpine Village in Carson, California.