Thin, grassy, acidic espresso is a sign of 'third wave' coffee... the idea that you could roast the beans juuust enough to convert the sugars and keep a bunch o

Thin, grassy, acidic espresso is a sign of 'third wave' coffee... the idea that you could roast the beans juuust enough to convert the sugars and keep a bunch of neat flavors in a mild and bright cup. But they walk the line of juuust enough roasting very close, which often results in under roasting especially in copy cat producers. Underroasted coffee is marginally ok in pour over / chemex, but is horrible in espresso. There is a 'fourth wave' coffee pushing back on this trend that anchors more to big dark espressos sometimes even using robusta beans for extra creama and caffeine.