Green beers all round

- Last updated on GMT

Related tags: Beer, Brewing

Green beers all round
Environmental and cost-saving measures are at the heart of improvements in large and small breweries alike, reports Graham Holter

Technology and beer do not always make happy bedfellows. The myth of 'chemical lager' has alarmed consumers for decades, and brewers have gone to some lengths in their marketing to reassure the drinking public that their products are essentially no more than water, hops, barley and yeast.

Advertising imagery features fields of swaying cereal crops or the maltster's shovel never the cavernous, computerised buildings from where so much of the UK's beer now originates. There is certainly no mention in the marketing bumph about the genetically modified (GM) enzymes that may have been added towards the end of the brewing process to eat up any hidden 'nasties' that might otherwise turn the liquid cloudy.

One of the big advances has been DSM's Clarex. Its producer describes it as "a unique, proline-specific endo-protease that works by preventing the complex formation between haze-active proteins and polyphenols"

"It doesn't require as low a temperature as polyvinylpyrrolidone (PVPP) and silica gel to stabilise beer, and takes less time, so you're saving on refrigeration," explains Paul Ambler, one of the UK's leading brewing consultants.

GM processing aids

"The enzymes are derived from a GM organism. For some reason that I would not pretend to understand you don't have to declare the use of this thing on the label," says Ambler. "A number of brewers have made a declaration to their customers, especially the supermarkets, that they don't use anything that's GM or derived from GM materials."

Although Ambler regards any public hostility to genetically modified organisms (GMOs) like Clarex as essentially bogus, he can see the PR difficulties such technology presents. Yet he is convinced of the advantages of the product in comparison to the widely used PVPP and silica gel.

"PVPP captures tannins, silica gel captures proteins," he says. "Clarex attacks the same materials but basically breaks them into small molecules that aren't going to cause any trouble in the future. There have been well documented trials to say you need less time and less extreme temperatures." DSM claims the carbon dioxide savings for brewers can be as high as 8%.

Added enzymes are mainly an issue for larger firms. "Small brewers won't be using many enzymes," says Dr Keith Thomas, director of Brewlab in Sunderland, which trains brewers and offers a consultancy service to commercial producers. "When you get to filling 100 to 200 barrels a week you do need better consistency and people may then use enzymes."

Thomas believes that "to some degree, in the long run, there will be GM yeast, and maybe barley and hops". Yeast strains could be developed to achieve faster fermentation, with greater stress resistance, an ability to work at higher gravity and to digest a wider range of sugars, and which can encourage certain desirable flavours while removing others.

Excluding oxygen

Oxygen is the enemy of the brewer, and is increasingly excluded from the process. Former Boddingtons head brewer Paul Buttrick, now a brewing consultant with Beer Dimensions, says there have been major developments in the way that casks and other containers are filled.

"One of the big advances of the last 20 or 30 years is the fact that, once the beer has been brewed, all the processes are designed to exclude oxygen," he says. "Excluding air is very important and it's a very simple process.

"Whenever you're moving beer through the process and into a pack, you make sure that all the air has been excluded first. If you put beer through a pipe, the pipe would be full of air. In breweries now the pipe is filled with water or a gas such as nitrogen or carbon dioxide so there's no air. They're measuring oxygen now in quantities like 100 parts per billion."

Steve Midgley is md of Microdat, which has developed a peristaltic pump system for its automatic and semi-automatic cask fillers, which excludes oxygen and also has significant environmental benefits.

"The problem with filling in the traditional way is controlling the flow of any product that has gas in it. You can't control the flow of beer from the vessel into another container with a valve," he explains.

"The traditional method of controlling beer flow is using counter pressure: you fill the cask with gas to equalise the pressure, then release the gas to fill the cask up. It's expensive, and it's not very green. "The problem for a small brewer typically is that they tend to have vertical vessels in which they store the beer. They open the valve, the beer gushes out and you end up wasting a lot of it on the floor. At the bottom of the tank the beer flow is very slow, wasting time and potentially beer.

Effluent issues

"Effluent is one of the biggest problems for beer producers. If you put beer down the drain it tends to do a lot of damage to the sewage works. The big brewers are spending a fortune on new effluent plants."

Buttrick agrees that the effluent issue is "huge" for beer producers. "Effluent from breweries, things like beer and yeast and malt sugar from wort, is very high in chemical oxygen demand," he says.

"Brewers are doing more and more not to put anything down the drain. Quite a lot of them, particularly the really big ones, are building their own water treatment plants. They end up only returning water to the waste water system that's of high quality. Some brewers actually return it to rivers at the standards of drinking water."

Thomas says that water and effluent charges can be as big an expense for brewers as malt, which is why many are investing in off-the-shelf or bespoke treatment systems populated with microbes capable of devouring yeasts and other organic matter. Some are experimenting with reed beds. Larger brewers, according to Ambler, are using reverse osmosis technology to clean their waste water.

Environmental concerns and rising costs have encouraged brewers to be more efficient. At one time, Buttrick notes, it took between seven and 10 pints of water to produce one pint of beer. Now it's more like four to six. Carbon dioxide from fermentation is reused, sometimes to carbonate packaged beer.

Larger brewers are using biomass boilers which use spent grains as fuel, heat exchangers make the process more efficient, and boiling times have also been shortened.

Ambler says: "There's a sonic system that uses live steam injection, and there you could certainly talk about halving boiling time. But hops still take time to isomerise so you need to have a fairly modern hop preparation, and that's not going to be adopted universally."

Another major development has been the arrival of single-use kegs, which allow brewers to ship beer in lightweight containers. Most models are plastic but are not fully recyclable, though they require no cleaning and steaming, and are less prone to theft. Ambler favours the Schafer designs, in lightweight stainless steel, but believes the Ecokeg and KeyKeg rivals are "good ideas worthy of further development"

Sterile filtration

In the future, pasteurisation the miracle which first allowed packaged beer to be marketed may become a distant memory. "More and more people are changing to sterile filtration rather than pasteurisation," reports Ambler. "There's no doubt that a traditional pasteurisation does alter the flavour of beer.

"Greene King has moved to sterile filtration and Shepherd Neame has destroyed its old bottling hall to install a sterile system. Normal filtration ends up with a beer that looks bright but there will still be some yeast in it, and possibly some other organisms. There are something like 10,000 yeast cells per millilitre in apparently bright cask beer. With sterile filtration the beer goes through a membrane to sieve out microbiological material."

Thomas accepts that in the past "a lot of bottle-conditioned ales haven't been very good" due to shortcomings in smaller bottling units. "They tend to be contract bottled now, both filtered and bottle conditioned beers," he says. "Smaller brewers don't really go in for pasteurisation. Filtration does the job for them and they accept the short shelf-life."

Experiments are now taking place which could see ultraviolet light already used to take micro-organisms out of water in the brewing process employed to do the same job in fermented beer. The cost savings could be considerable and there should be no issues in marketing such a natural process to consumers who would like to believe that their pint is as pure as it can be. FM

-------

Making less demanding beer
Lorien, the West Midlands based engineering company, is helping a major brewer reduce its energy demand at one of its UK sites. Over 30 targeted investments have so far been made in every part of the brewery, canning and packaging plant.
As a result, from October 2008 to September 2009, energy efficiency has improved from 131MJ/hl to 116MJ/hl, according to Lorien - an 11.4% reduction.

Projects include a low-pressure spent grains conveyor; new steam boiler hot water softeners tha re-use excess brewing liquor; carbon dioxide vaporisers that use waste heat from refrigeration; automation of can end-rinse water supply; heat recovery and improved filtration system for keg washing; new induction lighting, and balancing hot liquor production, storage and use.
The site is now leading the organisation’s western European breweries for heat savings, Lorien says.

KEY CONTACTS
■ Beer Dimensions 01565 651389
■ Brewlab 0191 514 4746
■ DSM 01773 536500
■ Ecokeg 0191 487 31 27
■ KeyKeg 00 31 223 661088
■ Lorien Engineering 01543 444244
■ Microdat 0113 244 5225

-----

Related topics: Drinks

Related news

Follow us

Featured Events

View more

Products

View more

Webinars