Flat Beer: Beers delivered with too little carbonation rarely cause great offense. Indeed, some consumers won’t even notice a flat beer. Still, they support no head or foam and have a dull, lifeless character on the tongue. People will drink a beer with reduced carbonation, but they rarely follow through with another thanks to the subtle signals of poor beer quality. The consumer loses out on enjoyment and the retailer loses beer sales.
Flat beer is more common than you would think. And the problem doesn’t come from the brewery because retailers usually create flat beer with improper draft system management. Here’s why: Normally carbonated beers often get pressurized with the same gas used for nitro beers like Guinness. Because nitro beers have less than half the carbonation of regular beers, the two beers need entirely different blends of gas. (See sidebar: And You Thought They Were Just Bubbles.) When a retailer serves a normal beer on nitro beer gas, they won’t notice any difference at first. But soon physical realities set in—as the keg empties, carbonation leaves the beer. By the time the keg is half empty, the carbonation could well be half of what the brewery intended. Ultimately, the cause of flat beer is inadequate CO2 pressure applied to the keg.
Foaming Beer: Beers that foam leaving the faucet cost retailers money. For starters, foaming wastes a lot of beer as a lot of foam generally goes down the drain. When you dump a pint of “foam,” you lose a quarter pint of beer. Such losses undermine beer—and bar—profitability. Customers lose too. Beer that foams excessively while pouring has lost some of its carbonation and won’t be quite what the brewer intended.
Surprisingly, the biggest problem here usually comes from warm kegs. Most draft systems operate at 38 degrees F. Although few bars realize it, a half-barrel keg that warms up to just 48 degrees F during delivery won’t pour properly. This usually mystifies the bar largely because a 48 degree F keg feels pretty cold to the touch. Unless you realize how exacting the temperature spec is on draft beer, you’ll feel the keg and think, “That beer is cold enough to serve.”
In truth, it takes a full 24 hours in the beer cooler for a 48 degree F keg to reach proper serving temperature. Except in the dead of winter, that means nearly any keg delivered today can’t be served properly until tomorrow. And if a keg warms up to room temperature for some reason, it can take up to two days to chill.
Another problem comes when the entire keg cooler warms up. During the day, cooler doors sometimes get propped open for deliveries or kitchen access. Another source of warming might involve large deliveries of warm goods like bottled water or soda. If beer in the cooler warms up 5 or 6 degrees during the day, all of the beers in the cooler will foam until temperatures drop back into line—a process that can take up to 12 hours.
Beyond keg temperatures, some systems suffer when beer warms up on its trip to the faucet. Draft system designs include beer line chilling, but these may fall short when summer temperatures put more stress on the system or if the cooling system itself is turned off or malfunctioning. Long-draw draft systems—any system where the run from the cooler to the bar is more than 15 feet—rely on a small glycol refrigeration system that typically has two switches: one for the compressor and one for the pump. If one is off, the system can’t operate properly.
If properly chilled beer foams at the faucet, then maintenance may be to blame. Without proper cleaning, lines build up mineral deposits over time. Those deposits change draft system dynamics making it impossible to pour liquid beer at any temperature. Once this happens, lines will need to be rehabilitated with intensive—and regular—cleaning.
Sour/Infected Beer: Poor draft system maintenance affects beer flavor as well. Under the worst circumstances, beer from poorly maintained lines pours hazy, sour and spoiled. It will have a buttery or butterscotch flavor usually mixed with vinegar or—gasp!—slight vomit traits. You might find this when you order beer from a slow-moving draft line or arrive just after opening and get the first pint of the day. Draft lines that pour sour on the first pint or two will give less offensive beer after several pints. Still, “less offensive” is a long way from “good.”
Draft systems that aren’t well maintained negatively affect beer flavor. Most consumers wouldn’t send beer from dirty lines back for being obviously “off”—but they can still tell that the beer doesn’t taste quite right. Thus, they often decide to order a mixed drink or head to a different bar instead. Dirty draft lines hurt business and profits.
Sadly, many retailers still neglect line cleaning. Why? Line cleaning costs money—not only for the service itself, but in terms of beer lost from the lines at each cleaning. Furthermore, many states and communities do not required retailers to clean lines or, if they do, have no effective enforcement. Even in communities with line cleaning mandates and health department inspections of cleaning logs, lines can still get funky. After all, proper cleaning depends on the use of proper cleaning solution, proper circulation routines and sufficient time spent doing the circulation. Cost-cutting line cleaners shave corners and leave lines far from “clean.” Over time, the effect on the lines can be the same as not cleaning at all.
How can you tell if lines aren’t clean? From a consumer’s point of view, draft beer should taste good. No, actually draft beer should taste great. The flavors should be fresh and bright and basically be as good as beer can be. When a beer pours foamy it means it is going to be poorly carbonated. If beer tastes dull or lifeless—especially when compared to the same beer fresh from a bottle, there’s a problem. You’ll have to rely on experience to spot a lifeless beer. Ask yourself if it tastes like it does when it comes from a bottle. Are you missing certain flavor notes? Or have those flavor notes changed? Lobby for proper cleaning or drink somewhere else.
Sadly, in some communities draft system neglect is common. When I asked a group of retailers and wholesalers in a large city I visited last year who did the line cleaning in that area, I got a room full of blank stares. If no one knows who’s cleaning the lines, it probably isn’t being done. That’s not a good sign for your beer.
Neglect can inflict other maladies on draft systems as well, although the ones we’ve discussed above are the most common. On the “really bad” end of things, a small number of bars still dispense beer with compressed air rather than CO2. This approach basically ruins every keg within a few hours of tapping. Another one that I have found is metallic flavors from systems so old that the chrome has worn off of the faucet interiors exposing the beer to brass. You won’t see these often, but when you do, they are reason enough to leave and never come back.