Fast roasted coffee providing increased brew strength and darker cup color with desirable brew acidity

Roast and ground or flaked coffee products which provide more brew strength and cup color at lower levels of brews solids. These coffee products contain darker fasted roasted coffee that is predominantly high acidity-type coffee that provide, when brewed appropriate conditions, a consumable coffee beverage having: PA1 (1) a brew solids level of from about 0.4 to about 0.6%; PA1 (2) a Titratable Acidity of at least about 1.52; PA1 (3) a brew absorbance of at least about 1.25, provided that when the Titratable Acidity is in the range of from about 1.52 to about 2.0, the brew absorbance is equal to or greater than the value defined by the equation: EQU 1.25+0.625.times.(2.0-TA)! where TA is the Titratable Acidity.

FIELD OF THE INVENTION 
This application relates to roast and ground and flaked coffee products 
that have been fast roasted. This application particularly relates to fast 
roasted coffees that provide a darker cup color and improved flavor 
strength, yet with a desirable level of brew acidity. 
BACKGROUND OF THE INVENTION 
Historically roast and ground coffee has been marketed on supermarket 
shelves by weight in 16-ounce cans. However, a recent trend in the coffee 
market has resulted in the demise of the 16-ounce weight standard. This 
trend emerged in 1988, when major coffee manufacturers began marketing 
13-ounce blends. The blends were prepared using "fast roast" technology 
that resulted in a lower density bean. Thirteen ounces of these lower 
density blends have nearly the same volume as the traditional 16-ounce 
blends. As a result they could be marketed in the old 1-pound cans and 
were priced about 20 cents below the previous 16-ounce list price because 
they used fewer beans. This down-weighting of coffee in cans has met with 
widespread acceptance in the industry. 
One process using fast roasting to lower bean density is disclosed in U.S. 
Pat. No. 5,160,757 (Kirkpatrick et al), issued Nov. 3, 1992. In the 
Kirkpatrick et al process, the green coffee beans are pre-dried to a 
moisture content of from about 0.5% to about 10% by weight, fast roasted 
to a Hunter L-color of from about 14 to about 25 and a Hunter 
.DELTA.L-color of less than about 1.2, and then ground, or ground and 
flaked. The resulting coffee product has a tamped bulk density of from 
about 0.28 to about 0.38 g/cc and is more uniformly roasted compared to 
traditional reduced density coffee beans. See abstract and column 2, lines 
35-45. 
Many recent "fast roast" coffees also have a higher yield of brew solids 
than previous 16-ounce coffees. These high yield fast roast and ground 
coffees exhibit improved extraction characteristics during brewing. Higher 
yield (sometimes referred to as higher mileage) coffees have typically 
been defined by the ability to extract more brew solids from the coffee 
beans so that an equivalent brew solids is achieved in the final brew but 
with less coffee used. In other words, these higher yield coffees can make 
more cups of coffee per ounce when compared to previous 16-ounce coffees. 
Fast roasting results in a puffed or somewhat popped bean. Fast roasting of 
coffee typically occurs in large multistage roasters (e.g., Probat, 
Thermalo, Jetzone, etc.) with very large heat inputs. These high heat 
inputs result in the rapid expansion of the roasted bean, but can also 
cause a high degree of bean roasting variation within the roaster. In 
addition, tipping and burning of the outer edges of the bean can be a 
major problem during fast roasting. 
One proposed solution for dealing with problems caused by fast roasting, 
including tipping and burning, is disclosed in U.S. Pat. No. 5,322,703 
(Jensen et at), issued Jun. 21, 1994. In the Jensen et al process, green 
coffee beans are dried prior to roasting to a moisture content of from 
about 0.5 to about 7%. These predried beans are then fast roasted to a 
Hunter L-color of from about 10 to about 16. These dried dark roasted 
coffee beans (about 1 to about 50%) are blended with non-dried roasted 
coffee beans (about 50 to about 99%), and then ground, or ground and 
flaked. See abstract and column 1, lines 50-63. 
The purpose in predrying according to the Kirkpatrick et al and Jensen et 
al processes is to make the moisture content of the resultant predried 
more uniform throughout. See column 3, lines 52-56 of Kirkpartrick et al. 
While predrying improves the flavor of all coffees, it particularly 
improves the flavor of lower grade coffees such as the Robustas. See 
column 8, lines 45-47. See also column 3, lines 13-15 of Jensen et al 
(dark roasting of non-dried coffee beans, especially low quality beans 
such as Robustas can result in excessive burnt-rubbery notes.) 
As alluded to in Jensen et al, a major problem with prior high yield 
coffees is their unbalanced flavor and lack of acidity. See column 1, 
lines 42-44 (enhancing extractability and brew coffee yield can be 
achieved but often at the expense of balanced flavor of the coffee brew). 
The Jensen et al process tried to improve this balance by blending the 
dark roasted pre-dried beans (providing strength with minimal 
burnt-rubbery flavor notes) with the lighter roasted non-dried coffees (to 
provide flavor and acidity). See column 1, line 64-68. This blending does 
result in higher acidity, but at the expense of diluting the high yield 
benefits of the pre-dried beans. 
Historically, coffee brew strength, as well as cup color, has been directly 
correlated to the level of brew solids present the brewed cup of coffee. 
To achieve increased brew strength and cup color, the coffee beans have 
previously been roasted faster, darker and with greater concentrations 
Robustas. Grinding the beans freer and flaking the ground beans thinner 
have also been used to increase brew strength and cup color. This often 
leads to undesired tipping and burning of the beans, along with harsh, 
rubbery notes (from the Robustas) in the brewed coffee. Coffee made this 
way also generally leads to a lack of desired acidity in the brewed 
coffee. 
Accordingly, it would be desirable to have a high yield roast and ground or 
flaked coffee product that provides a coffee beverage having: (1) a darker 
cup color; (2) increased brew strength; (3) yet with a desirable level of 
acidity 
DISCLOSURE OF THE INVENTION 
The present invention relates to a roast and ground or flaked coffee 
product which provides more brew strength and cup color, yet with a 
desirable level of brew acidity. This coffee product has a Hunter L-color 
of from about 13 to about 19 and comprises from about 50 to 100% high 
acidity-type coffee, from 0 to about 30% low acidity-type coffee, and from 
0 to about 50% moderate acidity-type coffee. This coffee product, when 
brewed under appropriate conditions, is capable of providing a consumable 
coffee beverage having: 
(1) a brew solids level of from about 0.4 to about 0.6%; 
(2) a Titratable Acidity of at least about 1.52; 
(3) a brew absorbance of at least about 1.25, provided that when the 
Titratable Acidity is in the range of from about 1.52 to about 2.0, said 
brew absorbance being equal to or greater than the value defined by the 
equation: 
EQU 1.25+0.625.times.(2.0-TA)! 
where TA is the Titratable Acidity. 
The present invention further relates to a process for preparing these 
roast and ground or flaked coffee products. This process comprises the 
steps of: 
(a) fast roasting green coffee beans comprising from about 50 to 100% high 
acidity-type coffee beans, from 0 to about 30% low acidity-type coffee 
beans and from 0 to about 50 moderate acidity-type coffee beans that have 
not been predried, or only partially predried, to a Hunter L-color of from 
about 13 to about 19 under conditions that prevent burning and tipping of 
the beans; 
(b) grinding the roasted coffee beans; 
(c) optionally flaking the ground coffee beans. 
Coffee products of the present invention perform across a wide range of 
brewers delivering a high quality beverage with desirable strength and cup 
color at a drastically reduced usage. These products are believed to have 
increased brew absorbance due to the formation (during fast roasting) and 
extraction of very large molecules (e.g., polysaccharides) from the 
coffee. What was previously unknown was how to make and extract these 
molecules using higher quality coffees and still maintain the desired 
higher acidity. What has been surprisingly discovered is that by careful 
fast roasting, even high quality washed Arabicas can be fast roasted to 
darker colors without burning. Careful fast roasting of these higher 
acidity-type Arabica beans produces the desired absorbance compounds, and 
sufficiently puffs the beans to allow extraction of these desired 
compounds. Subsequent mechanical disruption of the beans and cells 
(grinding and/or flaking) is also key in extracting these absorbance 
compounds to provide a consumable coffee beverage have the desired brew 
strength and cup color. 
DETAILED DESCRIPTION OF THE INVENTION 
A. Definitions 
As used herein, the term "density" means bulk density. Density or bulk 
density values herein can be measured by conventional means as tamped bulk 
density values. 
As used herein, "brew solids" refer to brew solids in a coffee brew 
obtained under standard brewing conditions (as described hereafter in the 
Analytical Methods section) using one ounce of a roasted and ground or 
flaked coffee product in a Bunn OL-35 automatic drip coffee maker with a 
water feed of 1860 ml at 195.degree. F. (90.degree. C.). 
As used herein, the term "1-pound coffee can" relates to a coffee container 
which has a volume of 1000 cc. Historically, one pound (16 oz.) of coffee 
was sold in this volume container. 
All particle screens referred to herein are based on the U.S. Standard 
Sieve Screen Series or on the average particle size in microns (.mu.m) as 
measured by Laser Diffraction on a Sympatec Rodos Helos laser particle 
size analyzer. 
As used herein, the term "comprising" means that the various coffees, other 
ingredients, or steps, can be conjointly employed in practicing the 
present invention. Accordingly, the term "comprising" encompasses the more 
restrictive terms "consisting essentially of" and "consisting of." 
All ratios and percentages herein are based on weight unless otherwise 
specified. 
B. Types and Grades of Coffee 
Coffee beans useful in the present invention can be either of a single type 
or grade of bean or can be formed from blends of various bean types or 
grades, and can be undecaffeinated or decaffeinated. In order to provide 
the desired acidity in the coffee beverage, the coffee beans useful in the 
present invention are predominantly high acidity-type beans in mounts of 
from about 50 to 100%, preferably from about 70 to 100% and most 
preferably from about 90 to 100%. As used herein, "high acidity-type 
beans" are defined as beans that deliver greater than about 1.9 Titratable 
Acidity. These high acidity-type beans are typically referred to as high 
grade coffees. Suitable high grade coffee having high acidity include 
Arabicas and Colombians characterized as having "excellent body," "acid," 
"fragrant," "aromatic" and occasionally "chocolatey." Examples of typical 
high quality coffees are "Milds" often referred to as high grade Arabicas, 
and include among others Colombians, Mexicans, and other washed Milds such 
as strictly hard bean Costa Rica, Kenyas A and B, and strictly hard bean 
Guatemalans. 
Coffees useful in the present invention can also include from 0 to about 
50%, preferably from 0 to about 30% and most preferably from 0 to about 
10% moderate acidity-type coffee beans. As used herein, "moderate 
acidity-type beans" are defined as beans that deliver between about 1.7 
and 1.9 titratable acidity as defined in the Analytical Methods section. 
These moderate acidity-type beans are typically referred to as 
intermediate grade coffees. Suitable intermediate quality coffees are the 
Brazilian coffees such as Santos and Paranas, African Naturals, and 
Brazils free from the strong Rioy flavor such as good quality Suldeminas. 
Intermediate coffees are characterized as having bland, neutral flavor and 
aroma, lacking in aromatic and high notes, and are generally thought to be 
sweet and non-offensive. 
Coffees useful in the present invention can also include from 0 to about 
30%, preferably from 0 to about 20% and most preferable from 0 to about 
10% low acidity-type coffee beans. As used herein, "low acidity-type 
beans" are defined as beans that deliver less than about 1.7 titratable 
acidity as defined in the Analytical Methods section. These low 
acidity-type beans are typically referred to as low grade coffees. 
Suitable low grade coffees having low acidity include Robustas, or low 
acidity natural Arabicas. These low grade coffees are generally described 
as having rubbery flavor notes and produce brews with strong distinctive 
natural flavor characteristics often noted as bitter. 
C. Roasting Coffee Beans 
Prior to roasting, the coffee beans can be partially predried to a moisture 
content of from about 3 to about 7%, preferably from about 5 to about 7%. 
Partial predrying can be desirable where a higher proportion of moderate 
to low acidity-type coffees are used make the moisture more uniform and 
thus less susceptible to tipping and burning. Partial predrying can be 
carried out according to any of the methods disclosed in U.S. Pat. No. 
5,160,757 (Kirkpatrick et al), issued Nov. 3, 1992 or U.S. Pat. No. 
5,322,703 (Jensen et al), issued Jun. 21, 1994, both of which are 
incorporated by reference to provide the indicated moisture content 
values. Preferably, the coffee beans are not predried prior to roasting 
and typically have moisture contents in the range of from about 8 to 14%. 
The coffee beans are carefully roasted under conditions that avoid tipping 
and burning of the beans. As used herein, the terms "tipping" and 
"burning" relate to the charting of the ends and outer edges of a bean 
during roasting. Tipping and burning of beans results in a burnt flavor in 
the resulting brewed beverage. Tipping and burning can be avoided by the 
combination of using high quality beans with minimal defects, roasting 
similar sizes and types together, uniform heat transfer (preferably 
convective), and controlling the heat input rate through the roast to 
prevent the edges of the beans from burning. 
In order to achieve the desired darker roast color without tipping or 
burning, the coffee beans are fast roasted in the process of the present 
invention. Fast roasters suitable for use in the present invention can 
utilize any method of heat transfer. However, convective heat transfer is 
preferred, with forced convection being most preferred. The convective 
media can be an inert gas or, preferably, air. Typically, the pre-dried 
beans are charged to a bubbling bed or fluidized bed roaster where a hot 
air stream is contacted with the bean. Suitable roasters capable of 
forming a fluidized bed of green coffee beans include the Jetzone RTM. 
roaster manufacture by Wolverine (U.S.), the Probat RTM. roaster 
manufactured by Probat-Werke (Germany), the Probat RT or RZ. roaster 
manufactured by Probat-Werke (Germany), the Burns System 90 roaster by 
Burns (Buffalo, N.Y.), the HYC roaster by Scolari Engineering (Italy), and 
the Neotec RFB by Neotec (Germany). Any other roasting equipment which 
causes a rapid heating of the bean such as that achieved through 
fluidization can be used. 
Roasting equipment and methods suitable for roasting coffee beans according 
to the present invention are described, for example, in Sivetz, Coffee 
Technology, Avi Publishing Company, Westport, Conn. 1979, pp. 226-246, 
incorporated herein by reference. See also U.S. Pat. No. 3,964,175 
(Sivetz) issued Jun. 22, 1976, which discloses a method for fluidized bed 
roasting of coffee beans. 
Other fast roasting methods useful in present invention are described in 
U.S. Pat. No. 5,160,757 (Kirkpatrick et al), issued Nov. 3, 1992; U.S. 
Pat. No. 4,737,376 (Brandlein et al.), issued Apr. 12, 1988; U.S. Pat. No. 
4,169,164 (Hubbard et al.), issued Sep. 25, 1979; and U.S. Pat. No. 
4,322,447 (Hubbard), issued Mar. 30, 1982, all of which are incorporated 
by reference. 
In the process of the present invention, the green coffee beans are fast 
roasted in from about 10 seconds to about 5.5 minutes, preferably in from 
about 1 to about 3 minutes, using air or another fluidizing heat exchange 
medium having a temperature of from about 350.degree. F. (177.degree. C.) 
to about 1200.degree. F. (649.degree. C.), preferably a temperature of 
from about 400.degree. F. (240.degree. C.) to about 800.degree. F. 
(427.degree. C.). The green coffee are fast roasted to an average color of 
from about 13 to about 19 Hunter "Hunter" units, preferably from about 14 
to about 18 Hunter "L" units, and most preferably from about 15 to about 
17 Hunter "L" units. The Hunter Color "L" scale system is generally used 
to define the color of the coffee beans and the degree to which they have 
been roasted. Hunter Color "L" scale values are units of light reflectance 
measurement, and the higher the value is, the lighter the color is since a 
lighter colored material reflects more light. Thus, in measuring degrees 
of roast, the lower the "L" scale value the greater the degree of roast, 
since the greater the degree of roast, the darker is the color of the 
roasted bean. This roast color is usually measured on the roasted, 
quenched and cooled coffee beans prior to subsequent processing (e.g., 
grinding and/or flaking) into a finished coffee product. 
As soon as the desired roast bean color is reached, the beans are removed 
from the heated gases and promptly cooled, typically by ambient air and/or 
a water spray. Cooling of the beans stops the roast-related pyrolysis 
reactions. Water spray cooling, also known as "quenching," is the 
preferred cooling method in the present invention. The amount of water 
sprayed is carefully regulated so that most of the water evaporates off. 
The roasted and quenched beans are further cooled with air. 
After cooling, the roast coffee beans of the present invention have a whole 
roast tamped bulk density of from about 0.27 to about 0.38 g/cc, 
preferably from about 0.29 to about 0.36 g/cc, more preferably from about 
0.30 to about 0.36 g/cc, and most preferably from about 0.30 to about 0.35 
g/cc. 
D. Grinding Roasted Beans 
The roasted coffee beans can then be ground using any conventional coffee 
grinder. Depending upon the specific particle size distribution desired in 
the final product of the present invention, the coffee fractions can be 
ground to the particle size distributions or "grind sizes" traditionally 
referred to as "regular," "drip," or "fine" grinds. For example, automatic 
drip coffee grinds typically have an average particle size of about 900 
.mu.m and percolator grinds are typically from about 1500 .mu.m to about 
2200 .mu.m. The standards of these grinds as suggested in the 1948 
Simplified Practice Recommendation by the U.S. Department of Commerce (see 
Coffee Brewing Workshop Manual, page 33, published by the Coffee Brewing 
Center of the Pan American Bureau) are as follows: 
______________________________________ 
Grind Sieve (Tyler) 
Wt. % 
______________________________________ 
Regular on 14-mesh 33 
on 28-mesh 55 
through 38-mesh 
12 
Drip on 28-mesh 73 
through 28-mesh 
27 
Fine through 14-mesh 
100 
on 28-mesh 70 
through 28-mesh 
30 
______________________________________ 
Typical grinding equipment and methods for grinding roasted coffee beans 
are described, for example, in Sivetz & Foote, "Coffee Processing 
Technology," Avi Publishing Company, Westport, Conn., 1963, Vol. 1, pp. 
239-250. 
E. Flaking Roast and Ground Coffee 
Coffee products according to the present invention can be flaked. Preferred 
flaked products are produced by grinding the roast coffee to an average 
particle size from about 300 to about 3000 .mu.m, normalizing the ground 
product, and then milling the coffee to a flake thickness of from about 2 
to about 40 thousandths of an inch (about 51 to about 1016 .mu.m), 
preferably from about 5 to about 30 (about 127 to about 762 .mu.m), most 
preferably from about 5 to about 20 (about 127 to about 508 .mu.m). 
Suitable methods and apparatus for flaking are disclosed in, for example, 
U.S. Pat. No. 3,615,667 (Joffe), issued Oct. 26, 1971; U.S. Pat. No. 
3,660,106 (McSwiggin et al), issued May 2, 1972; U.S. Pat. No. 3,769,031 
(McSwiggin), issued Oct. 30, 1973; U.S. Pat. No. 4,110,485 (Grubbs et al), 
issued Aug. 29, 1978; and 5,064,676 (Gore), issued--Nov. 12, 1991, all of 
which are incorporated by reference 
F. Characteristics of Beverage Obtained by Brewing Roast and Ground or 
Flaked Coffee Product 
1. Brew and Titratable Acidity 
An important characteristic of coffee beverages prepared from roast and 
ground or flaked coffee products according to the present invention is 
brew acidity. A high quality coffee brew is typically noted for its 
acidity. Coffee brews having high acidity are typically obtained from high 
quality beans. The problem previously with high yield, high mileage 
coffees is the use of less coffee (dilution), darker roasting (which tends 
to decrease acidity) and the use of stronger flavored Robustas (which 
generally have less acidity). Therefore, higher acidity becomes vital in 
maintaining a high quality brew for high mileage coffees. 
The ability of coffee to buffer pH changes in the mouth is its main 
indicator of acidity perception. This buffering capability can be measured 
by titrating the brew to pH 7 with sodium hydroxide and is thus referred 
to as Titratable Acidity (TA). Coffee beverages prepared from roast and 
ground or flaked coffee products according to the present invention have a 
TA of at least about 1.52, with a typical range of from about 1.6 to about 
3.0. Preferably, these coffee products have a TA of at least about 1.58, 
with a typical range of from about 1.8 to about 2.7. 
2. Cup Color and Brew Absorbance 
Another important characteristic of coffee beverages prepared from roast 
and ground or flaked coffee products according to the present invention is 
cup color. A dark cup of coffee is the first thing that a coffee drinker 
typically looks for. The coffee drinker will initially look at the cup of 
coffee to visually judge its strength. If the cup is too clear and allows 
light to transmit through it, it is usually considered too weak. However, 
if the brew in the cup is too dark so that virtually no light can transmit 
through it, it is usually considered too strong. 
Before ever tasting the coffee, the coffee drinker has thus judged in their 
mind as to what the strength will be, and by tasting it, confirms through 
taste what they have already visually seen. Therefore, an adequately 
strong cup of coffee must first visually look dark. Second, with the lower 
usage's of high yield, high mileage coffees, the consumer is constantly 
skeptical of the coffee being weak. Therefore, especially for high mileage 
coffees, the brew must be dark to prevent it from being judged weak. 
Traditionally, the darker the cup of coffee, the stronger it is. This 
observation is true of high mileage coffees. Except for the formation of 
offensive flavors (burnt, robbery, rioy), the darkness of the cup almost 
always correlates with the strength. Therefore, by measuring and 
controlling the cup darkness, one can not only predict the visual response 
to cup darkness, but can also somewhat predict its true strength (assume 
no offensive flavors). 
To technically measure the darkness of the coffee brew, a spectrophotometer 
is used to measure the amount of light absorbance by the liquid brewed 
coffee. A wavelength of 480 nanometers (urn) was chosen because it 
corresponds with the Brown Color absorbance on the visible spectrum. 
(Brown color is typically associated with stronger coffee brews.) This 
absorbance at 480 m correlates with the visually perceived darkness in the 
cup. 
For coffee beverages prepared from roast and ground or flaked coffee 
products according to the present invention have a brew absorbance of at 
least about 1.25, with a typical range of from about 1.3 to about 1.9. 
However, when the coffee beverage has a Titratable Acidity (TA) in the 
range of from about 1.52 to about 2.0, this brew absorbance is equal to or 
greater than the value defined by the equation: 
EQU 1.25+0.625.times.(2.0-TA)!. 
Preferably, when the coffee beverage has a TA in the range of from about 
1.58 to about 2.2, this brew absorbance is equal to or greater than the 
value defined by the equation: 
EQU 1.25+0.625.times.(2.2-TA)!. 
3. Brew Solids 
Another important characteristic of coffee beverages prepared from roast 
and ground or flaked coffee products according to the present invention is 
the level of brew solids. Brew solids are simply the solids remaining 
after oven drying the brewed coffee. Brew solids is an indication of the 
mass transfer that has occurred from the solid grounds to the water phase 
during brewing. While the level of brew solids is a good indicator of the 
efficiency of the extraction and completeness, it does not discriminate as 
to what compounds are extracted. Indeed, green coffee has a considerable 
fraction of extractable brew solids, even though the subsequent brew 
prepared from this green coffee lacks coffee flavor. 
High yield, high mileage coffees have concentrated on extracting more of 
the available brew solids. This has been beneficial in providing good 
extraction of the majority of the compounds that are low molecular weight 
(i.e., simple sugars). However, until the present invention, very little 
attention has been paid to studying how to make and extract more of the 
strength compounds. 
It is believed that the compounds that contribute to the additional 
strength and cup darkness of coffee beverages prepared from roast and 
ground or flaked coffee products according to the present invention is due 
to very high molecular weight molecules such as polysaccharides. These 
compounds may not be at very high levels, but are very functional because 
of their size, geometry and full chemical structure. The low level of 
these very functional molecules can be almost insignificant when compared 
to the total brew solids. 
Although the level of brew solids is an incomplete measurement of brew 
strength, it is still a good indicator of overall extraction efficiency. 
Accordingly, coffee products according to the present invention maintain a 
high extraction efficiency, as measured by brew solids. For coffee 
beverages prepared from roast and ground or flaked coffee products 
according to the present invention, the level of brew solids is in the 
range of from about 0.4 to about 0.6%. Preferably, coffee beverages 
prepared from coffee products according to the present invention have a 
level of brew solids in the range of from about 0.42 to about 0.58%. 
4. Relationship of Brew Absorbance to Roast Color of Coffee 
Another important characteristic of roast and ground or flaked coffee 
products according to the present invention is the relationship of brew 
absorbance to roast color. There is a natural tendency as the coffee is 
roasted darker for it to produce more of the strength and color compounds. 
Coffee products according to the present invention provides coffee 
beverages having an increased brew absorbance at a given degree of roast 
color. This can be quantified by the relationship of the brew absorbance 
of the coffee beverage produced from the coffee product relative the roast 
color of the coffee product. Coffee products according to the present 
invention preferably have a brew absorbance equal to or greater than the 
value defined by the equation: 
EQU 2.475-0.075.times.(Hunter L-color of coffee)! 
G. Analytical Methods 
1. Whole Roast Tamped Bulk Density Determination 
This method determines the degree of puffing that occurs in the roasting of 
green coffee and is applicable to both decaffeinated and non-decaffeinated 
whole roasts. 
a. Apparatus 
Weighing container: 1,000 ml stainless steel beaker or equivalent 
Measuring container: 1,000 ml plastic graduated cylinder; 5 ml graduations 
Scale: 0.1 gm sensitivity 
Vibrator: Syntron Vibrating Jogger; Model J-1 or equivalent. Syntron 
Company--Homer City, Pa. 
Funnel: Plastic funnel with tip cut off to about 1" outlet 
Automatic Timer: Electric, Dimco-Gray; Model No. 171 or equivalent 
b. Operation 
Weigh 200 g of whole bean coffee to be tested into beaker. Place the 
graduated cylinder on the vibrator. Using the funnel, pour the coffee 
sample into the cylinder. Level the coffee by gently tapping the side of 
the cylinder. Vibrate 30 seconds at No. 8 setting. Read volume to nearest 
5 ml. Tamped density can be determined by dividing the weight of the 
coffee by the volume occupied (after vibrating) in the graduated cylinder. 
For standardizing the measurements between different coffees, all density 
measurements herein are on a 4.5% adjusted moisture basis. For example, 
200 grams of whole bean coffee having a 2% moisture content would contain 
196 g of dry coffee and 4 g of water. If the volume was 600 cc, the 
unadjusted density would be 200 g/600 cc=0.33 g/cc. On a 4.5% adjusted 
moisture basis, the calculation is: 4.5%.times.200 gms=9 gms water. To 
make the density calculation on an adjusted moisture basis, take 196 g dry 
coffee+9 g water=205 g total. Adjusted density=205 g/600 cc=0.34 g/cc. 
2. Roasted Coffee Color 
The Hunter Color "L" scale system is generally used to define the color of 
the coffee beans and the degree to which they have been roasted. A 
complete technical description of the system can be found in an article by 
R. S. Hunter "Photoelectric Color Difference Meter," J. of the Optical 
Soc. of Amer., 48, 985-95 (1958). In general, it is noted that Hunter 
Color "L" scale values are units of light reflectance measurement, and the 
higher the value is, the lighter the color is since a lighter colored 
material reflects more light. In particular, in the Hunter Color system 
the "L" scale contains 100 equal units of division; absolute black is at 
the bottom of the scale (L=0) and absolute white is at the top (L=100). 
Thus, in measuring degrees of roast, the lower the "L" scale value the 
greater the degree of roast, since the greater the degree of roast, the 
darker is the color of the roasted bean. 
3 Brewing 
Coffee is brewed on a Bunn OL-35 automated drip brewer. Coffee filters are 
12 cup oxygen processed Bunn Coffee filters (Reg. 6001). One ounce of 
coffee is added to the filter in the basket. The brewer is supplied with 
distilled water and feeds 1860 ml at 195.degree. F. (90.degree. C.) in 146 
seconds to the brew basket. Brewed coffee is collected in a carafe and 
then mixed. Samples for brew solids, brew absorbance, and Titratable 
Acidity are then collected. 
4. Brew Absorbance 
The brewed coffee is placed in a 12 ml sealed vial and then cooled for 10 
minutes in a water bath at 29 degrees C. The sample is then transferred to 
a cuvette and the absorbance is measured in a Milton Roy Spectrophotometer 
401 at 480 nm wavelength. 
5. Brew Solids 
The brewed coffee is placed in a 12 ml sealed vial and allowed to cool. The 
sample is then analyzed for solids content by index of refraction using a 
Bellingham & Stanley RFM 81, where the sample temperature during the 
measurement is maintained at 29.degree. C. The readings are correlated 
with readings of reference solutions of known brew solids content based on 
oven drying techniques using a correlation of: 
EQU Refractive Index=0.001785.times.(% brew solids)+1.331995 
6. Titratable Acidity 
From a mixed carafe, 100 g of a coffee brew is collected, covered with a 
lid, and allowed to cool. The coffee brew is then titrated to 7 pH using 
0.1N sodium hydroxide solution, recording the milliliters required as the 
Titratable Acidity (ml 0.1N NaOH). 
7. Green Coffee Acidity 
To assess the acidity level in green coffee, the coffee is roasted in a 
standard way, to a standard condition, ground and flaked, brewed and then 
the Titratable Acidity measured: A 100 pound charge of coffee is fed to a 
Thermalo roaster, Model Number 23R, manufactured by Jabez Burns and a gas 
burner input rate of about 1.4 million BTU/hr. such that the coffee is 
roasted to color of 17 Hunter L in approximately 210 seconds. The coffee 
is then quenched to 4.5% moisture and cooled. After grinding and 
subsequent flaking to a 14 mil thickness, the product is brewed (per 
method 3 above) and the Titratable Acidity is measured (per method 6 above 
method).

H. Examples 
Example 1 
Washed Arabica coffees from Guatemala having a Standard Green Acidity of 
2.2 were fast roasted on a batch Thermalo roaster with a 100 pound charge 
to a roasted bean temperature of 441.degree. F. (227.degree. C.), 
achieving a roast color of 15.6 Hunter L with a roast time of 226 seconds. 
The coffee was then quenched to 3.9% moisture and yielded a whole roast 
density of 0.32 g/cc. The coffee was then ground to an average particle 
size of 850 .mu.m and then flaked to a 14 mil flake thickness. The product 
provided a coffee brew with a brew absorbance of 1.72, a Titratable 
Acidity of 1.77, and brew solids of 0.51%. 
Example 2 
Washed Arabicas from Colombia having a Standard Green Acidity of 2.7 were 
fast roasted on a Probat RZ2500SY continuous roaster with a roast time of 
120 seconds, a hot air temperature of 635.degree. F. (335.degree. C.), 
achieving a roast color of 15.9 Hunter L and a whole roast density of 0.36 
g/cc. The roasted coffee was quenched to 4.7% moisture and then cooled 
with air. The cooled beans were than ground to an average particle size of 
950 gm and then flaked to a 14 mil flake thickness. The product provided a 
coffee brew with a brew absorbance of 1.52, a Titratable Acidity of 2.60, 
and brew solids of 0.49%. 
Example 3 
A blend of Arabicas from Central and South America having a Standard Green 
Acidity of 2.4 were fast roasted on a Probat RZ25005Y continuous roaster 
with a roast time of 120 seconds, a hot air temperature of 675.degree. F. 
(357.degree. C.), achieving a roast color of 16.7 Hunter L and a whole 
roast density of 0.34 g/cc. The roasted coffee was quenched to 4.4% 
moisture and then cooled with air. The cooled beans were than ground to an 
average particle size of 1000 .mu.m and then flaked to a 14 mil flake 
thickness. One ounce of the product was added to a filter pack with 
impermeable side walls. The filter pack coffee product provided a coffee 
brew with a brew absorbance of 1.44, a Titratable Acidity of 2.39, and 
brew solids of 0.50%. 
Example 4 
The whole roasted beans from Example 2 were ground to an average particle 
size of 900 .mu.m and then flaked to a 10 mil flake thickness. The product 
provided a coffee brew with a brew absorbance of 1.60, a Titratable 
Acidity of 2.70, and brew solids of 0.51%. 
Example 5 
A blend of Decaffeinated Washed Arabicas from Central America and Colombia 
having a Standard Green Acidity of 2.35 were fast roasted on a Probat 
RZ2500SY continuous roaster with a roast time of 120 seconds, a hot air 
temperature of 607.degree. F. (319.degree. C.), achieving a roast color of 
15.9 Hunter L and a whole roast density of 0.36 g/cc. The roasted coffee 
was quenched to 4.5% moisture and then cooled with air. The cooled beans 
were than ground to an average particle size of 1025 .mu.m and then flaked 
to a 14 mil flake thickness. The product provided a coffee brew with a 
brew absorbance of 1.42, a Titratable Acidity of 2.30, and brew solids of 
0.44%. 
Example 6 
The whole roasted beans from Example 1 were blended with whole roasted 
beans from Example 2 in a weight ratio of 70:30. This bean blend was then 
ground to an average particle size of 900 .mu.m and then flaked to a 14 
mil flake thickness. The product provided a coffee brew with a brew 
absorbance of 1.67, a Titratable Acidity of 2.02, and brew solids of 
0.50%. 
Example 7 
The whole roasted beans from Example 2 were ground to an average particle 
size of 390 .mu.m. The product provided a coffee brew with a brew 
absorbance of 1.52, a Titratable Acidity of 2.50, and brew solids of 
0.46%. 
Example 8 
Natural Robustas from Uganda having a Standard Green Acidity of 1.63 were 
fast roasted on a batch Thermalo roaster with a 100 pound charge to a 
roasted bean temperature of 448.degree. F. (231.degree. C.), achieving a 
roast color of 15.3 Hunter L with a roast time of 219 seconds. The coffee 
was then quenched to 4.0% moisture and yielded a whole roast density of 
0.34 g/cc. This whole roast was then ground to an average particle size of 
400 .mu.m. This ground product was then blended with the flaked coffee 
from Example 4 in weight ratio of 5:95. (At the 5:95 ratio, the equivalent 
Standard Green Acidity for the total blend was 2.6.) The blended product 
provided a coffee brew with a brew absorbance of 1.77, a Titratable 
Acidity of 1.89, and brew solids of 0.50%. 
Example 9 
The ground coffee from Example 7 was blended with flaked coffee from 
Example 1 in a weight ratio of 50:50. The product provided a coffee brew 
with a brew absorbance of 1.67, a Titratable Acidity of 2.15, and brew 
solids of 0.47%. 
Example 10 
The flaked coffee from Example 4 was brewed using a standard brew set up, 
except that the brewer was modified so that only 750 ml of water was added 
in 85 seconds to the brew basket The resultant brew resembled an 
"espresso" style coffee beverage which could be used for Cappuccinos, 
Lattes, etc. Also, this concentrated brew was diluted with 1100 ml of hot 
distilled water to a final normal brew volume of 1800 ml which provided a 
coffee brew with a brew absorbance of 1.38, a Titratable Acidity of 2.38, 
and brew solids of 0.45%. In addition, the amount of water added to the 
brewer was varied from 400 to 1200 ml to change the strength of the 
"espresso" style coffee beverage. Also, the coffee weight added to the 
brew basket was varied from 1 to 3 ounces to change the strength of the 
"espresso" style coffee beverage. Also, the equivalent amount of water 
added to dilute the coffee was varied from 300 to 2000 ml to deliver a 
range of coffee strengths from "very strong," "strong," "medium," "mild," 
to "very mild."