Crema (espresso)
As Crema is called the dense golden brown foam on espresso forms. The crema consists of coffee bean oil , proteins , types of sugar and carbon dioxide and binds a large part of the espresso aroma. When using Robusta coffee, more crema forms than when using Arabica coffee, which is usually superior in taste . Therefore espresso coffee blends are often created with a share of at least ten percent of the cheaper Robusta beans. In addition, coffee must be ground very finely for preparation in espresso machines so that a fine crema forms.
The crema allows conclusions to be drawn about the preparation and the freshness of the roast based on the amount, color, density and its standing time, but only when comparing similar mixtures. The older the coffee, the less crema, as aging coffee loses the crema-forming CO 2 . Coffee that is brewed too hot usually has hardly any crema, which is then dark brown and torn. Espresso that is brewed too quickly, too cold or too thinly has a sand-colored crema.
Inexpensive espresso machines, most fully automatic coffee machines and most machines that work with coffee pods artificially produce crema via a valve, which does not allow any conclusions to be drawn about the roasting and preparation. This foam has little in common with the taste of real crema, but is still often touted as an essential feature of such machines. This artificially created crema consists of coffee that has been frothed with air, which means that it cannot be tasted separately. You can recognize them by their coarse vesicular structure. The bubbles of real crema can hardly be seen with the naked eye. A teaspoon of granulated sugar placed on the not yet stirred espresso stays on top for three to five seconds with real crema. Because of the high content of palmitic acid in coffee oils, real crema solidifies at a temperature of 3 to 11 ° C. Real crema does not form directly when the espresso runs out of the machine, but rises out of the espresso in the seconds afterwards.
possible sources of error
| Crema (foam) | |||
|---|---|---|---|
| error | Possible Cause | ||
| Not enough crema | Beans ground too finely, coffee too old, not enough coffee used, cup or machine dirty | ||
| Crema too dark | Beans ground too finely or roasted too much, too much coffee used, brewing temperature too high, pressure of the coffee in the portafilter too high | ||
| Crema too light | Beans too old or ground too coarsely, brewing temperature too low | ||
| Crema does not have a stand | Cup cold or too hot, water pressure too low | ||
Web links
Individual evidence
- ↑ Cornelia Schinharl: Italy - Kitchen and Culture, Verlag Graefe and Unzer, page 79 partially accessible from Google Books .
- ^ S. Krist, G. Buchbauer and C. Klausberger: Lexicon of vegetable fats and oils . Springer Verlag , Vienna 2008, ISBN 978-3-211-75606-5 , p. 184-187 .
- ↑ What is Crema? . Retrieved June 21, 2015.
- ↑ Susan Zimmer: I love coffee, Over 100 Easy and Delicious Coffee Drinks . Andrews McMeel Publishing, 2007, ISBN 978-0-7407-6377-9 , pp. 51 (English, limited preview in Google Book Search).