Glossary: R

Rotovap

Rotovap is short for rotary evaporator. They have been used in chemistry labs for decades and slowly, the world of gastronomy adopted them to make bespoke flavours. For spirit makers and distillers, they represent a unique form of distillation apparatus because they are capable of distilling at very low temperatures.

The reason they are able to do this is that rotovaps work under vacuum. By taking out the atmospheric pressure out from within the sealed system, ethanol can be separated from the liquid in the flask at temperatures as low as 20C. Gin makers use this feature in particular, in order to capture delicate notes from floral and citrus botanicals that would otherwise be lost, cooked or stewed due to the need to heat up in a traditional still.

Reposado

Reposado is a term that refers to a type of Tequila. Legally, Tequila Reposado must be aged in oak between two months and one year.

Raicia / Raicilla

Think of Raicilla as a cousin to Tequila, Mezcal and Sotol. It is also a distilled spirit and it originates from the south western portion of the Mexican state of Jalisco. Like tequila and mezcal, it is a product of the agave plant. 

Raicilla is now protected by a Denomination of Origin and tends to comes from “de la costa” (of the coast) and “de la sierra” (of the mountains). Most of the major producers are from the latter, and their production can be loosely split into two based on the roasting techniques they use. Pit-roasted agave produces a smokier taste, similar to Oaxacan Mezcal, and clay-roasted agave gives the spirit a cleaner, more herbal character. 

Rancio

Rancio is a term used to describe certain wines that have been oxidised or have been exposed to heat. The term is synonymous with a pungent, off-odour but despite this sounding unpleasant - it is not considered a negative trait. It is merely something that’s characteristic of these wine styles.

From a Spirit’s perspective, rancio is something you can pick up in aged Cognac and Whiskies (Rancio Charantais is considered specific to Cognac, which is why it is sometimes referred to as Charente Rancio).

In spirits, just as it is with wine, Rancio is derived through the oxidation of fatty acids within the spirit, which evolving into ketones. This creates mercurial flavour notes that many describe as earthy, buttery or nutty depending on the stage it is at. The phenomenon intensifies over the years, but it would be unusual to experience it in spirits (in particular Cognac) that are less than eight to ten years old.  

Reflux

Reflux is when the spirit vapours in a still recondense back into liquid form and return back to the pot. 

This can take place in small amounts in simple pot stills, and a lot in column stills that can have plates, copper pellets, mesh or other packing to encourage it to happen.