Proper Beer Handling: From Fermentor to Glass04/12/2013
From Fermentor to Glass:
Handling, Dispensing, and Serving Beer
Originally Published in Brewing Techniques Volume 7, Issue 2 by Mikoli Weaver
What happens to your beer between the fermentor and the glass can make or break your reputation as a brewer. Bottling brewers have their own set of problems, but pub brewers carry the additional burden of being concerned about how people serve their beer.
Good brewers know the importance of caring for their beer through all stages of the brewing process. After all, a high-quality product is made such by the way it is handled from formulation to packaging. We devote ourselves to perfecting the details — tweaking the recipe, searching out the best ingredients, watching temperatures and chemistry, and meticulously cleaning. But the beer spends only part of its life in the brewhouse. Transportation, storage, and serving of the beer influence the quality of the customer’s pint as much as formulation and brewing do.
Whether your beer is served in your pub or by an off -premise account, you, the brewer, must make sure your beer is being treated properly after it leaves your tanks. Proper handling, dispense equipment, and service will help to ensure that your customers are receiving the best beer possible. This article describes some ways that brewers, pub managers, and service staff can maintain the quality of beer after it has left the brewhouse. It is not meant to be a primer on beer handling, but rather is intended to serve as a reminder of principles that sometimes get forgotten as we wax on about the latest yeast strain or hop variety.
Handling — Rules of Thumb
Correctly moving and handling draft beer in the pub can save hours of problems and costly waste. Serving tanks will greatly improve the quality of your life, but if you have to deal with kegs on- or off-premise, a few simple rules of thumb will help you avoid problems down the road.
Let sleeping yeast lie: Even if your beer is filtered, you want to keep your kegs as still as possible. Try to avoid agitating or shaking the keg. Excess foam will be discarded at the expense of many hop components that contribute to the aroma and flavor profile of the beer, as well as compounds responsible for head formation and retention. Another possibility is that some of the foam could also stick to the inside of a half-empty keg like lacework in a glass and never return to the beer, with the same net result.
Then, of course, there’s the beer loss. Anyone who’s ever winced at a server scooping precious foam off a pint of beer knows the importance of maintaining proper carbonation. Even though it is sometimes the practice to disturb the yeast inside of some kegs of unfiltered wheat beer, this is an exception, not a rule. And even in this case, the beer must still be left to settle down before serving.
The pressure is on: Make sure that you do not add carbonation to your kegs in the course of dispensing the beer. Determining the proper dispense pressure can be a tricky prospect and is an article in itself. The pressure used to push the beer needs to be sufficient to move the beer to the faucet without increasing the level of carbonation. Many factors come into play when determining how much to add to compensate for pressure losses in the lines. About 0.5 psi is lost per vertical foot, for example. Typically, about 0.5 psi pressure needs to remain at the faucet for the beer to flow. Using a mixed-gas blend is a great way to boost the dispense pressure without adding the taste sensations of carbonation because nitrogen is slow to dissolve in solution and does not add carbonic acid to the beer.
Over- or underpressurization of a keg can be remedied, but such quick fixes should not be considered a substitute for proper carbonation practice in the brewhouse because it is far less efficient.
Watch the thermometer: CO2 absorption changes with temperature, so keep the beer at a constant temperature when it is on tap, and as close to the carbonating temperature as possible. For many styles, 2.5–2.6 volumes is an appropriate amount of dissolved CO2, which is equal to 15–16 psi at 45 °F (7 °C) — a good place to set your draft beer dispense pressure. Lower temperatures create more carbonation, whereas higher temperatures force more CO2 out of solution and increase the pressure, which will be vented at the regulator.
Don’t forget that storage temperature will also directly affect flavor. Some customers may think that beer is best when it’s ice cold (“How about a frosty one?”), but temperatures below 40 °F (4 °C) actually inhibit the beer’s aroma and flavor. Colder beer decreases our ability to taste and smell, partly because the cold inhibits the sensitivity of our tongue, and partly because many flavor and aroma compounds remain in the beer better at colder temperatures — which relates back to carbonation. The carbon dioxide is better dissolved at colder temperatures and so does not drive volatile flavor and aroma compounds out of the beer as fast. As the beer warms we begin to become more sensitive to its flavors. Of course, the flavors that come out may not always be pleasant, so a beer that is served too warm can appear to be damaged. Many brewpubs compromise with serving temperatures of 42–45 °F (6–7 °C), which is cold enough to keep the drinking experience refreshing for all styles, but quickly warms a few degrees for optimum flavor and enjoyment.
Draft Dispense Equipment
Most dispense equipment and systems are pretty standard, but because they are often installed by nonprofessionals the systems may have flaws that will inevitably lead to lost product and possibly lost customers.
Lines: Beer. Beer lines need to be designed for smooth, consistent flow. Choose a standard clear vinyl line with an inside diameter (i.d.) sufficient to provide the resistance necessary to keep the gas in solution and thus reduce the tendency to foam.
Avoid up-and-down runs in the beer line. CO2 comes out of solution and rises to the high spots in the line, causing foaming. Sometimes removing the coupler during a keg change also causes foam to accumulate in the high spots. If the kegs are in the basement and the lines are straight up, there is not much you can do, but if the grade can be eased when the lines are installed, it will reduce foaming problems. Kinks and pinches in the line can also restrict the flow of the beer, leading to foaming or, at worst, no beer getting through. (I’ve seen kegs resting on lines, cutting off all beer supply.)
Some pubs have to have very long beer lines — I’ve seen some of 100 ft or more — which can cause several problems. For one thing, long runs require more pressure; some houses have to run as much as 40 psi to push the beer the distance to the faucet. After a while the excess pressure will overcarbonate the beer in the keg. Very long lines may require an in-line beer pump to push the beer through them; using a mixed-gas blend of nitrogen and CO2 can allow the beer to be pushed at a higher pressure without overcarbonating. (See “Some Dispense Alternatives” section on page 52.) Serving tanks, of course, typically can handle only 15 psi and thus need to be pumped, so the mixed gas won’t help. Fine-tuning of the dispense system often happens at the faucet by adjusting the length of the choker hose. Your draft technician or beer supplier should be able to offer more advice about balancing your system.
Another problem with long lines is in keeping temperature constant. To maintain the temperature of the beer in the lines, they can be bundled with a refrigerated glycol line and insulated. Glycol can be run through normal beer lines, but it is safer to use a lined hose with a braided coating to prevent leaks, although this type of hose does not transfer heat as effectively as beer line does.
A third problem with long lines is the amount of beer that they hold — three pints in a 100-ft line. This beer must be wasted when they are cleaned, which tempts pubs to put off cleaning them. But the effects of dirty lines can be very noticeable when bacteria and wild yeasts impart their unpleasant flavors to the beer. The clear lines will reveal any crud inside; regular maintenance (see “Cleaning dispense systems” section on page 52) will eliminate the need for replacement, which can cost as much as $ 0.50 a foot.
Because plastic absorbs flavors, lines used for fruit beers, wine, and especially root beer should be used only for those products to avoid contaminating other beers with their flavors. And because it is also possible for root beer flavor to travel across lines, lines with special nonporous linings should be used, or, even better, the lines should be run on a separate trunk.
Gas. Gas lines are typically of the same food-grade plastic, colored red or blue and sized from 5/16-in. i.d. (The inside diameter of gas lines is not important, but you do have to choose a size that fits your equipment.)
Standards and faucets: Beer standards (towers) are pretty much all alike. They must be well insulated to ensure that no warm spots surround the beer lines as they travel up to the faucets. Maintenance is limited to cleaning the surface and keeping the threaded connections sanitary during tap cleaning.
The faucets also are mostly all alike, with the exception of some that have flow control valves. They all come apart into three or four main parts: the body of the faucet, the open/shut valve, and the arm that connects from the tap handle to the open/shut valve. When it comes time to clean the faucets, they must be taken off the standard, taken apart, soaked in hot water or cleaner, and sanitized to prevent bacterial growth and decay. Make sure that the rubber gaskets are all intact to prevent leaking (leaks encourage unsanitary conditions).
Cleaning Lines and Faucets
Lines and taps should be cleaned at least once every two weeks. Just as with other brewery equipment, both organic and inorganic deposits may have accumulated. The cleaning regimen should therefore consist of a caustic solution run regularly, with acid solutions run periodically to combat beerstone. All solutions should be weak and run at lower-than-normal temperatures for a longer-than-normal period of time. (Harsh chemicals and high temperatures can shorten the lives of plastic beer lines.) The solution should be circulated through the system in reverse of the normal beer flow to provide the turbulence necessary for effective cleaning; this requires use of a pump. (Some brewers choose to mix cleaning solution in a keg and run through the system as usual, but whereas this allows use of CO2 to push the beer, it does not allow for the reverse flow, and the CO2 may even react adversely with the caustic.) Often two lines are run together in a loop for convenience; the flow of the cleaning solution can be reversed midway through the process to backflush both lines. Multiple faucets can be coupled together to make a big loop, but the flow rate of the pump may be compromised in the process. The faucet should also be dismantled and its components soaked when the lines are cleaned.
If you are having persistent problems at the faucet, you may wish to consider using a different gas blend (see “Some Dispense Alternatives” section, below), or consider an alternative faucet design. For example, one company, Stainless One (Derry, New Hampshire), makes a faucet that stays full of beer, which would discourage the growth of aerobic organisms. The company also claims that the faucet is designed to reduce foaming and that the stainless steel eliminates the off-flavors commonly found in brass faucets.
Kegs and couplers: The U.S. Sankey-type kegging system is quickly becoming the standard. The valve draws from a small recess in the bottom of the keg, so there is virtually no beer left in the keg. The couplers are very easy to connect, making cleaning and sanitation much easier. And, since the Sankey-type keg is so widely used, your beer kegs will be compatible with most systems outside of your pub, which can help with off-premise sales. To keep the couplers working well and your beer healthy, soak them in hot cleaning solution and rinse them when it comes time to clean the beer lines.
Cleaning dispense systems: Most professionals recommend that you clean your taps and lines at least once every two weeks, especially if you’re using kegs. Cleaning is a simple and quick procedure that will end up preserving the integrity of your draft beer in-house and outside. In fact, one brewery for which I worked offered a weekly tap-cleaning service free to its good draft accounts. (See the box for more information.)
Some Dispense Alternatives
As U.S. consumers and publicans become more sophisticated, alternatives to beer highly charged with carbon dioxide are becoming increasingly common. Nitrogen, for example, is becoming a common ingredient in beer conditioning and dispense, and cask-conditioned beer is also gaining in popularity. Understanding mixed-gas systems and cask setups will help you ensure that your beer is presented at its best.
Mixed gas: As mentioned previously, nitrogen can help increase dispense pressure without increasing carbonation because it is far less soluble in beer than catbon dioxide. Because of nitrogen’s contribution of smaller, more consistent bubbles, using a mixed-gas blend for dispense can also contribute to increased foam stability (but not foam quality, which still comes from the carbon dioxide and components of the beer itself, mainly proteins and hop compounds). The appropriate mixture and pressure depend on whether the beer was gassed with straight carbon dioxide or with a nitrogen mixture. Blends of 70% N2 to 30% CO2 are common; check with your supplier to determine what is right for your system.
CO2/N2 mixtures can be purchased in tanks, but bottled mixed gas can be unreliable in its composition. An expensive, but effective, alternative is to buy the nitrogen in bottles and mix it on-site with a system such as the Trumix (McDantim, Helena, Montana), which allows you to set the proportions of CO2 and N2 in the mixture.
To take advantage of the effect of the mixed gas on the beer’s presentation, you need a special type of faucet. These faucets work in the same way as normal faucets, but they have a special disk inside to force the nitrogen out of solution when the beer is poured. The disk is made of metal or plastic and usually has five tiny holes in it. This forces the gas out and creates the cascading effect and smooth creamy head that are expected from nitro beers. These faucets may be harder to get apart than conventional faucets; cleaning might be limited to simply soaking the entire faucet in the “open” position and rinsing it well.
To really affect the foam quality, you would need to actually condition the beer with nitrogen, a process which, because of nitrogen’s relative insolubility, can take quite a while. An alternative to conditioning in the keg or tank has recently been introduced to the United States. The device can introduce the desired blend, or straight nitrogen, into uncarbonated beer directly in-line from the keg or tank to the faucet by way of a highly efficient membrane transfer. The system allows pressures higher than blending units can match, which allows for a level of conditioning truly equivalent to a draft Guinness in Dublin. The device also allows for on-the-fly adjustment of the conditioning level. (Look for upcoming issues of BT for more on mixed gas dispense and nitrogenation.)
Beer engines and cask beer: Cask conditioning is a good way for brewers to show off their creations. A beer engine will cost about $ 300. It is simply an elaborate pump that draws the beer from a cask or keg without the need for gas pressure. The beer engine is a great addition to the bar, but it requires a certain amount of maintenance to provide good beer to the public.
Make sure that the holding chamber is cleaned at the beginning of the day and rinsed with hot water or beer-line cleaner at the end of every day. Otherwise beer will sit in the pump and chamber all night long, facilitating bacterial and wild yeast growth. Since cask beer is unfiltered and very active, bacteria and yeast quickly grow in it.
It is also a good idea to take the cap off of the engine’s faucet for cleaning daily to reduce clogging and infection. At a pub, I once ordered a pint of cask beer that arrived with bits of hardened, sticky beer in it. Dried beer had built up in the tip of the faucet and was forced out into my glass.
In addition to diligence in cleaning, the type of beer engine and the way the cask is set up will determine how long your cask beer stays fresh. BT has published several articles about serving cask beers in the traditional fashion with a tap and spile. But if you’re using kegs, you have two options for setting up the beer engine.
The easiest is the open-air setup, which is nothing more than a regular coupler with two lines. The first line to the beer engine comes from the “beer out” fitting as usual. The second line, connected to the “gas in” fitting, is simply left hanging. This creates an open system that allows the ambient air to enter the keg each time you draw the handle of the engine. In this setup, the beer runs a risk of infection; the oxygen will provide the means for bacteria to continue fermenting the beer until all of the remaining sugar is gone, and the beer will have a much greater tendency to oxidize. Connecting the open-air line to an activated carbon filter will reduce the risk of infection, but the beer will still oxidize over time. An open system is appropriate only if the beer will be consumed within three days or so.
The second setup, also common, is a breather apparatus that costs about $ 90. A cask breather replaces the amount of air taken from the cask with an equal volume of CO2. In other words, each draw from the hand pump takes beer and air from the cask and replaces it with CO2 to help preserve the beer. The pressure is very low, only about 0.25 psi, so the keg beer will not take on additional carbonation. A cask breather allows the publican to keep your cask beer for a longer period of time without spoilage. The only care a cask breather requires is that you set the pressure (or buy one preset) so that it correctly regulates the gas in. To imitate the action of a cask breather, it might also be possible to simply keep the keg on a low-pressure CO2 blanket; that is, not enough pressure to actually push the beer (a “pushing” pressure would result in a dripping faucet because the beer engine has no resistance to forward flow).
Even if your beer is impeccably stored, handled, and dispensed, it is still vulnerable to damage when it’s in the glass. The last step in the beer’s journey to the customer is the service, an area that brewers should make it their business to know about.
Glassware: The beer glass is more than just a functional vessel to hold the beer. It can also be a major factor in the sensory part of the beer-drinking experience. The shape of the glass affects how we perceive the aroma and flavor of the beer. For example, a tall, thin glass has a greater ability to focus the nose of a beer than a wide glass, which allows the aromas to escape more readily, and also changes the flavor, because our sense of smell influences our sense of taste. For this reason, many classic beer styles, Belgian beers in particular, have their own style of beer glass. Each shape accents particular components within the beer that the brewers feel are essential to the flavor. A Pilsener or a wheat beer certainly takes on different characteristics when it is served in the proper glass, and Scottish ales in a dimpled mug can show off their complex maltiness. Unfortunately, in the United States the main style of beer glass is the one-pint mixing glass. Although having a different style of glass for each of your beers may not be practical, it is something to consider for specialty or seasonal brews. Serving barleywine in an 8-oz brandy snifter, lambic in a fluted glass, or IPA in a nonic-bulge pint may add an element of uniqueness to your customers’ drinking experience and enhance the flavor of your prized beers even more.
The shape of the glass is not the only thing that will affect the taste of your beer. Like an overly chilled keg, a very cold glass will inhibit the sensory experience. A room-temperature glass is best for serving and drinking beers. Very cold or frosted glasses can cause foaming and in some cases will freeze part of the beer, causing problems with the carbonation and flavor. They are best reserved for Bud bars and lawnmower beers.
Cleaning glassware: Of the two ways to clean and sanitize glassware — the manual three-sink method and the automatic dishwasher — the automatic is preferable. Employees generally use too much soap and way too much bleach in the three-sink method, and the “wash, rinse, sanitize, air-dry” method is simply not as clean or effective overall. The box “Glass Washing Tips” above suggests ways to make sure that hand dishwashing is uniform and thorough. Automatic dishwashers are really the best choice for cleaning and sanitizing, if you have the space and the money to install one. They are fast (one-to-three-minute cycles are standard) as well as effective.
Glass Washing Tips
Some dishwashers sanitize with a chemical solution, and others with heat. Machines that sanitize with heat need to have a prewash temperature of 85–110 °F (29.5–43.5 °C) and a sanitizing cycle of 140–160 °F (60–71 °C). Those that use a chemical sanitization cycle should wash between 120 and 140 °F (49–60 °C).
If the operator must manually add dish detergent, variations in the amount will affect the sanitation and amount of residue left on the glasses. An automatic detergent feed eliminates this problem but costs more.
It is best to have a dishwasher solely dedicated to the bar. If there is just one dishwasher for the whole establishment, glasses too often come out of it with soap or chlorine all over them. A particularly busy dishwashing machine may also leave food particles on the glasses. And unless separate glasses are used for other beverages, particularly milk, the residues can be especially hard to remove. All this leads to poor head retention, off-flavors, and undesirable aromas. And please, don’t serve in hot glasses.
Server education: Problems with beer handling, dispense, and service come to the attention of the servers first. Servers should be educated not only to sell the beer but also to identify and correct serving problems that affect the beer’s quality. Good bartenders and servers will not be as astute as most brewers, but they should be able to tell if the beer is off in flavor or why the head retention is suddenly lacking. As a team, the entire staff can really be effective in preventing or fixing problems. Server education and training is a very important issue that is often overlooked. It will be the subject of a future article.
After the Brewin’
As you can see, what happens after your beer leaves the fermentor is very important to its quality. Your reputation is at stake, so you owe it to yourself to get involved. Examine your brewpub or your off-premise accounts, using this article as a starting point. Taste your own beers every day — all of them, not just your favorites. Communicate your needs clearly to the staff, and talk to customers. Address problems as they arise, quickly and decisively. Involve everyone on the service staff, down to the dishwasher and busser, because their efforts are essential to ensure that every pint is a good one.
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