This bitter vermouth-style French apéritif is now subject to a certain amount of debate due to a recipe change in the 1970s which altered the flavor and reduced the proof. Can the current version properly create the drinks from pre-change recipes? And if not, what's the best alternative?
Consensus among cocktail geeks seems to be that the current version, while nice and all, isn't the same animal. A leading candidate, Torani Amer, doesn't replace it. The solution proposed is to make your own, with Jamie Boudreau's recipe being well-regarded.
However, should you find a current bottle of Amer Picon (as we did at Gerry's in Soho, London) it's a thoroughly enjoyable beverage and quite mix-worthy. It may not make a drink like the original version, but it's a great ingredient nonetheless to bring herbal, bitter and orange notes to a drink.