Palouse Coffee Club
What is crema?
Crema is the layer of dense, light brown foam on top of a shot of espresso. It forms when water under high pressure picks up carbon dioxide left in the ground coffee from roasting, and coffee oils emulsify into tiny droplets. Drip, French press and pour over do not make it.
What makes crema
Roasting creates carbon dioxide inside the bean. When an espresso machine pushes water through the coffee at high pressure, Wikipedia's espresso article explains, that water dissolves more of the gas than it could at normal pressure. As the shot leaves the basket and the pressure drops, the gas comes out as fine bubbles. At the same time, oils from the grounds are emulsified into a colloid, a mix that does not happen in other brewing methods. Gas bubbles and oil droplets together make the foam.
The pressure involved is serious. Wikipedia's coffee preparation article gives espresso brewing as water at 91 to 95 °C forced through the coffee at 8 to 18 bar.
Why the age of the beans matters
Crema depends on carbon dioxide from roasting, and roasted coffee keeps giving that gas off for days after it leaves the roaster. That is why roasters use bags with one-way valves, or let coffee rest before vacuum packing it. It also means beans that are weeks old have less gas left to give a shot, and so less to build crema with.
This is one place where buying from a nearby roaster helps in a way you can see. Several Washington roasters we list roast to order: Olympia Coffee Roasting roasts every coffee to order each day at its downtown Olympia roastery, and Espresso Vivace says its whole bean orders ship the day they are roasted, checked September 27, 2026. A bag mailed within Washington has a short trip to make. Why local roasters matter has the rest of that case.
Crema, microfoam and bloom compared
Three different foams turn up in coffee, and people mix up the names.
| Foam | Where you see it | What it is |
|---|---|---|
| Crema | On top of an espresso shot | Carbon dioxide bubbles and emulsified coffee oils, made under pressure |
| Microfoam | In a latte or flat white | Steamed milk with tiny, even bubbles, made with a steam wand |
| Bloom | At the start of a pour over | Carbon dioxide bubbling out when hot water first wets fresh grounds |
Microfoam is what baristas pour into crema to draw latte art. Seattle has a claim there: Espresso Vivace founder David Schomer is credited with developing and popularizing latte art in the United States.
Where the word comes from
Crema is Italian for cream. Early steam espresso machines, sold from 1905, could not make it; their shots came out black and bitter. Achille Gaggia's lever machines, sold from 1948, pushed water through the coffee with a spring-loaded piston at up to 12 atmospheres and produced the foam. Gaggia advertised the drink as crema caffè, cream coffee, and that was the first name of modern espresso before the word espresso took over.
Crema also shapes how espresso drinks are built. A long black is made by pouring a shot into hot water rather than the other way round, which keeps the crema intact; an americano pours the water onto the shot.
Beans for a good crema, from the club
Pick the Espresso-friendly style in the plan builder and choose whole bean, so you grind right before each shot. Every box is roasted to order by a different independent Washington State roaster, with the promise "Roasted and shipped within 3 days." $16.99 a bag; first bag free, you pay $7.99 shipping.
Related terms and sources
Related: espresso, ristretto, espresso roast, microfoam, bloom, long black, degassing.
- Wikipedia: Espresso (what crema is, Gaggia's machines)
- Wikipedia: Caffè crema (the 1948 name)
- Wikipedia: Coffee preparation (espresso temperature and pressure)
- Wikipedia: Coffee roasting (carbon dioxide after roasting, valve bags)
- Wikipedia: Microfoam and Wikipedia: Long black