The arrival of the humble espresso marked a dramatic shift in the way people consumed caffeine across the world, and when espresso and espresso-based drinks became popular in the United States, coffee culture was forever changed. For this week’s Please Explain, we are talking all about espresso: the history of espresso, the technique of making espresso, as well as how and why it has taken off in this country. We will be talking to Erin Meister, a writer and journalist who has spent 14 years in the coffee industry, and Erin McCarthy, a technician at Counter Culture who has worked as a barista and trainer for years, and in 2013 was the first American winner of the World Brewers Cup Champion.