i
Facts About Drip Coffee Makers
Oregon State University Extension Service
Reprinted October 1978, EC 928
Factors Affecting Quality
Drinking coffee has become part of our social
custom. It is often the first thing you are offered as a guest in someone's home, at an interview, even when you visit the doctor, dentist, or
beauty shop. On TV, we're exposed to Mrs. Olson
popping up when she is least expected, or the
"poor husband" who only gets half-a-cup because
his "little wife" is trying to "decaffeinate" him.
Instant coffee lets us have coffee in just minutes, but many people miss the brewed flavor and
aroma. The concern has been to devise a way to
extract the brew from the bean and meet today's
need for speed and convenience. With rising coffee prices, it becomes even more critical to get a
good brew with a minimum of waste from grounds
used.
These concerns have caused many coffee
drinkers to put away certain models of coffee makers. Though they may brew a good cup of coffee,
some coffee makers have been found to be too
much trouble to use and clean, and take too much
brewing time.
The latest compromise toward quickly brewing a good cup of coffee is the electric drip coffee
maker.
The quality of coffee is affected by these
factors regardless of the model of coffee maker
used:
— freshness of the ground coffee
— fineness of the grind
— minerals present or not present in the
water
— length of time water remains in contact
with ground coffee
— temperature of water during extraction
— fineness or coarseness of the filter
— temperature at which coffee is held
In most drip-type models the coffee is accumulated in a serving carafe which sits on a heating element. The main heating element should
turn off when brewing is finished and hold the
brew at a "keep warm" or "ready to serve"
temperature.
Coffee Makers
Though there are many types of coffee makers, this fact sheet is concerned with two driptype models, the percolator type and the flowthrough type. The percolator type pumps water
over the grounds. In this model, water is placed
in a reservoir, fed into a heating chamber, forced
up a feed tube and sprayed over the grounds,
then accumulated for serving. The flow-through
type is the second drip-type to be discussed. In
this model, the water reservoir is over the
grounds. Gravity causes the water to flow past
a heating coil, down into a filter basket holding
the grounds, and into a reservoir where it is
accumulated for serving.
Another type heats the water in the reservoir; then the hot water flows through the
grounds in a filter basket where extraction of
the coffee takes place. The brew is then accumulated for serving.
Temperatures
The Coffee Brewing Center (CBC), a tradesupported research and testing center, recommends:
— holding temperature should be between
185° F and 190° F for at least V2 hour
after preparation of the beverage
— start with 6 ounces of water and 2 level
tablespoons of fresh coffee of the model's recommended grind
— water heated to not less than 185° F and
not more than 205° F
— water mixed evenly with grounds and
held in contact:
Regular grind — 8 minutes
Drip grind
— 6 minutes
Fine grind
— 4 minutes
What is a Good Cup of Coffee?
This is a case of personal preference. Generally the darker brews are stronger in flavor,
and also the more turbid (dense) the brew the
more flavorful the beverage. If strong brew is
preferred, a maker whose coffee is darker and
more dense (turbid) will be the preference.
If you are not a lover of strong brew, a coffee
maker producing a lighter beverage will be your
choice. Those that prefer a "weaker" brew
might remember it is more desirable that coffee
be brewed full strength and then diluted with hot
water to the taster's preference.
To Buy or Not to Buy
—A coffee maker works most efficiently
when used to capacity. It would be a good decision for those who consistently brew only a
small amount of coffee to purchase a coffee
maker with a maximum capacity close to the
most often needed amount of coffee. Those who
plan to use the maximum or near maximum capacity most of the time, might best consider a
coffee maker with the highest maximum capacity. If demands for coffee vary, it's best to consider one's average needs.
—Speed of brewing refers to the time it takes
to brew a pot of coffee. A coffee maker that delivers 63.5 Btu per minute will make coffee twice
as fast as one that delivers heat at 31.7 Btu per
minute.
—Other uses might be considered but remember: Coffee makers heat water. No other
liquid should be put through the filter system
other than the exception* discussed below. Putting water through the brewing cycle without
coffee grounds or filter will produce hot water for
soups, tea, or hot cocoa. The hot plate under the
* Use of liquid other than water—vinegar: As with other
water-heating devices, a deposit or scale of minerals from
the water builds up inside the heating areas and may clog
the passageway. Manufacturers recommend running a solution of vinegar and water through the brewing cycle several times to dissolve deposited minerals. This is called
de-liming. Be sure to rinse the coffee maker several times
by running clear water through several brewing cycles with
no coffee. Specific models may have de-liming processes
included in the use and care manuals, but essentially the
process is the same.
carafe will then maintain hot water for these
alternative uses.
If a standard filter is required, you are more
likely assured easy replacement. Models which
require a limited specification for replacement
may cause inconvenience and/or the model may
become obsolete faster because the supply of
filters is no longer available. Filter costs should
also be figured in when purchase price is being
considered. Some models do not have separate
filters.
—Capacity tells us how much coffee the
model will brew in 6 oz. cups. Models come with
either a carafe with cup markings on the side or
a separate calibrated flask in which you measure the volume of water for the amount of coffee
you want. Some water is absorbed as it is
passed through the filter so you do lose a bit of
the volume in the brewing. Remember: Your
coffee mugs may not be the same size as the
calibrated cups, so serving adjustments will
have to be made with experience.
—Size—not only in capacity but for use and
storage. Because these types of coffee makers
are designed for convenience, where you will
keep the appliance should be an important consideration. Already crowded work areas in the
kitchen may need reconsideration before the
additional item is added. If you plan to store it
in a cupboard—think again before you buy. How
often would you bring it out to make just a few
cups of coffee? Will it be used by the person for
whom you want to buy one?
These points for consideration should be
helpful as you evaluate a piece of equipment
which essentially heats water.
Prepared by Janice M. Weber
Extension family resource management specialist
Oregon State University
OREGON STATE UNIVERSITY
EXTENSION
a SERVICE
Extension Service, Oregon State University, Corvallls. Henry A. Wadsworth,
duced and distributed in furtherance of the Acts of Congress of May 8 and
cooperative program of Oregon State University, the U. S. Department of
Extension invites participation in its programs and offers them equally to
director. This publication was proJune 30, 1914. Extension work It a
Agriculture, and Oregon counties.
all people, without discrimination.
Drip-Filter Coffee Makers
Oregon State University Extension Service, May 1977, EC 928
Factors Affecting Quality
Drinking coffee has become part of our social
custom. It is often the first thing you are offered as a guest in someone's home, at an interview, even when you visit the doctor, dentist, or
beauty shop. On TV, we're exposed to Mrs. Olson
popping up when she is least expected, or the
"poor husband" who only gets half-a-cup because
his "little wife" is trying to "decafinate" him.
Instant coffee lets us have coffee in just minutes, but many people miss the brewed flavor and
aroma. The concern has been to devise a way to
extract the brew from the bean and meet today's
need for speed and convenience. With rising coffee prices, it becomes even more critical to get a
good brew with a minimum of waste from grounds
used.
These concerns have caused many coffee
drinkers to put away certain models of coffee makers. Though they may brew a good cup of coffee,
some coffee makers have been found to be too
much trouble to use and clean, and take too much
brewing time.
The latest compromise toward quickly brewing a good cup of coffee is the electric drip coffee
maker.
The quality of coffee is affected by these
factors regardless of the model of coffee maker
used:
— freshness of the ground coffee
— fineness of the grind
— minerals present or not present in the
water
— length of time water remains in contact
with ground coffee
— temperature of water during extraction
— fineness or coarseness of the filter
— temperature at which coffee is held
In most drip-type models the coffee is accumulated in a serving carafe which sits on a heating element. The main heating element should
turn off when brewing is finished and hold the
brew at a "keep warm" or "ready to serve"
temperature.
Coffee Makers
Though there are many types of coffee makers, this fact sheet is concerned with two driptype models, the percolator type and the flowthrough type. The percolator type pumps water
over the grounds. In this model, water is placed
in a reservoir, fed into a heating chamber, forced
up a feed tube and sprayed over the grounds,
then accumulated for serving. The flow-through
type is the second drip-type to be discussed. In
this model, the water reservoir is over the
grounds. Gravity causes the water to flow past
a heating coil, down into a filter basket holding
the grounds, and into a reservoir where it is
accumulated for serving.
Another type heats the water in the reservoir; then the hot water flows through the
grounds in a filter basket where extraction of
the coffee takes place. The brew is then accumulated for serving.
Temperatures
The Coffee Brewing Center (CBC), a tradesupported research and testing center, recommends:
— holding temperature should be between
185rF and 190oF for at least Vz hour after
preparation of the beverage
— start with 6 ounces of water and 2 level
tablespoons of fresh coffee of the model's recommended grind
— water heated to not less than 185CF and
not more than 205oF
— water mixed evenly with grounds and
held in contact:
Regular grind — 8 minutes
Drip grind
— 6 minutes
Fine grind
— 4 minutes
V
What is a Good Cup of Coffee?
This is a case of personal preference. Generally the darker brews are stronger in flavor,
and also the more turbid (dense) the brew the
more flavorful the beverage. If strong brew is
preferred, a maker whose coffee is darker and
more dense (turbid) will be the preference.
If you are not a lover of strong brew, a coffee
maker producing a lighter beverage will be your
choice. Those that prefer a "weaker" brew
might remember it is more desirable that coffee
be brewed full strength and then diluted with hot
water to the taster's preference.
Points to Consider About to Buy or Not
Buy
Ay
—A coffee maker works most efficiently
when used to capacity. It would be a good decision for those who consistently brew only a
small amount of coffee to purchase a coffee
maker with a maximum capacity close to the
most often needed amount of coffee. Those who
plan to use the maximum or near maximum capacity most of the time, might best consider a
coffee maker with the highest maximum capacity. If demands for coffee vary, it's best to consider one's average needs.
—Speed of brewing refers to the time it
takes to brew a pot of coffee. A coffee maker
..-with a brewing speed JOJ 63.5 Btu per minute
vvrfTmaTce'coffee twice as fast as one that delivers heat at 31.7 Btu per minute.
—Other uses might be considered but remember: Coffee makers heat water. No other
liquid should be put through the filter system
other than the exception* discussed below.
Putting water through the brewing cycle without coffee grounds or filter will produce hot
water for soups, tea, or hot cocoa. The hot plate
* Use of liquid other than water—vinegar: As with
other water-heating devices, a deposit or scale of minerals from the water builds up inside the heating areas
and may clog the passageway. Manufacturers recommend
running a solution of vinegar and water through the brewing cycle several times to dissolve deposited minerals. This
is called de-liming. Be sure to rinse the coffee maker several times by running clear water through several brewing cycles with no coffee. Specific models may have deliming processes included in the use and care manuals, but
essentially the process is the same.
under the carafe will then maintain hot water
for these alternative uses.
If a standard filter is required, you are more
likely assured easy replacement. Models which
require a limited specification for replacement
may cause inconvenience and/or the model
may become obsolete faster because the supply of filters is no longer available. Filter costs
should also be figured in when purchase price
is being considered. Some models db not have
separate filters.
—Capacity tells us how much coffee the
model will brew in 6 oz. cups. Models come
with either a carafe with cup markings on the
side or a separate calibrated ■flask in which you
measure the volume of water for the amount of
coffee you want. Some water is absorbed as it is
passed through the filter so you do lose a bit of
the volume in the brewing. Remember: Your
coffee mugs may not be the same size as the
calibrated cups, so serving adjustments will
have to be made with experience.
—Size—not only in capacity but for use and
storage. Because these types of coffee makers
are designed for convenience, where you will
keep the appliance should be an important consideration. Already crowded work areas in the
kitchen may need reconsideration before the
additional item is added. If you plan to store it
in a cupboard—think again before you buy. How
often would you bring it out to make just a few
cups of coffee? Will it be used by the person for
whom you want to buy one?
These points for consideration should be
helpful as you evaluate a piece of equipment
which essentially heats water.
Prepared by Janice M. Weber
Extension home management specialist
Oregon State University
OREGON STATE UNIVERSITY
EXTENSION
a SERVICE
Extension Service, Oregon State University, Corvallis, Henry A. Wadsworth,
duced and distributed in furtherance of the Acts of Congress of May 8 and
cooperative program of Oregon State University, the U. S. Department of
Extension invites participation in its programs and offers them equally to
director. This publication was proJune 30, 1914. Extension work is a
Agriculture, and Oregon counties.
all people, without discrimination.