A National Coffee Association report indicates that as of 2017 coffee drinking among the youth has been sharply on the rise. The two big trends: single-cup brewers and a rise in gourmet coffee varieties.

The latter is part of what's called the second and third waves of coffee. Coffee had initially been a drink for aristocrats and intellectuals, with coffee facing legal challenges (including outright bans, such as under Frederick the Great in Prussia from 1777 until his death in 1786) for a variety of reasons: sending too much money to imports instead of the local economy, keeping it out of the hands of the poor, challenges based on its status as a stimulant, or concerns that coffeehouse culture provided a place for seditious and radical behavior to foment. Murad IV of the Ottoman Empire probably went the farthest: as the Muslim elites became concerned that these cheap non-alcoholic "taverns" would provide gathering places for different social classes who could erode the traditional social order, coffee was made illegal and drinking it punishable by death. It took centuries for coffee culture to fully return to the Ottomans.

The "first wave" of coffee is the 19th century. The Boston Tea Party made coffee the patriotic American beverage of choice (much like how the revolution in general made local whiskey the patriotic American liquor) and it quickly traveled across the continent as pioneers, miners, cowboys, and soldiers needed their wake-up juice. This led to a massive industry forming to make coffee cheaper and easier to produce; Arbuckle in 1864 created the first mass market pre-roasted coffee beans (using an egg and sugar glaze to preserve the beans' flavor and aroma after roasting), as well as Folgers producing tins of pre-ground coffee that could just be combined with hot water. Instant coffee followed in the coming decades, culminating in freeze-dried coffee in the 1950s, and vacuum packaging for even better freshness in the 1900s.

Electric percolators combined with easily preserved roast beans and pre-ground coffee made coffee very cheap and easy to make, but it also sacrificed a lot of the quality. Your coffee ended up being sort of the bare minimum of palatability, with most brews tasting the same regardless of brand. Except for a small number of connoisseurs and coffeehouses appealing to them, coffee was a generic bitter jolt of caffeine optionally doused in sugar and creamer to make it taste better. While some youths did drink coffee (especially in countries like Cuba and Brazil where coffee is given even to toddlers), it was generally unappealing, especially as children are much more sensitive to bitterness than adults.

The "second wave" of coffee actually begins with the much-maligned Starbucks. While the first location opened in 1971, the 1980s saw growing interest among the increasingly wealthy, connected, and cosmopolitan generation in high quality coffee. Rather than random bags of ground coffee thrown haphazardly into a percolator, market share was growing (up to 10% in 1989) of single-origin and single-estate coffee beans. Starbucks advertised itself on quality, buying green beans directly from the growers and roasting them in-house. They expanded rapidly even as coffee in general was losing market share in soft drinks, with dozens of locations opening up. By 1996 the first overseas Starbucks had opened in Japan.

Another important coffee retailer in this time period was The Coffee Connection of Boston. While Starbucks was selling dark roasts with rich and roasty flavors, The Coffee Connection specialized in light roasts that allowed the individual character of the beans to come out (having tested this myself, they have a point). During their aggressive expansion, Starbucks bought out The Coffee Connection in 1994. Why is this so important? Because one other beverage they had was the Frappuccino, a blended iced coffee drink.

The Frappuccino started Starbucks' long love affair with sweet iced coffee drinks. As people serious about their coffee got into drinking single-origin beans lightly roasted without any cream or sugar, the youth at large who weren't as interested now had coffee in a sweet, cold form that was easy to pick up from countless stores (or buy in bottled form as of 1996). The expansion of Starbucks turned coffee on its head, from a crappy cup of joe at the office to a sugary drink beloved by teens and college students. Marketing campaigns, rotating specialty drinks (especially the famed pumpkin spice), and free wifi created a juggernaut.

The "third wave" of coffee is a continuation of the single-origin side of things. Much like the craft cocktail revolution that came around the same time in the mid-to-late 2000s, there's been a heavy focus among coffee nerds on extreme quality. Specialty single-origin beans, light roasts that let you taste the full flavor of the terroir, and an emphasis on transparency (especially with concerns of child labor and even slave labor being used on coffee plantations). This is where I personally sit with coffee, as I've actually had the pleasure of going to extremely precise coffeehouses like Hi-Collar in New York City that let you buy unique single-origin beans and have them made exactly as you want.

At the same time, this period saw the commonality of single-cup brewers like the Keurig K-cup. People wanted good coffee, but didn't want the hassle of brewing a whole pot or hitting up Starbucks on the way to work. Devices like the K-cup precisely brew a single cup with extremely little effort, not even having to measure grounds to get a consistent product. The obvious downside, of course, is the massive waste of these products.