- Castor Sugar – castor sugar (sometimes spelled caster sugar) is finely ground granulated sugar. It is not as fine as confectioners’ sugar, as it does have a little grit to it, and is not powdery. So, in terms of texture, it falls somewhere between granulated sugar and confectioners’ sugar.
- Hercules – Hercules liqueur, a now-defunct ingredient mentioned in vintage cocktail recipes like those in The Savoy Cocktail Book, was a red wine-based aperitif infused with yerba maté and other unknown herbs. It was once thought to be an absinthe substitute, but research points to its similarity to vermouth, with added herbal and caffeine-like qualities. Efforts to replicate it have involved creating yerba maté-infused aperitifs, though no commercial reproductions exist. Its exact original flavor remains elusive due to a lack of available samples.
- Plymouth Gin – Plymouth Gin is a smooth, slightly sweeter, and earthier gin style produced exclusively in Plymouth, England, known for its balanced flavor and ties to classic cocktails like the Martini. A good substitute for Plymouth Gin in cocktails would be a mild, less juniper-forward gin like Hayman’s Old Tom or a softer London Dry Gin such as Beefeater, which offers a similar balance without overwhelming botanical intensity.