Wave in coffee world primarily mean a coffee consumer movement.
First Wave (1960's) - coffee to consume
Image: A 1966 print ad of Nescafe Instant coffee powder
1. Coffee grew amongst the masses and the general consumer was able to access coffee at home, office (and in case of India, at Indian coffee houses in the metros).
2. The use of instant coffee powder became popular.
3. The taste of first wave coffee was weak and acidic. It was quantity over quality so adding tons of cream (or milk) and sugar was the norm to make up for the taste.
Second Wave (1970's – 80's) - coffee to enjoy
Image: No. 1912 Pike Place, Seattle - the second location of the ‘original' Starbucks cafe established in 1971. (Image source: The Guardian)
1. Peet’s coffee & Starbucks brought higher quality coffees and espresso based drinks such as the Frappuccino to the masses in USA.
2. Running coffee shops became big business in USA and Europe.
3. Dark roasts were the highlight of second wave movement and espresso became everyday coffee drinks. People started learning about coffee beans & how it’s brewed.
Meanwhile, in India ...
India through the 70's and 80's was behind an iron curtain and remained completely isolated from this second wave movement throughout the period.
It is not known exactly when but some creative individual in North India during this time concocted a steam machine and used it to steam milk mixed with sugar and instant coffee powder and fooled an entire generation of Indians by calling the resultant beverage an espresso!
Image: Espresso? I think not!
Third Wave* (90's/2000’s – present day) - coffee to appreciate
1. Coffee drinkers became interested in the character of coffee: where it’s from, how it’s created, who trades it, who roasts it and how it’s brewed.
2. Espresso making hardware adapted to newer, lighter roasts of coffee with precision grinders, PID controllers and many other dosing tools & techniques. Hand drip coffee methods with carefully chosen tools such as pour over kits, siphon, Aeropress became popular.
3. High quality beans (aka specialty coffee) and light roasts from specific farms with high quality processing & roasting techniques became highlights of third wave coffee. People started appreciating coffee like wine & craft beer.
In India we were still playing catch up on second wave movement in the 90's and the first nationwide second wave retail chain was Cafe Coffee Day, setup in 1996. This was soon followed by home grown chain Barista and then the international retail chains such as Coffee Bean & Tea Leaf and Costa Coffee etc. In a glaring omission, the global second wave giant Starbucks was a late entrant to second wave party in India and only setup shop in 2012!
The third wave movement started in 2010 decade in India and is progressing at a much better pace than the blackout periods of the 80'. Specialty coffee is rapidly gaining popularity in metros and tier 2 cities, supported by growing popularity of e-commerce players like Amazon.
Third wave has been a movement where coffee drinkers learn to pay more attention to and respect the style of coffee rather than just seeing it as a liquid to put in their mouths.
*The term third wave was coined by Trish Rothgreb of Wrecking Ball Roasters in USA.
References/Further reading: Craft Beverage Jobs , The Bean Vagrant , Wikipedia , Eater , ILoveCoffee.jp