|
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USA's Micro Matic Certified Beer Dispensing Technicians Service and Install
Your Beer System Without Worry!
Residential
and Commercial Applications.
Whether its
upgrading an existing system or installing a new system, Pub Stuff USA's technicians
will have you serving the freshest beer in town! We also offer contract line cleaning.
Contact us
at (609) 489-0501 for more details
Click
on the topic you wish to read more about:
•
Clean Beer Lines Dispense Quality Beer
• The Importance of Beer Line Cleaning
• Brewery Policies on Beer Line Cleaning
• Line Cleaning Equipment and Procedures
• Draft Beer Temperature Overview
• Three Types of Draft Beer Dispensing
Systems
• Draft Beer System Maintenance
• Foam on Beer Detectors
• Dispensing Beer with Blended Gas
• Balancing a Direct Draw Draft Beer System
• Presenting Draft Beer to the Customer
•
Beer Tap Faucets
•
Gas Regulators Used in Dispensing Draft Beer
Clean
Beer Lines Dispense Quality Beer
Foamy draft beer
can be caused by the build up of bacteria, yeast, mold, and beer stones within
a beer line. Un-clean beer lines lower the quality and taste of beer. It is
important to regularly clean beer lines, faucets, and keg couplers to ensure
the dispense of high quality beer.
The simple process
of cleaning takes only a few minutes and is easily accomplished by use of either
a hand pumped cleaning bottle or pressurized cleaning bottle. This process involves
pumping water mixed with cleaning chemical into the beer line and letting it
soak for the time prescribed by the chemical manufacturer. Then thoroughly flushing
the beer line with water to remove all traces of the cleaning chemical. The
last and most often overlooked step is to soak the keg coupler and faucet in
water with cleaning chemical then brush them clean with a cleaning brush and
rinse them clean with water. As maintenance issue, after cleaning it is always
a good time to make sure the probe o-rings and bottom seal on the keg coupler
are in good condition. As well as the friction washer, coupling washer, and
shaft seat on the faucet are in good condition. You should also make sure the
probe o-rings on the keg coupler are properly lubricated (with a food grade
lubricant) to allow the keg coupler to work freely and prevent wear and tear
that can occur when the keg coupler is tapped and untapped to the keg. For a
better understand of these part, see a typical keg coupler diagram and faucet
diagram.
For residential
applications, cleaning should be performed after every keg or at a minimum of
every two weeks. Routine cleaning is essential to maintain quality and fresh
taste. For commercial applications, cleaning should be performed at least every
two weeks or following brewery recommendations and/or state guidelines. PLEASE
NOTE: Only use cleaning chemicals specifically manufactured for beer line cleaning.
Only chemicals specifically manufactured for beer line cleaning will dissolve
the buildups of bacteria, yeast, mold, and beer stone that occur with draft
beer. And for safety it is very important that all directions on these cleaning
chemicals be followed completely.
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The
Importance of Beer Line Cleaning
A
brewer may take up to several months to brew, finish, and package a keg of beer.
The quality and flavor of that beer can be ruined in the few seconds it takes
for a beer to travel from a keg to the faucet in a draft system that has not
been properly maintained.
The enemies of
draft beer may include the following:
Yeast
- May result from an extremely small amount left from the brewing process, or
it may be wild yeast which floats in the air. It is usually found as a surface
growth on components of a beer system that is exposed to the air such as faucets,
keg couplers, and drains and can be recognized by its white or grey color.
Mold – is usually introduced into a beer system through exposure to the air.
It also is usually found as surface growth on components of a beer system that
are exposed to air such as the faucets, keg couplers, and drains and is usually
brown or black in color.
Beer stone
– The raw materials, grains and water, that are used in the brewing
process contain calcium. Oxalic acids or salts are present in hops and may be
created during the process of changing barley into malt. The combination of
these ingredients and the fact that beer is dispensed at cold temperatures may
result in Calcium Oxalate deposits known as beer stone. Beer
stone will build up and eventually flake off on the inside of the beer tubing
if the system is not properly maintained. High amounts of beer stone may also
have a negative effect on taste. These flakes are often grey or brown in color.
Bacteria – Bacteria found in beer are not significantly hazard to human health;
however, its effect is noticeable in the appearance, aroma, and taste of beer.
The presence of bacteria results in an “off taste” and cloudy appearance
that makes beer unappetizing. A beer that tastes sour, vinegar-like, or smells
like rotten eggs may indicate a beer system is contaminated with beer spoiling
bacteria.
Failing to clean and maintain a beer system on a regular basis will result in
the ability to pour a “brewery fresh” beer.
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Brewery
Policies on Line Cleaning
Brewers know the
importance of proper line cleaning and the impact it has on their products,
reputation, and sales. Most breweries publish beer line cleaning procedures
and schedules within their quality assurance policies. These policies are monitored
and enforced by contracted distributors where legal, depending on state statutes.
A review of the
individual brewery policies reveals that there is a consensus that it is important
to clean a draft system at a minimum of once every two weeks. Long draw beer
systems in excess of 25 feet in length, and accounts serving large volumes of
draft beer should be cleaned more frequently. Once a week is the recommended
frequency for cleaning lines in these high volume and long-draw accounts.
The cleaning process
and chemicals used to clean and sanitize the system will also vary with the
type and length of the beer dispensing system. The next section will describe
the variables to consider when assessing the best method for cleaning.
Line
Cleaning Chemicals
An effective line-cleaning chemical must be used when cleaning lines to attack
the enemies of beer that were previously mentioned. Line cleaners will be either
caustic with a high PH, or acidic with a low PH depending on the line conditions
and the type of system being cleaned.
Alkaline
(Caustic) cleaners attack and dissolve proteins, carbohydrates, hop
resins and bio-films. They also are very effective in killing mold, bacteria,
and yeast.
Acid line
cleaners dissolve minerals that are commonly referred to as beer stone.
Both caustic and
acid line cleaners can be very dangerous if not handled and used properly. You
should always follow the directions printed on the package and strictly adhere
to the manufacturer’s recommended concentration levels. Using the proper
concentration level is the safest and most cost-effective method for beer line
cleaning.
You should always
wear personal safety equipment including eye protection and rubber gloves when
handling line-cleaning chemicals. It is also important to never mix an alkaline
solution with an acid solution.
Brewery tested
and approved line cleaners are available. The reliable cleaning formulas feature:
The latest surfactant, which reduces surface tension, resulting in fast easy
cleaning. Effectiveness in all water conditions. Low foam formula
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Line Cleaning Equipment & Procedures
There are two
unique methods employed to clean draft beer dispensing systems:
Pressurized
Cleaning – This method usually is done by putting the cleaning
agent into a plastic or metal container and forcing it through the beer lines
via the use of a hand pump or gas pressure (CO2 or compressed air).
The containers
have a means of to connect the beer system either through a faucet adaptor or
a coupler for the beer valve (tap). Pressurized cleaning containers make it
quick and easy to clean picnic pumps, direct draw and short-draw systems of
less than twenty feet in length.
Re-circulating
Cleaning – Uses a motorized electric pump that is especially
built for beer line cleaning. These pumps are equipped with connectors to enable
the cleaning the system from the tap or faucet end.
Re-circulating
cleaning is always the best choice for long draw systems that are over twenty
feet. The turbulent flow of the cleaning solution is up to eighty times more
effective than simply allowing the cleaning solution to soak inside the beer
lines as is the case through pressurized cleaning.
No matter what
type of cleaning system you are using, Pub Stuff USA recommends a proven three
step cleaning procedure to ensure that the lines are thoroughly cleaned and
sanitized in order to maintain the integrity of the beer.
• Begin
by flushing the beer from the lines with water. This eliminates beer from
the lines so as not to dilute the cleaning properties of the chemical.
• Next,
clean the lines with the appropriate solution. Allow chemicals to circulate
or soak in the lines for at least ten minutes. Always be sure to follow the
manufacturer’s recommendations on proper mix ratio, correct temperature,
and ample contact time.
• The
final step is to thoroughly flush the chemical from the lines with water.
After the water rinse cycle is completed, it is recommended to check the ph
level with a ph tester or litmus paper to insure that no cleaning solution
remains in the lines. Then reconnect the kegs and allow some beer to run through
the faucet and discard to make sure all the lines are completely refilled
with beer.
It is important to note that not only should the beer lines be cleaned at
least every fourteen days but so should the keg couplers and faucets. These
components also require cleaning because they too are in contact with the
beer and need to be maintained at the same level as the beer lines.
Following the three-step
cleaning process, along with these guidelines will allow you to maintain your
draft beer system while providing brewery fresh draft beer each and every day.
Serving great tasting draft beer will keep your customers and your friends coming
back for more.
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Draft
Beer Temperature Overview
Beer
Temperature Introduction
One
of the most essential elements for the proper operation of any draft beer dispensing
system is a consistent temperature.
Purpose
The purpose of
this section is to explain the relationship between draft beer and temperature.
To present the cause and effect of temperature changes on beer in kegs. To bring
awareness to the problems that improper temperatures impart on the beer and
the financial and beer quality consequences that may result.
The
Most Common Draft Beer Problem
The most common
problem with a draft system is incorrect temperature.
When the beer gets
warm, it foams and the retailer loses profits, because foam is approximately
25% beer. If the retailer is throwing away 25% of the beer in a keg, they are
pouring away several hundreds of dollars in lost profits a week.
When beer gets
too cold, the carbonation in the beer stays in the beer until it is consumed
and released in the customer’s stomach. This also results in lost profits
because the customer cannot drink as much.
So, either way,
if the beer is too warm or the beer is too cold, the beer’s quality is
at risk and profits from beer sales will be lost.
The Proper
Beer Temperature
What is the proper
temperature for storing and for serving draft beer?
The answer to both
questions is 38 degrees F.
38 degrees F temperature,
applies whether the beer is a domestic beer or an imported one. The same holds
true whether or not the draft beer is pasteurized.
The reason for
this is that beer stored at 38 degrees F will retain the level of carbonation
that was created during the brewing process.
If Beer’s
Temperature is Too Warm
Allowing keg beer
to warm up will cause the carbonation to be released from the beer while it
is still in the keg, causing foaming. The foaming occurs because the pressure
being applied to the keg is no longer enough to keep the carbonation in the
beer.
This results in
foam (profits) being poured down the drain because the foam is released when
the faucet is opened.
! Once the carbonation
in the beer has been released, it will affect the taste and appearance of the
product being served.
If Beer’s
Temperature is Too Cold
Having the beer
too cold causes the carbonation to stay in the beer. This results in the beer
glass being overfilled, and profits being lost. In addition, if the keg is too
cold and the applied pressure remains at the same setting for 38 degrees, too
much pressure is applied and the beer may over carbonate if not used in a short
time. The beer will be wild and foamy at the faucet.
Beer
Temperature Changes
Taking the
Beer’s Temperature
Thermometers should
be placed in liquid inside the beer cooler in order to accurately measure the
temperature in the cooler.
The temperature
of the beer at the faucet should also be measured to determine if the beer is
warming up as it travels through the system from the keg to the faucet.
When possible,
the temperature of the beer inside the keg should also be taken in order to
determine whether or not the proper temperature is achieved. When using a kegerator
or a through-the-wall direct draw system, after pouring off a couple of glasses,
you will be pouring beer directly from the keg. In long draw systems, to measure
the temperature of the beer in the keg, you will need either a temperature strip
mounted on the side of the keg, or a hand held pump to dispense beer right from
the keg.
Why Take the
Beer's Temperature?
It takes approximately
4 hours for a keg of beer to warm up from 38 degrees to 48 degrees, however,
it can take over 10 hours for a 48 degree keg to cool down to 38 degrees.
Beer Temperature
Changes
There are several
reasons why a keg’s temperature increases.
One is poor refrigeration.
If the keg box, or walk in cooler refrigeration unit is malfunctioning, the
kegs stored inside will warm up over time.
If the door to
the box or cooler is left opened, or continuously opened and closed, the temperature
inside the unit will increase, and the keg will warm up resulting in foam.
Another reason
why the keg could be warm is related to when the keg was delivered. A keg of
beer that has been on a delivery truck for several hours going to be warmer
than 38 degrees F when it arrives at the retailers location.
A fourth reason
could be the venue at which the beer is served. If it is a picnic or special
event, chances are good that the keg has been left outside, and allowed to warm
up.
Preventing
Temperature Changes
To prevent foaming,
make sure that the refrigeration unit is properly maintained, and capable of
maintaining 38 degrees F. In addition, make certain that the unit is used only
for the storage of the beer kegs. Placing other items in the unit will lead
to people opening and closing the cooler door, and this will warm the cooler.
If other items must be stored in the cooler, you should mount heavy duty plastic
strips at the doorway to prevent cooling loss, or place a curtain of the strips
half way inside the cooler, and store the beer on the side furthest from the
doorway.
Uncontrollable
Temperature
If temperature
changes are uncontrollable, an effective way to prevent temperature fluctuations
from negatively impacting your kegs is to install a gas blender. A blender will
help to ensure that the proper amount of blended gas is being applied to the
keg at all times.
Keg
Deliveries
When a keg is
delivered to an account, it should be placed in the cooler immediately, and
allowed to cool down. A keg that has just been delivered to the retailer should
never be connected to the system until it has had time to cool to the proper
dispensing temperature.
Parties and
Special Events
If a keg is to
be dispensed at a special event or a picnic, try to place the keg in a cooling
tub with lots of ice, or at the very least place some bags of ice on the keg,
and wrap everything in an insulating blanket.
The Beer Temperature
Bottom Line
To improve the
bottom line, make certain the beer cooler is working correctly, that the glycol
system is operating properly, and get the beer pouring at 38 degrees F to maximize
the number of glasses served from each and every keg
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Three
Types of Draft Beer Dispensing Systems
Introduction
There
are three different types of beer dispensing systems commonly used in the United
States today. All three-system types have their own specific functions, components
and application depending on space and cost considerations.
Purpose
The purpose of
this section is to describe the basic functions and components of the three
types of draft beer dispensing systems.
Three
Beer Dispensing System Types
• Direct
Draw - The most common and simplest system is the Direct Draw system.
This system is
used when the keg of beer is located within a few feet of the beer dispensing
faucet.
The applied CO2
gauge pressure will be set at between 13 - 15 PSI (Pounds per Square Inch)
depending on the type of beer, storage temperature and elevation.
The beer tubing
will consist of approximately five feet of 3/16 ID vinyl beer tubing. This
will vary depending on the applied gauge pressure. (View the article titled,
“Balancing Direct Draw Beer Systems”.
Most commercial
keg boxes, home bars, and refrigerator conversions use this type of dispensing
system configuration.
• Air Cooled
System - The second dispensing system is the Air Cooled system.
This system utilizes
either a single or a double insulated air duct(s) with a large blower fan
circulating the air to maintain the beer temperature from keg to faucet.
This system is
only effective for systems less than 25 feet in length. If bends are required
in the ductwork the distance is reduced by 5 feet for every 90 degrees of
bent ductwork.
A large electric
fan, located in the cooler, near the source of the refrigerated air, circulates
cold air through the ducts, which house the beer tubing.
• Glycol
Cooled System The third type of system is the Glycol Cooled system.
The Glycol Cooled
system utilizes a glycol cooler to recirculate Propylene Glycol through polyethylene
tubing, which is wrapped to be in constant contact with the beer tubing. All
these tubes are encased within an insulated housing, called a Trunk Line.
The glycol maintains
the beer’s temperature from the walk-in cooler to the beer dispensing
faucets.
Correct carbonation
levels are obtained by using a blend of CO 2 gas and Nitrogen gas. This blend
of gasses allows the applied pressure to be increased to propel the beer the
required distance without over carbonating the beer.
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Draft
Beer System Maintenance
Overview
Introduction |
Whether
you own a direct draw, air –cooled, or glycol-cooled system, you
need to maintain the system with some basic practices. |
Purpose
|
The purpose
of this document is to present the basic guidelines, and time tested practices
to keep your beer dispensing equipment working properly and serving beer
that tastes great. |
Four Guidelines of Beer Dispensing
4 Guidelines
|
There
are Four basic guidelines to consider when maintaining any beer dispensing
system:
- Maintain
a consistent beer temperature of 38 degrees F.
- Set
the Applied Pressure according to the beer’s carbonation level,
temperature, and serving altitude.
- Build
in the restriction to balance with the applied pressure, and to maintain
a constant flow rate.
- Clean
the system a minimum of every 14 days.
! To ensure a beer system is functioning properly,
follow these guidelines. A quality product is the result of a well-maintained
system.
|
Maintenance
by Beer System Type
Direct
Draw |
Direct
Draw System – Self contained keg beer storage and dispensing system
- Maintain
a consistent beer temperature of 38 degrees F.
- Set
the Applied Pressure according to the beer’s carbonation level,
temperature, and serving altitude. At sea level this is usually 12-15
PSI
- Build
in the restriction to balance with the applied pressure, and to maintain
a constant flow rate.
|
Air
Cooled System |
Air
Cooled System (Walk in cooler system) - Not recommended for runs over
25 feet.
- Maintain
a consistent beer temperature of 38 degrees F.
Keep
the walk in cooler door closed at all times. If the door needs
to be open, use clear plastic curtains to prevent cold air from
being lost when door is open.
- Whether
using straight CO2 or a gas blender (CO 2 & Nitrogen) assure the
system restriction is balanced properly to the applied pressure.
Use
20-25 PSI as a target applied pressure for blended gas
- Each
beer line should have its own secondary regulator to set the applied
pressure.
- Check
for proper air-flow circulation from the walk in cooler to the dispense
towers and back.
Impeller
blower must be sized properly for good air circulation.
It
is not recommended to have more than two - 90 degree bends.
- Line
cleaning performed on a regular 14 day interval
Procedure
should include:
A sodium
hydroxide (caustic) based solution for ongoing regular cleaning.
An
acid based cleaner is recommended every third or fourth cleaning.
In-place & portable pressurized cleaning equipment can be used
but a motorized cleaning pump is recommended for more effective
cleaning.
Disassembling
and cleaning the keg coupler and faucet.
Rinsing
the system thoroughly with water.
|
Glycol
Cooled System |
- Maintain
a consistent beer temperature of 38 degrees F.
Keep
the walk in cooler door closed at all times. If the door needs
to be open use clear plastic curtains to prevent cold air from
being lost when door is open.
- Use
a gas blender (CO 2 & Nitrogen), and assure the system restriction
is balanced properly to the target applied pressure.
Use
20-25 PSI as a target applied pressure for blended gas.
Each
beer line should have its own secondary regulator to set the applied
pressure.
- Use
a quality trunk housing or python containing barrier beer lines.
- Properly
size the glycol power pack to the system length, and locate it in
a well-ventilated area. Never place the glycol cooler inside the walk
in cooler.
- Have
the glycol power pack serviced and the glycol replaced every year.
|
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Foam
on Beer Detectors
Introduction |
FOBs installed in a long draw draft beer system will reduce beer waste and
increase beer profits. |
Purpose
|
The purpose of this article is to describe how an FOB works , and to explain
how using an FOB(s) can increase profits from draft beer sales when installed
on a long draw beer dispensing system. |
Facts about FOBs
Beer
Waste is Reduced |
When
an FOB is installed on a long draw beer line and the keg empties, the
beer flow is stopped immediately. The beer line remains full of beer,
instead of filling with foam.
Keeping the
lines full of beer eliminates the need to refill the lines and purge the
system with beer when tapping the next keg. This will significantly reduce
beer waste. The actual reduction is based on the length of draw of the
beer system being considered.
The chart
below illustrates the reduction in beer waste when a FOB is installed.
Kegs per Week |
12oz
Glasses of Beer Wasted per Week |
20 |
46 |
70 |
93 |
117 |
15 |
35 |
52 |
70 |
87 |
10 |
23 |
35 |
46 |
58 |
5 |
11 |
17 |
23 |
29 |
|
100’ |
150’ |
200’ |
250’ |
Feet of Beer Line |
! Multiply the glasses wasted per week by the profit per glass, to calculate
the money that could be gained with an FOB(s).
|
Stop
Pouring Profit down the Drain |
For
example: (Use the chart above to calculate the result)
An establishment
without FOBs installed dispenses 20 kegs per week, through a system that
has a 100-foot beer draw. The beer needed to purge and refill the lines
would equal approximately 46 12 oz. glasses. Multiply the number of glasses
by the profit per glass. Lets say at $1.00 per glass, this would equal
$46.00 dollars per week wasted. As you can see from the example; FOBs
installed in a long draw system will reduce your waste and increase your
profits.
An FOB will
pay for itself in only 6 kegs.
Make the
investment and install FOBs in your long draw beer system.
Stop pouring
profits down the drain. |
How FOBs Work
Beer
Flow Operates the FOB |
Beer
flowing from the keg forces the float inside of the FOB into the up position,
allowing beer to flow to the faucet.
When a keg
empties, the float drops down stopping the beer flow from the keg.
Tap a new keg
and reset your FOB. Pushing the vent mechanism allows the gas/foam to release
from the chamber. This function allows beer to flow from the keg into the
chamber, lifting the float and allowing beer to flow to the faucet. |
Maintenance of FOBs
More
FOB Facts |
FOBs
must also be maintained and cleaned on a regular bases the same way beer
lines are cleaned.
How do the
FOBs get cleaned?
The FOBs
are equipped with a float-lifting device. This device lifts the float
off the beer outlet hole, allowing flow of cleaning fluids to enter and
exit the FOB detector and travel to the faucet.
Under no
circumstances should the FOBs be bypassed during the cleaning process.
!
Failure to clean the FOBs on a regular schedule will result in contaminated
beer to the customer. |
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Dispensing
Beer With Blended Gas
Blended
Gas Overview
During the past
decade or so, utilizing a mixture of Carbon Dioxide (CO2) and Nitrogen (N) gasses
for dispensing draft beer has become enormously popular at retail outlets such
as bars, restaurants, pubs and major venues. Driving this popularity is the
dispensing of stout or nitrogenated draft beers. Guinness, Murphy Stout, Boddington
and other craft brews require a CO2 and Nitrogen blend to achieve the correct
presentation, and flavor in the glass.
Gas blending is
also applied for dispensing ales and lagers where high gas pressures are required
to propel beer through a draft beer system. Today, blended gas technology is
capable of supplying the appropriate ratios of mixed gas to both stout beer
and ales/lagers while protecting the integrity of the product from keg to glass.
CO2 &
Draft Beer
Carbon dioxide
is natural to the brewing process and is considered an ingredient of the brewer’s
recipe. CO2 has flavor characteristics and must be maintained with the gas pressure
source, or the product will either become flat or gassy. The CO2 content in
beer is measured in volumes. Temperature, applied gauge pressure (Pounds Square
Inch Gauge – “PSIG”) and the gas blend ratio influence the
CO2 content. If the CO2 partial pressure in the mix is too low, this allows
CO2 to leave the beer and enter the keg’s headspace resulting in flat
beer. If it is too high in the mix, CO2 is imparted in the top surface layer
where the beer and gas headspace meet, saturating the beer. This layer of gas-saturated
beer will eventually be at the bottom of the keg and it will be like trying
to dispense a beer mousse – all foam. These conditions are undesirable
for pour cost or resale at a retail establishment. The key is to apply the correct
CO2 partial pressure to maintain equilibrium in the keg, so the CO2 in the beer
does not leave solution nor is there gas being imparted into the beer.
Nitrogen
& Draft Beer
Nitrogen has the
symbol N and is a colorless, odorless, tasteless and mostly inert non-metal
gas. It is readily obtainable, as it constitutes 78% of the Earth’s atmosphere.
It has a wide variety of applications, including serving as a more inert replacement
for air where oxidation is undesirable – beer. Perfect for mixing with
CO2 and supplying the extra hydraulic push required during dispensing. A further
example of its versatility is its use in nitrogenating some beers, particularly
stouts, which make the dispensed beer smoother and headier.
Why Blend
Gasses?
Different beers
require different gas blends to maintain the brewers favor characteristics.
A nitrogenated beer will typically have a lower CO2 content (volume) and thus
demands a lower CO2 partial pressure. However, the beer must still be propelled
through a draft beer system. This requires an applied gas pressure (PSIG) much
higher than the CO2 partial pressure. The difference in pressures is made up
with a ratio of Nitrogen. Nitrogen is the Brewers choice because it is also
a key ingredient used to achieve the thick and tight knit foam characteristics
associated with Nitrogenous beers on tap. A higher applied pressure is also
required for dispensing stout beers through stout faucets to acquire the cascading
effect and creamy froth in the glass. Applying the right blend of Nitrogen and
CO2 for the applied pressure required by the beer system will assure a high
quality, great tasting beer.
Nitrogen is also
blended with CO2 to propel traditional Lagers and Ales through a draft beer
system. Lagers and Ales do not contain Nitrogen, so the Nitrogen is only used
to compensate for the difference between the beer systems required applied pressure
(propelling pressure) and the CO2 partial pressure needed to maintain the flavor
and quality of the beer on tap. Typically beer systems greater than 25’
in length and or those with chronic temperature fluctuations will require the
higher applied pressures.
The Right
Gas Blend
The gas blend
ratio is based on the CO2 volumes of the product, temperature of the beer and
required pressure to the keg. CO2 Volumes for stout beers such as a Guinness
range from 1.2 volumes to craft stouts with up to 1.7 volumes. Ales and lagers
can range from 2.2 up to 2.8 volumes and in some cases, higher. An ideal liquid
temperature is 38° F. A survey of American consumers finds this to be very
desirable temperature for consumption and the CO2 in solution is very stable.
The “PSIG” at the keg using mix gas normally range from 20 to 25
PSIG for ales and lagers to 30-40 PSIG for stouts. To acquire equilibrium with
stouts a 25% CO 2 / 75% nitrogen mix is ideal and for ales and lagers a 60%
CO 2 / 40% nitrogen ratio.
Blended
Gas vs. Pre-Mixed Gas (Cylinders)
Mixed gas from
cylinders and on-site gas blending are the two sources of this medium for dispensing
draft beer. Mixed gas in a gas cylinder is normally a mix of CO2 (25%) and N
(75%) and available through existing gas suppliers. It is commonly called “beer
gas” or “Guinness gas”.
Mixed gas in a
cylinder with a ratio of 25% CO2 / 75% N is appropriate for stout beers but
when applied to ales and lagers, allows the beer to go flat because the partial
pressure of CO2 is too low. Gas suppliers have difficulties raising the ratio
of CO 2 in the mix as this gas eventually liquefies under high pressure in the
cylinder. This mix in a cylinder is expensive, and the ratios of CO 2 and Nitrogen
can be very inconsistent and the amount of gas contained in the cylinder is
low. The internal pressure of mixed gas cylinders is also considerably higher
than a cylinder containing only CO2, thus increasing the potential risk of an
accident.
Unfortunately,
many retail outlets are improperly applying mixed gas in a cylinder to their
beers on tap. These retail establishments are attempting to offset system inefficiencies
(temperature fluctuations) with higher applied gas pressures and the wrong gas
blend ratios, thus affecting the beer’s flavor, quality and sales. This
is a costly mistake because draft beer is so profitable, the last thing a bar
owner should do is serve off-taste draft beer and cause their customers to switch
to a bottle, can or worse yet, go somewhere else to drink a pint.
On-site blending
entails a source of CO2 such as bulk or cylinder gas and a nitrogen cylinder
or nitrogen generator. These two gas sources are supplied to a very accurate
blending device. The blend can be customized to deliver the right CO 2 Nitrogen
blend for the beer(s) on tap. Blending gasses on-site is the preferred method
of supplying a gas blend ratio to draft beers.
From
Keg to Glass
The objective
of dispensing draft beer is to serve the freshest best tasting beer possible
while reducing a retailer’s pour cost. Serving a great tasting beer will
assure retailers optimum profit from the investment they make in their keg beers.
In the best interest of breweries and beer wholesalers, being successful at
serving great beer will maintain a brands image while supporting their sales
efforts with bottle and can packages.
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Balancing
a Direct Draw Draft Beer System
Overview
Introduction
|
A
Direct Draw Beer Dispensing System is a self contained, thermostatically
controlled refrigeration unit, in which one or more kegs of beer
are stored at an optimum temperature of 38 ° F. This system
is equipped with beer dispensing hardware and 3/16” inside
diameter (I.D.) beer line that can be used exclusively between
the keg coupler and faucet.
A
Direct Draw Beer System may be contained within a walk-in cooler,
a commercial keg box, or within a kegerator or converted refrigerator.
These units are available for purchase commercially and for home
use. The information that follows will describe the process and
procedures to successfully balance any Direct Draw Beer System. |
Purpose |
The
purpose of this document is to define what a balanced beer system
is, and introduce the reader to the components that make up a
direct draw draft beer system. Additionally, this document will
explain the procedure and illustrate the calculations required
to properly balance this type of beer system. |
What
is a Balanced System
Three
Objectives of a Balanced System |
Balancing
a Direct Draw Draft Beer System involves calculations and measurements
to meet three main objectives:
- Protecting
the integrity of the beer
- Eliminating
waste
- Acquiring
an industry standard flow rate of approximately 128 ounces per
minute or approximately 1 gallon a minute.
Success
in meeting these objectives depends on balancing two separate
pressures:
- Applied
gauge pressure
- Restriction
pressure.
!
System balance does not have to entail calculations reserved for
rocket science. Acquiring accurate measurements and using simple
math will be sufficient. |
Balancing
Two Pressures
Balancing
Gauge and Restriction Pressure |
There
are two distinct pressures in a draft beer system.
- Gauge
Pressure, is the actual pounds per square inch gauge (PSIG)
pressure of 100% CO 2 applied to the keg. This propels (pushes)
the beer through the system. The volumes of CO 2 in the beer
and its temperature determine PSIG. A domestic lager with 2.6
CO 2 volumes at 38° F requires 14 PSIG @ sea level to maintain
product CO 2 levels while eliminating foam issues.
- Restriction
is defined as the pounds per square inch pressure (PSI) of resistance
the beer encounters as it flows through the system. This Restriction
comes from three sources:
- System
Hardware
- Gravity
- Beer
tubing
Each
variable has a known PSI value and is measurable. When identified
and accumulated, this total restriction value works to oppose
the gauge pressure.
When
these two pressures are equal, a flow rate of approximately 128
ounces per minute is acquired, creating a balanced system.
An
example would be a draft beer system that requires 14 PSIG applied
pressure to the keg with restriction consisting of hardware, beer
tubing and gravity that amount to 14 PSI. The beer is pushed through
the system with the same amount of resistance it encounters along
the way resulting in approximately 128 oz. / min. |
Restriction
Sources
System
Hardware |
The
hardware components in a draft beer system consist of tailpieces,
unions, faucets, shanks, couplers, and more. All of these components
restrict the beer as it passes through. Most pieces impart so
little restriction that they can be ignored.
One
piece of hardware that cannot be ignored is a shank and tube assembly
that is utilized in the towers of some Kegerators. It consists
of ¼” outside diameter stainless tubing with threads
on one end that protrudes down the tower into the refrigerated
box itself. The beer line with fittings is easily attached to
these threads. When this shank is present, beer encounters 3 PSI
of restriction and must be included in the restriction calculations. |
Gravity |
Gravity
is referred to as either vertical lift or drop. The faucet is
either above or below the bottom of the keg.
The
easiest method of measuring is to visualize two horizontal planes
in the system, one at the faucet and the other at the bottom of
the keg, then the vertical distance between them. This vertical
distance is measured in feet and has a PSI value of .45 per foot.
This is rounded to .5 PSI for ease of calculating.
A
typical direct draw system has a vertical lift distance between
these two planes of approximately four feet thus 2 PSI of restriction
in gravity. (4 X .5 = 2) |
Beer
Tubing |
Since
it is easily cut to length, beer tubing is the restriction component
utilized to balance the system after hardware and gravity are
determined.
Vinyl
beer tubing with a 3/16” inside diameter (I.D.) has 3 PSI
of restriction per foot and is used exclusively in direct draw
systems.
Note
- Kegs positioned in a walk-in cooler where the calculated length
of 3/16” beer tubing will not be long enough to reach between
the coupler and faucet is considered a remote system, and more
advanced balance principles apply. |
Practice
Balancing a Direct Draw System
Establish
the Applied Gauge Pressure |
The
first step to balancing a beer system is to establish the applied
gas pressure gauge (PSIG) of 100% CO 2 required to propel and
maintain the beers carbonation to the brewers’ specification.
This is based on the beer’s CO 2 volumes and the temperature
of the beer.
! Refer to the brewer’s specifications for specific CO 2 volumes.
Note
– Correct for altitude by adding one pound of PSI gauge
pressure for every 2000’ above sea level. |
Identify
the Restriction Sources |
For
example - a 2.6 volume beer at 38° F requires 14 PSIG to
maintain the product’s carbonation, and eliminate any foam
issues.
This
system has 4’ of vertical lift and no shank with tube assembly.
To
balance this system to 128 oz. / min. flow rate, the applied pressure
must be balanced with 14 PSI of hardware, gravity and beer line
restriction.
| CO2
Volume |
2.5
Volumes |
|
| Beer
Storage Temperature |
38 °
F |
|
| |
|
|
| Calculations:
|
|
|
| |
|
|
| Gauge
Pressure |
|
14
PSI |
| Hardware
|
Shank
with Tube N/A |
-
0 |
| Gravity
|
4’
x .5 |
-
2 |
| Restriction
to be made up with vinyl beer tubing |
12PSI
|
| |
|
| Beer
Tubing Length |
12/3
= 4’ of 3/16”ID vinyl beer tubing |
|
Calculate
the Length of Beer Tubing |
The
example above requires 12 PSI of restriction to be made from a
length of 3/16” vinyl tubing. To calculate the length of
line needed simply divide the restriction required (12 PSI) by
the pounds of restriction per foot of tubing (3 lbs/foot)
12
/ 3 = 4 feet of 3/16 ID vinyl beer tubing. |
Example
2 |
System
Specifications
| CO2
Volume |
2.8
Volumes |
|
| Beer
Storage Temperature |
38 °
F |
|
| |
|
|
| Calculations:
|
|
|
| |
|
|
| Gauge
Pressure |
|
16
PSI |
| Hardware
|
Shank
with Tube |
-
3 |
| Gravity
|
4’
x .5 |
-
2 |
| Restriction
to be made up with vinyl beer tubing |
11PSI
|
| |
|
| Beer
Tubing Length |
11/3
= 3’ 8” of 3/16” ID vinyl beer tubing |
| !
4 inches of 3/16 ID tubing has 1 PSI of restriction |
|
Beer
Temperature and CO 2 Content
Determining
PSIG to the Keg |
Beer
temperature and CO 2 volumes determine ideal gauge pressure, (PSIG)
to the keg.
!Gauge
pressure should never be adjusted to control the beer flow rate.
Balancing
a system correctly eliminates unnecessary regulator adjustment,
and helps guard against other problems associated with Direct
Draw Beer Systems. Balancing a System results in a manageable
flow rate, and maintains a product’s integrity. Waste is
reduced, profits are increased and beer is enjoyed as the brewer
intended. |
|
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Presenting
Draft Beer to the Customer
| 
