Fundamentals
for "Reaching Espresso Nirvana"
For Traditional (Handled), Semi-Automatic Espresso Machines
Note: The following does not fully apply to
superautomatic, hand lever, or steam power-generated espresso machines
that may operate under different principles and guidelines for proper
operation .
Part II: The "Science"
In this section, we will cover the following areas that pertain
to the "science" for Reaching Espresso Nirvana.
The
Fresh Roast Of The Coffee Bean
The most important ingredient to any espresso, cappuccino, or latte
is the coffee bean and its degree of roast. As you are no doubt
well aware, there are many different types of coffee beans originating
From many different countries, with roast masters applying their
own degree of roasting techniques and roast times. Coffee beans
from a single farm are known as "Estate Coffees". Coffee
beans from a single country are known as varietals. Blending, as
preferred by roast masters, is the mixture of 2 or more "Estate
Coffees" and/or varietals to produce their own signature coffee
blend. Each Estate Coffee, Varietal, and Blend would change in flavor
characteristics when the degree of roast changes. Just as wine changes
flavor with age, coffee beans change in flavor with different roasting
times.
According to roasting professionals, there are four (4) different
types of roasts that are suitable for proper espresso extraction.
In order of increasing darkness, they are Full City Roast, Vienna
Roast, Espresso Roast, and French Roast. The main reason to utilize
coffee beans with these roasts is that the flavor and crema production
of espresso is highly dependent upon the oils formulated within
the coffee beans during and after the roast. Any roast lighter than
Full City Roast may not properly caramelize the coffee beans to
produce enough oils for your espresso. As the roasts become darker,
the oils tend to move to the surface of the coffee beans and you
will see a "glossy" surface or feel the oils on them.
Another important factor in the roasted bean is freshness. Freshly
roasted beans will provide superior tastes and aromatics. Stale
beans or those laying around for a while will not allow you to achieve
the fundamentals for Espresso Nirvana no matter how much you master
the other variables.
Ultimately, it is important to experiment with different coffee
beans (Estate Coffees, Varietals, and Blends) with a varying degree
of roasts to find the one that best suits your palette! Most importantly,
it is ideal to use coffee beans within 7 days of the roasting date!
The Fineness of The
Coffee Grind
One of the most important parameters to proper espresso extraction
is your coffee grind.
Fineness Of The Coffee Grind
The most important aspect of grind fineness is the ability to grind
very, very fine (like NutraSweet) AND consistency. The consistency
of the grind is directly attributable to the design and performance
of your grinder. There are three types of grinders - hand grinders,
blade grinders, and burr grinders.
Hand Grinders
Some, but not all hand grinders can grind fine and consistently
enough for espresso extraction. The process of hand grinding involves
the laborious task of turning the grinding handle many times. The
advantage is that this slow process of grinding does NOT produce
any heat that would negatively affect your coffee grind.
Blade Grinders
Blade grinders are identified by a whirling blade that "chops"
the coffee beans. Grinding long enough, the coffee beans will result
in a coarse grind more suitable for drip coffee. Grinding even longer,
the coffee beans sometimes can turn slightly finer. However, the
finest grind is not suitable for proper espresso extraction. The
reasons are 1) The coffee grind will not be consistent, and 2) The
high speed blade will create excess heat which will adversely affect
the oils in the grind.
Burr Grinders
Burr grinders typically consist of two opposing grinding burrs -
one stationary and one attached to the motor wheel. There are two
types of burrs - conical and flat. Conical burrs are designed to
produce greater consistency in the grind fineness. However, the
type of burr becomes irrelevant as one chooses a high quality "flat"
burr grinder that typically houses larger burrs closer to the commercial
type.
Burr grinders typically have the advantage of lower heat generation
due to the lower speed of the burrs. In addition, different degrees
of fineness are achieved by changing the setting of the distance
between the grinding burrs. The greater the distance between the
grinding burrs, the coarser the grind. Oppositely true, the lesser
the distance between the grinding burrs, the finer the grind. The
equidistance of the grinding burrs achieves the consistency needed
for proper extraction of espresso.
The settings on burr grinders will differ from customer to customer
as all electric burr grinders have relative settings. This means
that a setting of "6" on one particular grinder will not
be precisely the same as a setting of "6" on another unit
of the same model grinder.
Second, each type of coffee and the darkness of roast will require
different settings to adhere to the fundamental rule. In the former
instance, beans from two different farms, countries, or blends will
have differences in the grind fineness from one to the other in
acquiring the fundamental rule. The reason is that different beans
have varying degrees of hardness. In the latter instance, a darker
roast will require a coarser grind when compared to a medium roast
to achieve similar extraction times and volume (however, the taste
will be different). lighter roasted espresso beans should be ground
finer than darker roasts. The main reason a finer grind is required
on lighter roasts is that lighter roasted coffees do not have the
oils on the bean surface. Therefore, a finer grind is needed to
expose those oils on a greater surface area. Darker roasted coffees
tend to have more oils at the surface.
Therefore, experimentation (not frustration) is essential in locating
the best grinder setting for your coffee beans.
Finally, burr grinders should always be adjusted
when the grinding burrs are in motion. This is especially important
when adjusting from a coarse setting to a finer setting. The reason
is that coffee grinds will always be between the two burrs, and
this will not allow you to properly adjust the grinder to a finer
setting. The end result is a more consistent grind and less chance
of the burrs becoming dull or gummed.
Dosage
The amount of coffee (known as the dosage) you place
into the filter basket (on traditional filter handle machines) will
also affect the "Fundamental Rule". The industry standard
in the United States is 7 grams of coffee roasted and ground for
the single espresso shot and 14 Grams of coffee roasted and ground
for the double espresso shot. This standard is an industry guideline.
This means that the guideline can be adapted and changed to one's
personal need to achieve the crema rule and taste profile desired.
Typically, adding an amount greater than 7 grams of coffee will
result in a longer extraction time since the extra coffee will increase
the path the water needs to travel and creates greater resistance.
Less than 7 grams would result in a quicker extraction time since
there will be less coffee to create the resistance needed for a
proper extraction.
Wet Pucks: Wet pucks can result from too little coffee in the filter
basket in combination with too fine a grind. When a wet puck is
noticed, you may need to add mroe coffee to the basket and coarsen
the grind. Please note the flavor profile may change as a result.
If the best flavor profile is achieved with the result being a wet
puck, then it is a good idea to leave things alone.
Tamp Pressure
Tamping is essential for proper espresso extraction. Tamping results
in enough resistance for the water to pass through the grind, creating
even distribution of pressure, and aids in allowing easy removal
of the coffee from the basket after extraction.
Tamping is the application of force to compress the loose coffee
grind in your filter basket into a "puck". A special tool
known as the "tamper" is utilized to press down on the
coffee. A tamper is pre-built into some machines. In others, the
back of the measuring spoon works as a tamper. More commonly though,
a tamper must be purchased seperately.
The tamper consists of a tamping plate or "base" (made
from plastic, wood, aluminum, or stainless steel), a stem, and a
handle. There are two types of tamper bases - flat or curved. Flat
tampers are typically used when the filter basket is straight on
the bottom of the basket and curved tampers are used when the filter
basket has a curved bottom. Neither type is universally superior
to the other in terms of performance. Technique is more important
than type for achieving a good tamp.
There are two types of home model espresso machines that impact
the technique needed for proper tamping pressure. The first type
are home model espresso machines that have PRESSURIZED handles or
filter baskets. Please note that either the basket or the handle
may be pressurized but never both on the same machine. This design
compensates for tamping error by allowing the filter handle basket
to create the pressure needed for proper extraction of espresso.
Machines of this type include Capresso, Saeco, and the Solis Crema
SL. Other machines, such as Gaggia, sometimes include pressurized
disks that serve the same purpose. The second type are machines
that have standard, non-pressurized filter handles or baskets. All
traditional, commercial machines, as well as many home models, are
of this type. Tamping pressure is much more critical on these machines
since the resistance relies more on tamping pressure and grind fineness.
This is due to the absence of added pressure from the design of
the basket or handle. Below are the techniques for machines with
pressurized and non-pressurized filters and baskets.
General Technique For PRESSURIZED Filter Handles and Baskets
The general technique for tamping in a pressurized filter handle
or pressurized filter basket would be less than 30 pounds. In other
words, only a very light tamp is needed. The Proper Tamp Can Be
Accomplished With The Hand Tamper, With The Tamper Built Into The
espresso Machine Or Grinder, Or With The Back Of The Measuring Spoon.
Please Note That To Firm Of A Tamp Will Not Allow The Water To Come
Through The Coffee Grind Or Will Result In A Very Long Extraction
Time (Usually Exceeding 27 Seconds)
General Technique For STANDARD Filter Handles and Baskets
The General Technique For Tamping In A Standard Filter Handle Is
To Apply About 30-50 Pounds of Evenly Distributed Pressure Into
The Coffee Ground Dosed Into The Filter Basket. The Technique Should
Be Completed With A Slight Twist To Result In A Slightly Polished
Finish On The Surface Of The Tamped Coffee. The 30 Pounds Of Tamp
Pressure Is A Guideline And An Area for Experimentation As Some
Of Our Customers Have Used Less Tamping Pressure and Others Have
Tamped To 50 Pounds of Pressure. Some 1st-Cup Coffee Company Customers
Have Used A Bathroom Scale To Measure Tamp Pressure. By Using A
Scale To Measure Pressure, You Can Change One Of The Other Parameters
To Achieve The Fundamental Rule.
Brewing Temperature
The Optimal Brewing Temperature, As Measured At The Point Where
The Water Contacts The Coffee Grind, Is 190-204 Degrees Fahrenheit.
The Temperature of The Extracted espresso Will Vary From 150 Degrees
Fahrenheit to 180 Degrees Fahrenheit The temperature Loss Is Attributable
to the Ambient Temperature, The Brew Group Temperature, and The
Temperature of The Cup.
Therefore, It Is Important To Preheat The Brew Group and The Cup
Prior To Extracting Espresso The Brew Group Can Be Pre-Heated By
Pulling An "Empty Shot". In Other Words, The Filter Handle
and Basket Should Be Placed On The Brew Group (or Grouphead) Without
Any Coffee and Hot Water From The Machine Should Be Run Through
and Into The Cup That Needs To Be Pre-Heated. We Have Found A Temperature
Loss of Up To 100 Degrees Fahrenheit In Circumstances Where Customers
Do Not Preheat The Brew Group, The Filter Handle, The Filter Basket,
or The Cup. Also, Do Not make The Mistake of Rinsing Your Filter
Handle and Filter Baskets With Cold or Hot Faucet Water. This Can
Also Reduce The Temperature. It Is Best To Wipe The Handle and Basket
Clean With A Cloth or Paper Towel.
In Addition, The Closer The Spouts of The Filter Handle To The
Base Of The Cup, The Less The Temperature Loss Due To Room Temperature.
Brewing Pressure
The Optimal Brewing Pressure For Pump-Driven Espresso Machine is
8 to 9 Bar or atmospheres. Most Machines Show Pressure "Ratings"
of Greater Than 9 Bar. Please Note That These "Ratings"
Indicate The "Maximum" Pressure That Can Be Produced By
The Pump. It Does Not Mean Better Espresso! Quite The Contrary!
Over 9 Bar Pressure Can Produce Very BITTER Tasting Espresso
Since Most Home Model Machines Do NOT Have Gauges To Monitor The
Brewing Pressure, You May Wonder How You If We Are At The Optimal
Pressure. The Answer Is Very Simple. We Will Know If We Are At The
Right Pressure By Comparing Our Results to The Fundamental Rule
- Double Espresso Shot = 2 to 3.0 Fluid Ounces in 23 to 27 Seconds
The Pump Pressure Is Regulated By The Resistance In The Filter
Basket - The Resistance of the Espresso Bean Finely Ground And Tampered
Into The Filter Basket Or The Resistance Created By The Pressurized
Filter Handle or Basket.
A Greater Resistance in The Filter Basket Will Result In A Greater
Pressure Created By The Pump. Too Much Pressure, The Espresso Will
Take Longer Than 27 Seconds To Extract. This Is Called over extraction
And Will Result In A Very Bitter Flavor. In Addition, The Home Model
Espresso Machines We Sell Have An Expansion Relief Valve - When
There Is Too Much Pressure (That Over 11-12 Bar), This Expansion
Relief Valve Will Open To Relieve The Excess Water Pressure And
Divert It To Either The Machine's Drip Tray or Back To The Water
Tank. The Purposes Are To Avoid Pump Damage and Lessen The Chances
of over extraction.
A Lesser resistance in The Filter Basket Will Result In A Lesser
Pressure Created By The Pump. Too Little Pressure, The Espresso
Will Take Less Than 23 Seconds To Extract. This Is Called under
extraction And Will Result In A Very Weak, Water Down Coffee. In
This Case, The Resistance In The Coffee Puck Needs To Be Increased
By Changing One of The Above Variables - Coffee Grind Fineness,
Amount of Coffee Grind, or Tamping Pressure. By Grinding Finer,
Increasing The Amount of Coffee Grind, AND/OR Increasing The Tamping
Pressure, The Resistance Will Become Greater To Extract At the Right
Pressure.
Therefore, The Resultant Brewing Pressure Is A Direct Result of
the Resistance In The Filter Basket. Now, That We Have Covered The
Science, We Should Morph Your Knowledge Into The Arte!
Copyright 2001. All Rights
Reserved. 1st-Cup Coffee Company, LLC
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