|Beer is Food
David B. Pastore
Beer is food. As with most foods, beer is perishable-it deteriorates as a
result of the action of bacteria, light, and air. To combat this breweries, prior
to bottling, make the beer undergo some form of stabilization to extend its
shelf life. The two primary forms of stabilization are sterile filtration, in which
the beer is passed through a microporous filter that will not let through any
"crunchy bits" larger than 0.5 microns; and pasteurization, whereby the beer is
heated briefly to kill any microbial wildlife.
The length of time it takes for a beer to become stale (a papery note, dulled
hop character, or other off flavors) is determined by the alcoholic strength and
hopping level of the beer. Both alcohol and hops help preserve beer. Thus
hoppier, stronger beers keep for longer. Typically, the freshness period for a
lager is four months; for stronger craft-brewed ales, five months. High-gravity,
high-strength beers such as doppelbocks typically carry a six- to twelve-month
freshness period. All of the preceding assumes proper handling of the beer.
Imported beer can have a rough ride on its way to your local retailer. First, it
must undergo a sea voyage, hopefully in temperature-controlled containers, or
"reefers," in industry parlance. After sitting in the bonded customs warehouse
(hopefully, air conditioned), it must pass through an importer’s warehouse and
then be shipped to a wholesaler’s warehouse. In the best case, the local
wholesaler will have temperature-controlled storage and an efficient stock
control system, although this is an area of commerce that is not renowned for
sympathetic handling of product or startling efficiency with stock.
One thing is for sure-at any moment of time in the Byzantine system of beer
distribution in the United States, a prodigious amount of imported beer is
sitting in warehouses slowly undergoing the inexorable effects of aging.
It must be said that some imported beers do carry a freshness date, but they
are vastly outnumbered by those that do not. Thus a consumer purchasing a
six pack of imported Czech pilsner or English bitter may have no idea as to
how long the product has been in the chain of distribution. In both examples
freshness is as important as with any domestic ale or lager.
Daylight can have undesirable effects on a beer over a period of time. The
ultraviolet portion of the spectrum is especially harmful; promoting chemical
reactions that produce "off flavors" that will take the edge off the freshness of a
beer. Dark glass greatly inhibits this photochemical effect, whereas clear
glass leaves the beer within vulnerable to being "light struck." The industry
standard is for green or amber glass, but for marketing reasons a number of
breweries stick resolutely to their traditional practice of using clear glass
bottles, with often undesirable consequences when such beers are left on a
retailer’s shelf for any length of time.
Cans,of course, are the best protection against harmful light. Although cans do
not fit the image of the craft-brewed product, there is no technical reason why
high-quality beer cannot be sold in cans. However, a significant impediment
to craft brewers using cans instead of bottles is the high capital cost of the
pasteurization and packing equipment required.
And don't be fooled by a brewpub that sells you a growler and tells you it will
remain fresh for a week. Beer sold in this format must be refrigerated and
then consumed within one to three days no matter how the growler is sealed.
Beers that have been bottled unpasteurized and unfiltered, with a significant
amount of live yeast, are called "bottle-conditioned" beers. The purpose of
bottling beers in such a manner is to give them the potential to age and
develop more complexity. Yeast inhibits oxidation and contributes complex
flavors as it breaks down slowly in the bottle. Many Belgian ales are
traditionally bottle conditioned through a secondary fermentation in the bottle,
in a process similar to that which produces champagne.
Bottle conditioning is an economical means for small-scale craft brewers to
bottle ales without the need for costly pasteurization or filtration equipment.
How long one cellars bottle-conditioned beers is a matter of personal taste
and will also depend on the specific character of the beer in question.
Fresh, well-brewed beer that has traveled only a small number of miles will
invariably taste better than an equivalent beer that left the brewery a few
months ago. Indeed, a draft beer that has traveled a great distance will
certainly have been pasteurized, thus is slightly handicapped from the start
since that alone impacts flavor. The flip side to this is that a pasteurized
imported keg of beer will certainly last longer when it is tapped than an
unpasteurized, "live," craft beer. The latter needs to be drunk fresh. A serious
beer drinker should patronize only conscientious draft pubs that keep at least
a few tap handles devoted to local craft brews and ensure that they remain
If a beer fails to live up to its obligation of being fresh, send it back over the
bar-politely of course. Beer condition must always be the primary concern of
any good bar. Always remember, when confronted by a long line of tap
handles in a bar that boasts of its multiple offerings, your first question to the
bartender should be, "What’s fresh?"