1:3 — Gettin' high, protect the vulnerable, and under pressure!
Edition No. 14
1 Fun Thing
The next time you call yourself an adrenaline junkie, remember this 1960s mom.
The Western Ghats, where a lot of Indian coffee grows, are a biodiversity hotspot and home to at least 325 globally threatened species. Some of the most at risk are the lion-tailed macaque, Asian elephant, and tiger, all of which are endangered and the gaur (Indian bison) which is vulnerable.
When brewing espresso, the rate at which water flows through the puck of coffee expectedly increases as the pressure rises. Fascinatingly, when the pressure exceeds 10 bars, the flow rate drops significantly, and is why very high pressures are avoided. Termed “secondary puck compression” by Decent Espresso’s John Buckman, it is speculated that this may be due to the cellulose of coffee particles deforming and blocking any remaining pores.
So, what exactly is the gorgeous golden brown, mottled foam on espresso that we refer to as crema? CO2 trapped in beans during roasting is forced into solution by coming in contact with hot water at high pressures. Upon exiting the portafilter basket, the espresso is no longer under pressure. The CO2 comes out of solution as bubbles that are stabilised by surfactants present in the coffee, creating crema.