Reducing enviromental impact of beer consumption.

[adam2]

As is well known, draught beer dispensed from re-useable kegs or casks is generally considered "greener" than that from returnable bottles and much greener than beer from disposable bottles or cans.

There is however a third option, of beer delivered by hose from a road tanker, into tanks in the pub cellar. This probably has the least environmental impact, and also saves increasingly expensive labour in handling crates, kegs, and casks.
Tank beer was popular in the UK decades ago but is now little used.
There are three systems.

The simplest uses a spherical stainless steel tank in the cellar, into which beer is pumped from a road tanker. Before filling, the tank must be washed out by the publican, this can be semi automated. It uses a lot of water, but less than used to wash out a corresponding number of kegs. To serve the beer, the tank is pressurised with carbon dioxide or with a carbon dioxide and nitrogen mix. shelf life is at least a week, maybe several weeks. The tanks can be refrigerated at lower energy cost than cooling the entire cellar.

For real ale, or cellar conditioned beer, the tanks have a disposable plastic bag liner, the beer complete with suspended yeast and hops is pumped into the tank, allowed to undergo a second fermentation in which the sediment drops to the bottom of the tank. Serve via a handpump or an electric pump. If desired, carbon dioxide at a VERY low pressure may be applied to the top of the tank as the beer is used to prevent oxidation and spoilage. Shelf life of a full tank is a couple of weeks, and once started is a few days if air is admitted, at least a week if carbon dioxide is applied.

The third system is for keg type beer that is supplied clear and ready to drink, this is pumped into a disposable plastic bag within the tank, which is then sealed and pressurised with compressed air. The air does not directly contact the beer which therefore keeps well. The beer retains the optimum level of carbonation, without either going flat, or becoming over fizzy.

I can see a return to such systems at least for the more popular beers in busy pubs.

[BritDownUnder]

One hopes that enough pubs stay in business for these methods to take hold. Every little helps for the planet I suppose.

Does beer act as a natural anti-bacterial then?

As an aside I bought an old beer keg as part of a greenhouse heat storage experiment that I will conduct when I have the time.

[clv101]

Does beer act as a natural anti-bacterial then?

Beer is (historically) a safe/clean drink, this has less to do with the beer itself and more to do with the process involved in brewing. The malt is boiled for an hour (sterilised) then fermented and stored away from oxygen and pathogen contamination. The alcohol and hops help with preservation but it's mostly the boiling and subsequent sealing that makes beer safe.

[Catweazle]

Hops have some very useful anti-microbial properties that are still being researched. Sadly the huge hopfields of Kent are much reduced, replaced by orchards, the smell of the ripe hops was wonderful.

[Lurkalot]

I drink beer and have visited a couple of small micro brewery /pubs in my time. I have wondered about the environmental impact. I would think brewing small quanties is likely to be slightly less efficient but then it's consumed yards from where it is brewed so no transport emissions but how to factor in people travelling to enjoy the beers . Is it more efficient for the lorry to bring the beer to my local and for me to walk there than it is for me to travel to the beer. As I understand it a lot of beer is transported to distribution hubs prior to delivery to the pubs. Within a mile of my local we have a brewery and a friend was talking to the owner who said the beer was first taken to manchester ( I'm in south staffs) before it gets to pubs within a few miles of the brewery.