Saturday, January 16, 2010

Should you buy cans or bottles of beer?

Many readers of the Green Machine drink beer and are concerned about their carbon, land, and water footprints that result from their choice of packaging for their beers. There is great debate of whether to opt for aluminum cans over glass bottles. From a taste and quality perspective there is a bias towards glass bottles. I am no beer aficionado and my opinion on quality and taste can only be based on the fact that aluminum cans are coated and do not likely impart any taste to the beer. Also in a blind taste test if the subjects drink the beer out of a glass rather than the original container it has been shown that there is no statistical difference or preference between the two methods of packaging beer.,2933,582616,00.html

Beer packaged in an aluminum can also has a longer shelf life as no oxygen can enter the beer. Caps on bottles do not completely seal out oxygen in the air from diffusing into the bottle and reacting with the beer. Also beer is sensitive to light and photoreactions occur in beer, therefore a can that completely blocks the beer from light is preferable even to amber glass bottles. For the purposes of our eco analysis I will assume that good beer in either method of packaging has no taste difference or price difference and that the consumer is basing their selection purely from a Green perspective.

The analysis of comparative carbon, water and land foot prints is dependant on the following primary parameters. The distance from the brewery to the point of sale, the distance of the brewery from the point of manufacture of the container, whether the container is manufactured from virgin or recycled material (the recycle rate for containers in that location), the distance of the container manufacturer from the recycling center or the glass or aluminum foundry, the source of energy used in the glass or aluminum foundry, and the volume of beer within the container. A local brewery in a major metropolitan area like San Francisco, that does not transport the beer very far for sale nor haul empty bottles very far from their point of manufacturer should continue from a green perspective to use glass bottles unless the recycle rate for aluminum cans is more than 75%. Below this threshold of recycling the mining of bauxite and the upgrading of bauxite to alumina and the final refining of aluminum from alumina simply is too energy, land, and water intensive to displace new glass bottles from an Eco footprint perspective. Remember that the simple act of recycling a single beer can saves the equivalent amount of electricty to run your television three hours.

For larger breweries that are less proximate to their markets, aluminum cans even with a recycle rate of only 50% are likely the more eco friendly option. If the aluminum smelter is in Iceland and the electricity for the smelter is generated by hydroelectric dams, then there is no doubt that an Icelandic brewery should use aluminum cans and not glass bottle. Also I am fairly certain that Iceland has a relatively high recycle rate on their beer cans.

The nutrition value (energy content) of a 12 ounce can of beer is approximately 150 Calories. This is only one half of the energy that was required to produce the can if the aluminum was made from virgin bauxite. If the can was made from recycled aluminum, then the energy content of the beer is about fourfold the energy content of the can. SAB Miller is selling some pretty anemic beer now with only 57 Calories, in this case the sickle cell beer has the same energy content as the can made of recycled aluminum. Drinkers of this type of beer with only 2.5% alcohol don’t really care about taste they only care to be true Green Machines and their selection of this brand is all about eco footprint. Here is an interesting link to the calories in various beer brands. The greater the alcohol content the greater the calories. This makes sense as alcohol has carbon bonds with hydrogen that yield energy when metabolized.

I have used up my space for this week’s blog and I will therefore continue the discussion on beer in my next blog. As they say Skal for Cheers in Iceland. I bid you all Skal and I hope the beer you drink does not hurt your skull. Here is a link on from Denmark on how to say Cheers in many countries.

Please provide comments below. And please recycle all of your beverage containers, plastic, glass and aluminum


  1. As luck would have it, we conducted a double-blinded taste test (N = 9) of of canned vs bottled beer (Heinken) to settle a bet during Thanksgiving - each tester had 2 unmarked cups (one of each beer) and had to choose which cup tasted better. Surprisingly 8 out of 9 people preferred the bottled version and 1 person was indifferent...

  2. Girish This is brilliant and it defies chance as ther is only one in 2 to the power 8 chance of this happeing by chance if the items tasted the same. That is one in 256

  3. This is the best link for beer drinkers