COLLEGE PARK, Md.  The power drink of the moment costs 20 times as much per ounce as Coca-Cola, comes in a tiny bottle and tastes so bad that most people hold their noses and down it in a single gulp.

Despite all that, sales of “energy shots” are soaring in the middle of a recession. The two-ounce drinks, which give people a concentrated dose of caffeine, B vitamins and amino acids, were all but unheard-of four years ago. Today they are the hottest drink category in the country, with sales expected to almost double this year from last, to about $700 million.

The shots are meant for people who want a jolt of caffeine without having to drink a big cup of coffee or one of the 16-ounce energy drinks that have become ubiquitous. They go down fast, more like medicine than a beverage. That is part of the appeal to their most devoted consumers: students cramming for exams or partying into the night, construction workers looking for a lift and drivers trying to stay awake.

Near the University of Maryland the other day, students thought nothing of paying $3 or more for a shot. That is $1.50 an ounce; at that price, a 20-ounce bottle of Coca-Cola would sell for $30.