As someone who hails from Boston, the land of ridiculous accents, colloquial aggression and forever-available iced coffee, I'm not used to the massive switch from hot to cold drinks that most city coffee shops experience when the temperatures spike back up into the summer ranges. We Massachusetts types simply take our coffee iced, every day, all of the time, in huge styrofoam buckets and laden with heavy cream and undissolved sugar. If you're not crunching into your coffee as it burbles up through your orange and purple striped straw, you're not drinking coffee like a Bostonian. But most of the country isn't crazy like we are. Most coffee shops have to predict precisely when their customers will start demanding plastic cups in lieu of paper, frappuccinos instead of cappuccinos.
You may have wondered why the cold stuff tends to cost more. Maybe you figured it was just due to the extra labor of pouring the hot stuff over ice, or maybe you suspected that coffee shops were swindling those with low heat tolerances out of a few cents. Maybe most shop owners are just coffee purists who think that those who dare to water their cup down with a scoop of ice ought to be punished. The truth is that iced coffee--the good kind--is actually not the easiest thing in the world to brew.
Most shops that serve iced coffee simply pour their regular joe into an ice-filled cup. If they're nice about it, they'll brew a double-strength batch so that you're not drinking watery swill when it's summery out. But higher-end coffee houses will go the extra mile and actually cold-brew their iced coffee. These are the folks that rightfully charge a bunch extra for the frigid drink. It's a whole new ball game, one that requires a lot more time--and a lot more coffee--than simply brewing a hot pot of java.
In order to cold-brew coffee, you've got to let the grounds mix with the water for 12 to 24 hours. After they've mingled for a day or so, you cut the resulting concentrate with equal parts water or to taste. Unlike fresh brewed hot coffee, iced concentrate will stay good up to a week after brewing, allowing a batch to withstand a sudden drop in temperature and demand. It's easier to dole out since it just needs to be poured, not steamed or blended. So as we go forth into warmer weather, keep an eye out for the cold-brewed good stuff--the kind that comes from a pitcher, not a pot--around your usual caffeine haunts.