For years, researchers in Colombia have been engaged in a little-known battle against a disease that could disrupt coffee drinking everywhere.

If you landed in Bogota in the 1960s, one of the first things you would have probably seen outside the airport was a giant billboard. In a slightly menacing tone, it said: “Coffee rust is the enemy. Don’t bring plant materials from abroad”.

It was one of the first warnings about a foe that has been threatening Colombia’s coffee trade ever since.

Coffee rust is a disease with the power to cripple, or even wipe out, the country’s national product, the base of one of its biggest industries, and one of its most important sources of foreign currency. Last year alone, its coffee exports were worth $2.4bn (£1.8bn), and was 7.7% of all goods the country sold overseas. That makes Colombia the third largest producer of coffee in the world. In other words, if rust takes hold there and global supply dwindles, it will affect the price of the coffee we drink everywhere.

That’s why for the past few decades, Colombia’s scientists have been engaged in a little-known battle with the disease, staged from a small laboratory deep inside the mountains of Colombia’s coffee axis.

The question is, can Colombian coffee’s distinct flavours survive intact?

Coffee rust has plagued farmers for more than a century. When a tree gets infected by it, its leaves produce a brown, thin powder when scratched, pretty much like iron rust. The disease, caused by the fungus Hemileia vastatrix, also de-colours the bush’s leaves from a bright green to a brownish yellow. In the end, the tree loses all its leaves, as well as its ability to produce beans.

If left unattended, the disease can have dramatic consequences. In the late 19th Century, Sri Lanka, the Philippines, and other countries in Southeast Asia were the major exporters of coffee in the world. In a matter of decades, the disease meant they practically stopped growing it.