Beyond the Bar
As soon as beer finishes fermentation, it begins to decline. The twin evils of time and temperature take a toll and sooner or later, every beer will taste noticeably different from that “just fermented” flavor. Let’s look at how these issues influence the flavor of draft.
Before craft beer came along, draft beer had a reputation as being beer at its best. The reasons for this are tied up in two issues: pasteurization (or lack thereof) and cold storage throughout the entire distribution chain.
Most breweries ship unpasteurized draft beer. This prevents the slight flavor loss that occurs during pasteurization, but leaves the beer susceptible to microbial infection. To preserve what brewers call the “biological stability” of draft beer, it must be kept refrigerated, so U.S. distribution channels have long been set up to keep beer cold from brewery to bar cooler.
If you visit a U.S. beer distributor, you’ll find a large warehouse that’s maintained at room temperature. Most bottled beer gets stored here to await shipment to a retailer.
Draft beer is a different matter. That gets stored in a nice cold walk-in refrigerator at about 40 degrees F. And, because refrigerated warehouse space is more costly, distributors keep it to a minimum and therefore move the refrigerated inventory more rapidly. That means that in addition to being unpasteurized and maintained cold, draft beer spends less time in transit from brewery to bar and is probably fresher in addition to being better kept.
Among craft brewers, pasteurization is unusual. But larger brewers commonly pasteurize bottled beers. Thus, prior to the craft beer revolution, draft beer had a reputation for being better than bottled product. Today, small and artisanal brewers rarely use pasteurization so bottle and draft leave the brewery at flavor parity. Still, the differences in distribution temperature and turnover persist, so draft may still be the fresher product in most cases.
At the Brewery
We’ve seen how various influences beyond the brewery can ruin the flavor of beer. Of course the brewery itself plays a key role in preparing kegs so that they taste great when they arrive at the bar.
Perhaps the most important part of kegging comes in cleaning returned kegs. Since you can’t see inside them, they must be subjected to an intense sequence of steps that includes caustic cleaners and near-boiling water as well as the occasional acid rinse before a final cold-water flush.
Oxygen is bad for beer so anytime beer gets moved or filled brewers try to minimize exposure to air. Kegs offer a nearly ideal container for oxygen-free fills as they can be purged with CO2 in advance. Furthermore, filled kegs are nearly impermeable to air so oxygen doesn’t seep in during transport and storage.
At most breweries, the cleaning and filling processes are automated to ensure the proper sequence of steps and consistent high-quality results. And of course, brewers know the importance of keeping draft beer cold, so you’ll find filled kegs stored in a refrigerated section of the warehouse until they are shipped to the distributor.
So that’s a look at the key issues affecting draft beer quality. It takes a team effort to put great tasting draft beer in your glass. If any one of the players involved drops the ball, the resulting product can be less than wonderful or even exceedingly bad! As a consumer, pay attention to the quality of the beer you receive and make it a point to patronize places that get it right.
The Brewers Association has an excellent guide to draft beer quality that you can read or download at www.draughtquality.org. This is a highly recommended resource for people in the trade.
Those who want to know more about the presentation of quality beer might consider participation in the Cicerone Certification Program. For more information, see www.cicerone.org.