I’ve been asked several times why the espresso here tastes different than many other places. I’ll just write a bit about espresso here and cover that question next time. Espresso is the product of a method of brewing, in which hot water is forced under pressure (about 9 atmospheres) through tightly packed coffee. The key to brewing espresso is obtaining optimum extraction. An all too common mistake is overextraction. In general, the good stuff in the coffee extracts first. If one continues to extract (ie. continues to let water pass through the grounds) after most of the pleasant compounds have been extracted, that person is committing the sin of overextraction. By passing to much water through the grounds you end up with a thin, bitter, watery drink. The “ideal” extraction for espresso is to get one ounce of espresso from 7 grams of grounds. The time it takes the water to penetrate and flow through the grounds must also be considered because if it takes to long brew that rich, creamy, flavorful, one ounce shot, you would be overextracting on a time basis – as the water has been in contact with the grounds for to long. Vice a versa with underextraction. The “ideal” extractiong time for a shot is 25 seconds. Some like a shot pulled a little longer to mellow it a little (a lungo, or long shot) and some like the shot pulled shorter for a very small and intense shot (a ristretto, or short). Espresso originated and evolved in Italy thus much of the espresso jargon is Italian or relates to Italy. I’ll talk about the roast degree and bean blends with respect to espresso next time.