When I arrived from the Philippines to the airport in the city of Gondar in northern Ethiopia early last year—before the pandemic started—I was greeted with an intensely flavorful cup of coffee. All arriving passengers were welcomed in the same way. The East African country, historically known as Abyssinia, was already living up to my expectations as the widely regarded “birthplace of coffee.” But it was in the succeeding days, as I trekked the Simien Mountains northeast of Gondar, that I came to truly appreciate the coffee as a source of comfort and warmth on the frigid, rugged peaks...