How to Make Espresso
espresso should be extraordinarily sweet, have a potent aroma, and
flavor similar to freshly ground coffee. The cream would be dark
reddish-brown. It would be smooth, yet thick. A perfect espresso
would be enjoyable straight with no additives, yet bold enough to not
disappear in milk. A pleasant and aromatic aftertaste would linger on
the palate for several minutes after consumption.
Now I will discuss the various factors and
problems with espresso that limit its potential and describe how you
can maximize the espresso potential. If any of these factors are off
the espresso potential will be limited.
- Without a good espresso blend you cannot have a good espresso.
Coffees must be blended to achieve the sweetness, aromatics, and
smoothness desired in espresso. The blend must also be fresh. We
recommend using espresso within four days of roasting. Order some excellent espresso blends from Neighbors Coffee.
- Too often you will find espresso roasted very dark. This results in
a bitter, charcoal tasting brew. People that know how to blend
espresso will roast light to preserve the aroma and sugars. More information.
- The grind must be continuously monitored throughout the day to
achieve an extraction time of 25-30 seconds. Do not change the
pressure you tamp with to compensate for a grind that has become too
large or small. More information on grinding.
- A high quality burr grinder is essential for espresso. A conical
burr grinder is preferred to flat burrs since the particle size is more
even, they last longer, and the coffee is not heated during the
grinding process. If the burrs become hot the aroma of the coffee will
be diminished. A conical/parallel hybrid blade is considered the best
design by many coffee professionals.
- Dosing -
Coffee must be freshly ground to achieve peak flavors. Grind and dose
on demand. When someone orders an espresso grind only what is
necessary for one shot, dose properly, tamp, and brew. Discard any
espresso grounds that are not used within 30 seconds.
- Distribution - Distribute the coffee evenly after dosing in the porta-filter before tamping. More information.
- Tamping -
Tamp the coffee once very evenly with 5 lbs of pressure, then once with
30 lbs of pressure, and polish 720° with 20 lbs of pressure. More information.
- Water mineral content
- The water used for espresso must be filtered. Some cities must even
compensate for the mineral content of their water. Over time oxygen
will be forced out of the water in the espresso machine leading to off
tasting water. Try filling a small glass with water, letting it cool,
and tasting it for off flavors. If the water tastes strange you may
want to dump the tanks daily and begin with fresh water.
- Water temperature
- The water temperature should be stable and somewhere between
92-96°C. The choice of the espresso machine is very important to both
water temperature and temperature stability.
- Temperature stabilizing - A stable temperature means consistent espresso.
- Water pressure
- The pressure of the water forced through the espresso should be
between 9 and 10 atm. This pressure is responsible for the development
of the cream.
- Boiler pressure -
The boiler pressure determines the amount of water to be incorporated
in the steam. If your milk is not foaming correctly as described in milk texturing
you may want to experiment with different boiler pressures, but this
should only be altered by professionals. You can check your boiler
pressure by looking at the boiler pressure gauge on the front of most
- Extraction time
- Extraction time to fill two 1-oz cups should be between 25-30
seconds. Despite the time the pump should be turned off if the
espresso becomes slightly lighter in color. The goal is to have a dark
red espresso take approximately 25-30 seconds to brew with no change in
- Porta-filter and basket - The
porta-filter should always remain the same temperature as the water
used to brew the espresso. Therefore it should always remain in the
group head. The basket should hold 16-18 grams of coffee and must be
straight walled. Curvatures in the basket will lead to uneven
- Timeliness - Act
quickly, but carefully. You should spend no longer than 30 seconds for
the time it takes to dose, distribute, tamp, pre-heat, and brew the
- Espresso machine cleanliness
- This is probably the biggest problem with espresso today. If the
machine, basket, and porta-filter are not cleaned regularly the
espresso will always taste rancid.
- Espresso grinder maintenance
- Everyday the burr blades should be swept clean. Between shots you
may want to brush out the excess espresso that gets stuck between the
burrs and the dosing chamber. The burrs must be replaced at least
yearly so that they continue to produce coffee granules with a maximal
- Environmental Factors -
The humidity and temperature will change throughout the day. Since
coffee is hydroscopic (absorbs moisture), the grind size must be
changed throughout the day to achieve a brew time of 25-30 seconds.
The temperature will not affect the espresso like the humidity, but it
is important to avoid exposing the coffee to any high temperatures
- Espresso cup - The
espresso cup should be pre-heated from a source other than the espresso
machine. Filling a cup with water from the espresso machine prior to
brewing the espresso will lower the temperature of the water in the
boiler and the espresso extraction will be uneven. The espresso cup
should have thick walls and a narrow mouth to retain heat and aroma,
- Practice - I cannot
overstress the importance of practicing and experimenting. The key to
espresso is to realize that it always has further potential. By
changing any one of these factors you can improve or diminish its
potential. Espresso preparation is an art that demands the precision
and dedication of science. I have never achieved, nor have ever seen a
perfect espresso. A perfect espresso more of a concept than an
actuality. The beauty is that espresso is volatile and difficult. If
it were easy we would develop a machine that can brew a perfect
espresso every time. There are so many factors involved in espresso
preparation that only a human mind and a passionate heart can begin to
understand and control its complexity.