The Good, The Bad and The Ugly.
An ounce of an espresso shot can make a whole lot of difference in your drink.
The Good
Good espresso has 3 layers if you look at it properly. Usually the bottom of the espresso is darker than its a dark brown body and topped with rich golden crema. It is usually extracted within 22 seconds. The timing’s just my recommendation. Other baristas prefer 22, 21 or 23 seconds. However, timing is just one of the criteria for good espresso. Other conditions that has to be taken into account is the pump pressure, machine pressure, oxidation of espresso ground/beans and the loss of temperature.
The Bad 
Bad espresso is usually extracted after 26-27 seconds and it tastes horrible. You could tell a bad espresso from its distinct black body.
The Ugly
The ugly side to espresso is a shot that is extracted too fast due to wrong method of tamping or the wrong amount of pump pressure. You can tell an ‘undershot’ (less than 20 seconds extraction time) espresso by its reddish brown body.
Filed under: The Barista Coffee Times | 3 Comments
Shikin, I never knew that there’s so much to know about cappuchino…
FYI, I’m a diehard coffee drinker
I’ve heard (even from a local barista’s) that the 25 second rule is a myth, and has much more to do with the other conditions you listed… Non the less, great post! I’m relatively new to learning about espresso… I bought a Rancilio machine and grinder just about a year ago… but I’ve been absolutely enthralled with everything to do with learning! I have recently started attending a monthly tasting night at a local coffee shop that buys, roasts, and exports coffee to Seattle! Incredible stuff! I look forward to reading your posts!
I find that the characteristics of the pour offer the best signs of shot quality. A perfect shot does indeed finish in 20-25 seconds, but a slightly underextracted or overextracted shot can be “saved” by varying this time according to the characteristics of the flow.
A perfect shot always has a “double mousetail” of extremely thin (less than 1/8″) espresso flowing from the portafilter for the duration of the shot. If this stream widens or pales, the shot is spent and bitterness is flowing into the cup. Conversely, if only a few drops come out and large oil bubbles form, the puck is packed too tightly and grounds are too fine, resulting in an extremely sour shot with little to no crema.
Differences in ambient air temperature, barometric pressure, humidity, and the nature of the beans themselves (is it a blend or a single-origin, wet-process or dry-process or some combination thereof, roasted into second crack?) can all make it difficult or even impossible to pull drinkable shots, even if exceptional equipment is being used. Using coffee beans that are a day fresh out of the roaster results in fizzy, nasty, sour, acrid espresso. Use beans that are a month old and the espresso will be flat and dull.
Timing is highly dependent on these other variables. A single-origin dry process espresso roasted just to second crack, ground to a fine degree, and updosed will produce a beautiful ristretto that might take 30-35 seconds to fully pour. Conversely a French-roasted Southern Italy wet-process bean might pull in just 18-20 seconds. If your barometric pressure drops dramatically and you’re using a HX machine, be prepared for perpetually awful shots as the boiling point and pressure calibration get completely messed up, resulting in sour low-temp bubbly extraction. Not giving beans time to depressurize after they’ve been stored in a sealed jar or tin container (a la Illy) will result in fizzy sourness as well.