the carbon footprint of beer

After that last post about 10:10, a comment was left from Dunc who said

I'm a craft brewer, and at least 10% of my domestic electricity use is for brewing. I could eliminate that overnight, but if I'm still drinking beer, I'm pretty sure that would actually increase my overall emissions (the bulk of the emissions from commercial beers being located in transport, packaging, and the retail environment, all of which I completely eliminate by brewing at home).

My gut feeling is that he's right about the bulk of emissions not being from the beer itself, but surely I could find some concrete evidence out there.

The Carbon Trust said

The carbon footprint of off-trade beer, the majority of sales, is dominated by its packaging (which for standard size units represents at least 50% of product-related emissions), with the overall footprint of a traditional disposable glass bottled beer generally higher than that of aluminium cans and PET bottles.

Coincidentally, in reading up about 10:10 I came across this article about Suffolk brewers Adnam's.

I've heard of numerous green initiatives they've undertaken in recent years, and my impression is of a company actually trying to cut things rather than just do a little greenwash. (But then, giving you such impressions is the mark of successful greenwash...)

Anyway, this caught my eye.

Adnams has reduced the energy used to produce each barrel of beer from 51.4kWh in 2007 to 46.3kWh in 2008.

The inclusion of an exact figure article set me off on a little arithmetic.

If we take 51.4kWh per barrel as average for beer, and presume that's a normal 72 pint barrel, we're looking at 0.714kWh per pint.

The UK electricity supply emits 460g of carbon dioxide per kWh of electricity.

This makes 328g/pint. That's the same as driving the average car about 2km, or eating four bags of crisps.

I then found the dependable Ask Umbra had covered alcoholic beverages.

Sapporo has started labeling beer cans with carbon footprints; their estimate is that a 350ml can of Black Label beer emits 161g of carbon.

That's about 261g/pint.

Umbra points us to a 2007 study for wine that showed that, in America, transportation accounts for about half of wine's carbon footprint, and the manufacture of bottles a further quarter. It's put numbers on something I've said before, that there's no excuse for Europeans drinking non-European wine.

In 2008 the New Belgium Brewing Company had a serious study done of a six pack of their beer (6x12floz bottles). They found it was a whopping 3,188.8g. By my calculations, that's 889g/pint*.

Perhaps there's something amiss in their having such a huge impact. Then again, it feels more likely that it's due to it being an exhaustive full life-cycle study. Emissions from the company’s own operations and the disposal of its waste accounts for only 5.4 percent of their emissions. They found the biggest single element was pre-chilling beer in those stupid open fridges in shops, accounting for more than a quarter of the carbon.

There are solutions to this, and not just by the obvious move of buying local, unrefrigerated beer (or brewing your own like Dunc). In San Francisco there's Carrotmob, who touted round local stores and had everyone go to the one that would give the greatest amount of the profits to energy efficiency improvements to the store, a total win-win.

THEN THERE'S THE WATER

The really alarming figure in the Adnam's article was this

It takes 8 pints of water on average to make one pint of beer.

(Adnam's have got it down to less than half of that, by the way).

There's so much cleaning of vessels and pipes to be done. But where does this figure come from? Does it include 'virtual water', the stuff used to make the ingredients and containers?

It's something that first hit me four years ago with the Independent's front page that said

The real cost of a bag of salad: You pay 99p. Africa pays 50 litres of fresh water

In soft drinks, made from crops grown in hot and artificially irrigated conditions, the figure can be astronomical.

Coca-Cola's Chief Executive E Neville Isdell said in 2007

it now only takes 2.54 liters of water to make one liter of Coke, compared with 3.14 liters five years ago

However other sources say that

there is as much as 250 litres of water used once growing the sugar cane used in the drink is factored in.

For many places, water is a pressing issue and will become all the more so as population increases and climate change intensifies. Even in well-watered parts of the world, treatment and pumping are large users of energy, so 'embodied water' in a product is part of its embodied energy and carbon emissions.

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* 3188.8g divided by 2040ml (12floz), multiplied by 568 (number of ml in a UK pint)