Forcing water at nine bars of pressure through hard packed fresh ground coffee produces what the Italians call "crema". Impossible to define, it has been described as a polyphasic colloidal foam. Polyphasic means changing states, going through phases. With over a thousand aromatic compounds continuously breaking down and combining and a foam structure that is releasing its gas and aromas with each passing second, espresso is a perfect cuisine to have developed in the second half of the 20th Century. It is a superb example of chaos. You can guess at what it is by determining its chemistry relative to an exact time after brewing-but by the time you have picked up your pencil it is something else. Espresso is a culinary chimera.Schomer's Table@Lucidcafé 16
Here David Schomer romanticises the espresso crema beautifully, delicately relating it to science and at the same time drawing images of the narrow, chaotic backstreets of Italy, mopeds buzzing as they carry their un-helmeted occupants from their first espresso of the day onwards to appointments, dates and the next espresso.
The crema can be seen as the face of the espresso: at a glance, the maitre barrister can tell if the espresso has been under- or over-extracted, and from this remedy the problem.
Crema Colour: |
Cause: |
Possible actions to take: |
| More white than brown | Under-extraction (the water is not in contact with the coffee for long enough) |
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| Burnt, or perhaps appearing too dark in the center | Over-extraction (the water is in contact with the coffee for too long) |
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