While traveling through Quito, Ecuador, standish was intrigued by the unusual way the owner of a hostel prepared coffee. "Basically she had a tall, glass, refrigerated decanter of thick, syrupy coffee that was possibly slightly sweet," says standish. "You simply added this to hot water with or without milk to a desirable proportion." This elixir wasn't in a commercial bottle, and seemed to be a homemade preparation, though Alan408 notes that commercial instant coffee comes in liquid as well as granulated and powdered forms.
The concentrated liquid preparation that standish mentions reminds John E. of the concentrated cold-brew coffee he likes to make and dilute with cold milk over ice, or with hot water—though it doesn't have the syrupy, gel-like texture of the stuff standish remembers. "Cold brewed coffee is quite strong but seems to be less bitter with less acid," he says. "I put a pound of ground coffee into a kettle and pour 12 cups of water over it and let it steep for 24 hours in the refrigerator. After straining the coffee, I put it into .5 liter water bottles and freeze it for future use."
Discuss: Strange coffee prep while traveling?