Beer Styles: Bottles, cans, kegs make a difference - part 18

Bottles are filled in a manner to create just the right amount of foaming, or "fobbing"
as brewers call it.  The fob pushes out air, replacing with the beer's carbon dioxide.
This helps reduce oxygen in the bottle and maintain fresh flavors.  All photos by 
Charlie Papazian.

Brewers call it packaging.  Beer drinkers call it a bottle, a can, draft beer, real ale, from the wood, a long neck, stubby, bomber, dinner bottle, a magnum, a growler, etc.

There are several packaging variables that can dramatically alter the overall character and stability of the end product.  Stylistic variability can sometimes be associated with:

1. Packaging lines/systems
2. Bottles, cans and/or plastic PET containers
3. Kegs/draft
4. Bulk delivery
5. Pasteurization

Packaging lines will introduce varying levels of oxygen into the beer, thus influencing stability of flavor.  Brewers go to great expense and lengths to minimize oxygen pickup during the bottling procedure.  If you’ve ever watched a bottling line you will notice a “fob” of foam emerging from the bottle just before capping.  The foaming carbon dioxide helps push air out of the bottle just before capping.Packaging in clear or green glass bottles will influence the stability and character of flavor and aroma. Green or clear (white) glass = bad for beer.  Brown glass = better for beer.  Green glass might be more pleasant to look and may visually influence novice beer drinkers into buying a certain brand, but it also does not filter out the wavelengths of light that cause a photo reaction resulting in a skunky or "cattty" aroma in beer.  Some beer drinkers enjoy this character and may refer to it favorably as an “import-style” character.

Cans have their own advantages and disadvantages.  See  52 small craft brewers now serve beer in a can

Photo right: Cans are filled on a botlling line. Contents "fobbed" and immediately sealed. 

Pasteurization is the process of cooking the finished beer at high temperatures for a short period of time to kill microorganisms. Most beer bottles are batch pasteurized as they travel through a hot water shower on a conveyor belt.  Most draft beer is not pasteurized and this is why is it especially important to always keep keg beer refrigerated.  Draft beer that is pasteurized is done so through a flash pasteurization process.  Traveling through plumbing the beer is raised to higher temperatures and is then quickly chilled as it travels through plumbing on the way to the keg. will affect the quality of the product.  The quality of many complex styles of beer are utterly destroyed through pasteurization.

Kegs and bulk containers of beer usually have less of an oxygen to volume of beer ratio in the head space, therefore oxidative reactions are slower.

Photo left: Real ale is cellared in an English brewery where live yeast settle. The beer is moved to the pub and allowed to rest for a couple of days before served.

Real Ale is a style of presenting beer originating in the UK.  Draft beer is either gravity poured or pumped with air instead of carbon dioxide pressure.  The introduction of air begins with a gentle oxidation of the beer flavors that are indicative to the quality of English real ales.  These beers must not be served or kept to warm or they will deteriorate rapidly.  They must be consumed within 2 or 3 days for optimal beer character.  Draft beer has its own culture, tradition, requiring special care. 

Next:  Beer Styles – Marketing impacts beer style - part 19

Guide to entire 27-part Beer Style Series - table of contents