Zach And Dani's Coffee roaster Instructional Manual - page 8
Nothing Influences the Taste of Coffee
More Than Roasting
Nothing influences the taste of coffee more than roasting. The same unroasted
coffee can be roasted to taste baked, sour, bright and dry, full-bodied and mellow,
rounded and bittersweet, or even charred. In appearance, roasted beans can range
from light brown with a dry surface through dark brown with an increasingly oily
surface to black with an almost greasy look.
It all depends on when you stop the roast - how “done” you allow the coffee to
become before you start the cooling cycle. The best way to understand how degree
of roast affects taste is to experiment - take the same unroasted coffee and bring it
to four or five progressively darker degrees of roast, taste them all, and see which
one you like best.
However, here are a few popular names for coffees brought to varying degrees
of roast, together with descriptions of their characteristics. Keep in mind that these
terms are vague and overlapping; one roaster’s medium roast may be as dark as
another one’s espresso.
Generally, unroasted coffees taste most like themselves at lighter degrees of
roast. In other words, a Kenya will taste most like a Kenya at a Light through a
Viennese roast, a little less like Kenya at an Espresso Roast, and pretty much like
any other coffee at a Dark French roast.
Roast Styles and Flavors
Zach & Dani’s™ Instructional Guide and Roasting Journal
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• Bragging rights. So there you are, roasting a blend of Guatemalan
Huehuetenango and Sumatran Lintong, your kitchen pungent with smelly yet
glamorous smoke, when your friends arrive for dinner carrying that pathetic
bag of week-old house blend...
• Romance. Roasting your own coffee carries you deeper into the drama and
romance of coffee. That romance is nowhere as vividly encapsulated as in that
moment when a pile of hard, almost odorless grey-green seeds is suddenly
and magically transformed into the fragrant vehicle of our dreams, reveries,
and conversation. To ourselves be the magicians, waving the wand of
transformation, makes that metamorphosis all the more stirring and resonant.
What Does Roasting Do to Coffee?
Roasting…
1. Forces water out of the bean;
2. Dries out and expands the bean’s woody parts, making them more porous and
reducing its total weight of the bean by 14% to 20%
3. Sets off a continuous transformation of some sugars into CO2 gas, a process
that continues after the coffee is roasted and only concludes when the coffee is
definitively stale
4. Drives off some volatile substances, including a small part of the caffeine; and
finally and most importantly...
5. Caramelizes a portion of the bean’s sugars and transforms some into what are
popularly called the coffee’s flavor oils: the fragile yet deliciously heady mix of
complex substances that give coffee its aroma and a good deal of its flavor. It is
the caramelized sugars and flavor oils that (along with the approximately 1%
caffeine) give coffee drinkers the experience they crave.
After roasting, the bean is reduced to a protective package for the caramelized
sugars and flavor oils, which are secreted in tiny pockets throughout the bean’s
now woody, porous interior (or in very dark roasts, partly forced to the surface of
the bean, giving these roasts their characteristic ‘oily’ appearance). The CO2 gas
gradually works its way out of the bean in a process called degassing, which
temporarily protects the flavor oils from the penetration of oxygen and staling. Of
course, when the CO2 is finally gone, so is flavor. Vacuum cans, nitrogen flushed
bags, etc. are all artificial efforts to protect the coffee from the staling penetration
of oxygen.
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Zach & Dani’s™ Instructional Guide and Roasting Journal
New England or Light
Light brown; Dry surface; Tea-like and grainy
in flavor
American or Medium
Medium brown; Dry surface; Dry and brisk in
flavor
Viennese or Full City
Medium dark brown; Flecks of oil on surface;
Still dry in flavor but sweeter and rounder
French
Moderately dark brown; Light sheen of oil on
surface; Sweet, round flavor
Espresso
Dark brown; Surface can range from very oily
to barely slick; Round, roasty and rich in
flavor; Full body
Italian
Dark to blackish brown; Definite oily surface;
Sharply pungent and roasty but still sweet in
flavor
Dark French or Spanish
Very dark brown, almost black; Very oily;
Burned and bitter in flavor with a slight halo
of sweetness; Thin body