In the northern hemisphere, August means the dog days of summer have arrived. In Argentina, winter is in full swing, and the time has come to unearth a potion of sorts that has been maturing anywhere from three days to a full year, depending on one’s commitment to the custom.

August 1 marks the Day of the Pachamama, who the Andean tribes worship as an earth goddess. Indeed, the name “Pachamama” literally translates to “Mother Earth” in Quechua — a language spoken by Indigenous peoples in Peru, Ecuador, Bolivia, Chile, Colombia and Argentina. To celebrate, Argentines of all backgrounds and persuasions drink from a bottle of caño y ruda (sugarcane and rue leaves), which they believe wards off “winter evils,” attracts health and good luck, and repels both envy and hexes. 

Although the Day of the Pachamama is celebrated across South America, this particular ritual is believed to have originated with the Guaraníes native to the Argentine provinces of Misiones, Entre Rios and Corrientes. The tribe believed that the rue-based drink held medicinal properties that could be used to treat parasites and stomach maladies, as well as pains and insect bites. 

Caña y ruda is relatively easy to make on your own. All you need is a clear glass bottle, some white sugar cane or ginger, and a branch of rue, which you can purchase at a verduleria (a fruit and vegetable stand) or plant shop. The taste of the rue leaves can be bitter, especially if they’ve infused the water over a period of several months, so you might like to add a bit of caramel to make the drink go down easier.

According to Argentina’s Ministry of Culture, the beverage must be consumed in a specific way to achieve its intended effect. This involves taking “seven sips, three gulps, one of them long, [before] a full glass,” and always first thing in the morning prior to eating. Those who are new to the custom are in luck: they have a two-week grace period to prepare and drink the concoction.

“Originally, they used liqueurs made with chañar (a kind of shrub), patay (flower-based cake), prickly pears or carobs, to which medicinal roots and herbs were added,” notes the ministry. “With the arrival of the Europeans, the recipe’s ingredients evolved to the ones we know today.”

If you really want to follow tradition, you’re encouraged to make a small libation of the caña y ruda to Pachamama and repeat the word “kusiya,” which means “help me,” twice. Who knows? It just might spare you a nasty winter bug.