There's little more summery than a cool pint of ale or a cold lager, and as E&T discovers, new technology in brewing helps ensure that your beer doesn't come at the expense of the environment.
Like most industries, brewing has come under pressure to improve its sustainability and, in particular, its use of water, energy and transportation. Brewers of all sizes have responded by turning to technologies both old and new, as they re-engineer their processes to save cost and cut wastage.
Water consumption is one of the industry's biggest bugbears, as it can take as many as eight pints of water to produce one pint of beer. Much of the extra goes into washing and cleaning - brewing beer requires scrupulous cleanliness - and that has often discouraged brewers from recycling water, especially when it was easier just to pour it down the drain and get more from the tap.
Higher water and sewerage prices and greater environmental awareness have changed all that, says Dr Keith Thomas, director of analysis and training provider Brewlab. 'Water is a big issue,' he says, adding that it is now possible for larger breweries to achieve water footprints of three, four or five to one - British regional brewer Adnams, which makes much of its eco credentials, claims its water footprint is down to 3.2 to one, for example - and that two to one may be within reach.
'Reducing water use is partly to do with automation and monitoring,' he explains. 'For example, when making up a cleaning solution, on a large scale you can monitor when it is still effective, while a smaller brewery would play safe by discarding a solution that might still be usable.'
The next big area for savings is, of course, energy, especially the cost of heating water - first to mash the malted grain, turning its starches into a sweet liquid called wort, and then boiling the wort with hops for as long as an hour to add aroma, flavour and bitterness.
'People have been working on new ways of boiling, for example thin layer boiling is more efficient,' says Thomas. As the name suggests, this covers the heating surface with a thin film of wort, reducing evaporation and saving evergy.
As is so often the case, cooling is also a notable cost, whether it be to cool the hopped wort before fermentation or keep the beer cool to avoid spoilage.
Even tiny breweries such as the five-barrel Brodies Beers plant, housed in a workshop behind a pub in east London, can usefully recycle a certain amount of water and heat. Breweries use a heat exchanger to cool the boiled wort, but rather than simply pour the now-warm cooling water down the drain, Brodies pumps it into the copper to be boiled up for the next batch of ale, a trick that brewer Tom Unwin says is increasingly popular with breweries of all sizes.
Larger breweries can achieve much greater efficiencies, although some of the technologies involved require considerable investment. At Adnams, for instance, the company claims to recycle 90 per cent of the steam created during brewing and use it to pre-heat the next brew. It says that this and other technical improvements allowed it to reduce the amount of energy needed to produce each barrel of beer from 51.4kWh in 2007 to 46.3kWh in 2008.
Given that Adnams's annual energy bill is around £800,000, clearly that's a saving worth having. Of course, energy efficiency also translates into big reductions in carbon emissions. This is an area that Adnams has done a lot of work in, looking for energy and carbon savings right through its operations, from brewing and waste processing through storage and transportation.
As well as the cuts to its tax bill, thanks to the UK government's climate change incentives, Adnams is well aware of the low-carbon economy's publicity value, and it scored something of a publicity coup two years ago with the launch of East Green, billed as the UK's first carbon-neutral beer, verified by The Carbon Trust.
To do this, Adnams had to work with a range of other organisations. The University of East Anglia assessed its supply and waste chain, for instance, and the National Hop Association of England helped find an aphid-resistant hop that does not need oil-based insecticides or pesticides and could be grown locally. Adnams also developed a lighter bottle to save on transport costs.
The project has also benefitted from two major investments. One was Adnams's energy-efficient brewery, which it says has cut its gas needs by 30 per cent. The other was its eco-warehouse, which was built using a wooden frame, earth and lime-based building blocks and a hemp-based concrete substitute from Lime Technology. It has a green roof and airlocked doors, and can keep contents at around 13C with no heating or cooling required, claims managing director Dr Andy Wood.
In the first few weeks after the building opened, staff were coming in at night to open doors and windows, letting the cool air in, he says. 'Once we hit the right temperature we shut the airlocked doors and we've required no artificial temperature regulation since then. This in itself saves us six-figure sums every year.'
Of course, a zero-carbon beer isn't possible - Adnams still had to offset some remaining CO2 in order to claim carbon neutrality for East Green - but there is still more that could be done, says Brewlab's Thomas. He points out that breweries actually buy CO2 to use in processes such as bottling, even as they vent away the CO2 that's a by-product of the fermentation of malt sugar into alcohol, so carbon capture could yet take off - or, as he points out, make a welcome return.
'Years ago, breweries used to catch CO2 in canvas bags and use it for pressure dispense - I think it became too much trouble and, of course, CO2 became widely available, plus CO2 for keg dispense does have to be pure,' he says. If captured CO2 can't be used for pressure - and Thomas says there's trials with things such as gas-filled balloons to avoid the purity problem - he suggests it could instead be fed to your waste-treatment algae.
He adds that another way to shrink the carbon footprint is reduce your transportation needs by sourcing locally, which also meets the current fashion for local produce. The problem for brewers is that even if they buy locally-grown barley, few will have a working maltings or malthouse nearby. Small-scale malting was a labour-intensive operation, so almost all breweries stopped doing their own and buy their malt from one of a few large malthouses.
'We could see the re-emergence of small-scale maltings as part of the trend to growing ingredients locally,' Thomas says. The challenge for the brewing technologists is to use automation to replace manual work and shrink today's industrial malting processes to a more manageable size.
If you really want to do something about your beer's carbon footprint, it is time to look at its packaging. Many countries insist on re-usable bottles, which saves recycling all that glass and aluminium into new bottles and cans. Of course, the distribution channel in throwaway economies such as the UK might well baulk at the extra workload and storage space, but local depots and some commonality of bottle design would make it easier to manage.
In any case, the times they are a-changing, and in other European countries where returnable bottles are the rule, such as Germany, the supermarkets have managed to make a virtue out of a necessity, with machines that identify your empties and calculate your refund. Even proprietary bottle designs don't seem to be a big problem - most don't travel too far from the brewery, and clearing houses help the few that do stray find their way home.
The packaging method that is probably the most efficient though is a cask or keg. These are already taken back and re-used - as a wholesale package they are delivered to rather fewer points of sale than your average 50cl bottle which saves on mileage, and most pubs use washable glasses. So if you really want low-carbon beer, head for the pub. Mine's a pint - cheers!