The Beer Brewer

It’s the backbone of the British pub cellar – but half of Brits admit to never having tried a pint of classic Cask Ale.
A hefty 48 per cent of those questioned hadn’t ever sampled the national drink, despite the reported surge in popularity over recent years, so champion of Cask Ale, national pub group Ember, has launched Britain’s first ever Cask Ale Menu to aid curious drinkers.
And, to reach the younger age groups of 18-24 and 25-34 year olds – ranking as the least savvy-suppers of Cask – Ember has launched a Cask Calculator facebook tab to generate suggestions for these younger drinkers.
The West Midlands and North East regions come out on top as Cask drinkers, with 57 per cent in both regions having sampled Cask Ale.
Only one in three of those in Northern Ireland – traditionally stout drinkers – have tried Cask, while Londoners are also behind the times.
Andre Johnstone, senior marketing manager at Ember, said: “As the national drink, it’s pretty shocking that half of British pub-goes haven’t ever tried Cask Ale. With varieties now spanning from dark and rich through to lighter, easy drinking brews, there really is a pint for everyone and every occasion.
“We believe our Cask Ale Menu is the first available in the country, guiding guests through the 12 ales available at Ember this winter – and with the addition of the Cask Calculator facebook tab to inspire younger drinkers, here’s to a host of converted cask drinkers!”
The fun Cask Calculator on facebook works by aligning someone’s usual tipple (wine, beer or spirits) with a favourite dish (pie and chips, pasta or curry) and a chosen personality type (laidback, outgoing, traditional) to suggest a Cask Ale to suit.
For more information on Cask Ale at Ember and try out the Cask Calculator, please visit www.facebook.com/emberinns

What did our Cask Calculator suggest for cask-cautious celebs?

Chris Moyles, a laidback, perennial pie lover who loves his beer should try Acorns Barnsley Bitter.

Outgoing breakfast girl Christine Bleakley should swap the wine with her pasta for Williams Brothers Ginger Beer.

Dancing on Ice and Hollyoaks star Jennifer Metcalfe has admitted in a recent interview to loving her curries even when on a health kick. So instead of teaming her masala with a vodka and diet coke, the Cask Calculator suggests she reaches for Rudgate Jorvic.

Luscious foodie Nigella Lawson often teams a gourmet pie with a nice glass of red, but she should instead try Yorkshire Terrier.

Lad about town Danny Dyer could leave his hard-drinking behind if he teamed his pie with a pint of Hook Norton Jackpot.

*Research conducted December 2010 with a sample size of 3,000 British adults.
** Celebrities cask suggestions generated by the cask calculator are not endorsed by each celebrity.

Ends

Issued on behalf of Ember Inns by McCann Erickson Communications House, Highlands Road, Shirley, Solihull, West Midlands B90 4WE. For further information please call Lauren Bluck on 0121 713 3797 or Stephanie Anthony on 0121 713 3794. Or e-mail: lauren.bluck@europe.mccann.com or Stephanie.anthony@europe.mccann.com.

About Ember Inns
Ember Inns offer a warm and friendly ‘home-from-home’ environment, perfect for catching-up with friends and family over a drink or a bite to eat. Great quality food – including traditional pub favourites with a twist, tantalising lunch options, hearty main meals and a host of sharing plates – are served from midday until 10pm and guests can look forward to a host of exciting events encouraging them to explore the best in new wines, real ales and food.

See our previous article for part 2

Beer haze may also be addressed during maturation (pre-filtration) using precipitants. Proteolytic enzymes such as papain can be used to remove (hydrolyse) haze proteins, although the enzyme can also have a negative impact upon finished product, as it is relatively non-specific and often hydrolyses foam active proteins to destroying a beers head. However, research conducted by Eden et al (2005), using a proline specific protease enzyme (from the microorganism Aspergillus niger), resulted in the prevention of chill haze in beers without having a negative impact on the foam active proteins, as they are very low in proline. This enzyme may prove to be a viable option for brewers in the future.

Tannic acid (a polyphenol) interacts with HA proteins to form insoluble precipitates in the beer. These precipitates are frequently voluminous, thus beer losses via this mechanism can be large.

Fining with agents such as gelatine can also remove HA protein.

Microbrewers often rely on the more traditional method of extended cold storage and filtration to precipitate and remove HA material, which can result in a less stable product.

part 1 of this can be found Beer Clarity part 1

continuing our article on Beer Clarity and hazes

Chill hazes consist of small (0.6µm) particles and are a result of HA protein-polyphenol (catechin) cross linking, via hydrogen or hydrophobic bonding, at temperatures of 0 – 4°C. Such hazes re-dissolve upon warming to 20°C as these bonds are weak; however, polyphenols such as catechin are subject to oxidation during beer storage, producing polymers, which form large particles (1 – 10µm) and permanent hazes when covalently cross-linked with HA proteins.

Beer haze is typically measured via nephelometric methods, which are based upon the principle of light scattering when a beam of white light passes through a solution carrying a dispersion of particles (Fischer, 1966). The size, concentration, shape and differing refractive index (compared to the media) of the particles dictate the amount and intensity of the light scattered over a range of angles. Increasing amounts of particles (haze) in the medium corresponds with increased capacity to scatter light. Nephelometric instruments primarily measure the intensity of light scattered at a 90° angle from the incident beam. Measurements at narrow angles, i.e. 13°, are sensitive to large particles (1 – 10µm) that often form visible hazes, whereas 90° angles are sensitive to pseudo or invisible hazes that form from smaller particles < 0.1µm. Larger particles are (usually) removed during the filtration of beer, but smaller particles may remain in the final product to promote colloidal instability. Thus, beer haze measurements are usually performed at 90° angles.

Large, modern commercial breweries address the problem of protein-polyphenol colloidal instability via the use of adsorbents during beer filtration, such as silica gels, which bind to HA proteins, or Polyvinylpolypyrrolidone (PVPP), which binds to HA polyphenols. Both compounds are highly selective for their respective HA material.

Beer Clarity part 1

Beer is subject to colloidal instability during storage. Chill filtered beer initially remains haze free, however, as the product ages it passes through a series of metastable colloidal states, whereby chill hazes and eventually insoluble (permanent) hazes form, primarily as a result of protein-polyphenol interactions within the product. Haze reactions are significantly accelerated with increasing temperature, due to an increase in the rate of reactions (Kunze, 1999).

Proteins and polyphenols are natural components of beer which are extracted from malt and hops. Haze active (HA) proteins contain high percentages of the amino acid proline and are thought to be the degradative products (as a result of the malting and brewing process) of barley hordein. Globulin and albumin proteins are also regarded as haze active, as they associate with polyphenols in the beer to form hazes upon removal of the proline containing proteins.

The polyphenols primarily involved in haze formation are barley flavanoids such as catechin, or polymers of the latter, proanthocyanidins.

The mechanism of haze formation is the following: Haze active proteins contain a number of active sites, thought to be the proline residues, which have a specific affinity for polyphenols. If polyphenols have two binding ends, they are capable of linking protein molecules together, forming colloidal particles, which create haze. Smaller colloidal particles initially form in beer, as there are insufficient amounts of polyphenols to link any more than two protein molecules together, hence light hazes form. Larger particles and increased haze can form when polyphenol levels approach those of the protein (due to oxidative reactions during storage ), as polyphenol linking of the proteins can form large networks.

Beer colour is the result of the concentration of highly coloured melanoidin and caramel compounds in solution. These compounds are primarily formed via Maillard type reactions between aldose type sugars and amino acid groups, which occur primarily during extreme heating stages of the malting and wort production phases of the brewing process i.e. malt kilning and wort boiling. Melanoidin compounds are extracted from the malt during mashing and form during boiling. Therefore, the desired colour of a beer may be achieved by employing malts of particular colour and boil times of appropriate duration.

However, as packaged beer may contain amino acids and reducing sugars in solution Maillard reactions may still occur in the product, particularly if the beer is subjected to storage under conditions that favour this reaction, namely elevated temperatures, long time periods or a combination of both. Studies have attributed colour increases during ageing to such Maillard reactions.

The polyphenols in beer are also subject to degradation via oxidation reactions catalysed by light, oxygen, oxidising agents, and heavy metals, to form darker coloured quinonoid bases that result in an increase in beer colour.

The diagram below shows a typical evolution of lambic fermentation over time.

Key to the diagram: 1 : Ethanol, 2: Lactic acid, 3: Ethyl Acetate, 4: pH, 5: Extract content, 6: Acetic acid

The following table shows the characteristics of three differnent styles of Lambic Beer:

The soft and hard classifications are due primarily to the acid contents of the beer, whereas the rope characteristic describes the oily consistency of the beer due to high lactic acid levels.

The finished product is characterised by high levels of lactic acid, acetic acid, ethyl acetate and ethyl acetate. Final gravities are in the region of 1.008 (2.2 oP) 1.012, 3 oP, DMS levels are reduced to approx 100pb and diacetyl concentrations between 45-80ppb. Final 2,3 butanediol levels are not available.

Beers of the lambic style are described as having vinous aromas and tastes accompanies by ‘horse blanket’ or ‘goaty’ characterisitics, which appears to be attributable to the contained acids and products from Brettanomyces activity. Thin mouth feel is also noted, due to the low levels of residual dextrins.

The spontaneous nature of lambic fermentation and the varied spectra of bacteria and yeasts encountered in differing breweries that are responsible for such fermentation, may produce beers with differing characterisitics.

Brettanomyces species, particularly B. limbicus and B. bruxellensis also become active during this period, from approximately 8 months onward (figure to follow). These yeasts are capable of fermenting dextrins (found in relatively high levels in lambic wort), maltotriose and maltotetraose, producing small amounts of acetic acid and ethanol. However, it is the production of unique flavour and aroma compounds that characterises the activity of Brettanomyces. Brettanomyces exhibits a high esterase activity, primarily resulting in the synthesis of large amounts of ethyl acetate and ethyl lactate. This esterase also cleaves iso- amyl acetate esters, thus accounting for its low concentration in lambic beer.

Tetrahydropyridines are also produced from ethanol and the amino acid lysine, which impart a ‘mousy’ or ‘horsy’ aroma to the beer. Volatile phenolics, with medicinal, ‘barnyard’ or ‘animal’ type odours are also from from 4-ethyl phenol and 4-ethyl guaiacol compounds.

Brettanomyces activity also leads to a significant increase in caprylic (C8) and caprix (C10) acids (small amounts are formed during earlier Saccharomyces acitivity) along with their associated esters, ethyl caprylate and ethyl caprate. These compounds produce a characteristic ‘goaty’ aroma/flavour to the final product. Capric and caprylic acids are short chain fatty acids and are thought to be by-products of yeast metabolism, produced during lipid synthesis by a yeast cell and released into the medium via leakage through membranes damaged by ethanol, or as a consequence of an autolytic mechanism. Higher temperatures, aeration and agitation during fermentation reduce the amounts of fatty acids in beer. Reduced aeration/agitation produced higher concentrations. The combined threshold for C6-C12 acids is 10ppm, beyond which ‘goaty’ aromas arise. C8 acid levels in gueuze as 12.4 – 21.85 ppm and C10 acids as 2.3 – 3.9p ppm.

Brettanomyces is active until the end of the fermnetaion period. Acetic acid bacteria of the genus Acetomonas and a number of oxidative yeasts (Pichia, ) are also found during lambic fermentations, however their influence is often minimal.

As the Saccaromyces species decline once the primary fermentation is completed (2 months), the secondary or lambification (acidifcation) phase, initially involving the hop tolerant Pediococcus damnosus, takes place. P. damnosus is the primary producer of lactic acid in lambic beer, as it is a homofermentative organism producing only lactic acid from the metabolism of glucose, via the EMP pathway. As lactic acid is a key component in lambic flavour, its production is considered here: Glucose undergoes enzymatic cleavage and substrate level phosphorlyation, producing glcyeraldehyde 3 – phosphate, a proportion of which is converted to pyruvate. Lactic acid is produced from pyruvate by the the enzyme lactate dehydrogenase. No gas is evolved. The taste threshold for lactic acid is 400ppm. Final concentrations are indicated as between 492 – 3677ppm.

Fermentation at temperatures above 20oC are required for P. damnosus growth, therefore increasing temperatures beyond this level will stimulate lactic acid production as cell numbers increase. P. damnosus is a also a facultative anaerobe, thus the exclusion of air during P. damnosus activity will presumably facilitate the further production of lactic acid.

P. damnosus is also a producer of diacetyl, prodcuing up to 200ppb during this period. Acetoin is also produced as a consequence . The production of large amounts of lactic acid result in a drop in beer pH from 4 to 3, with a gradual lowering of residual extract.