Dispense, beer

Whilst the formation of biofilms is the obvious consequence of poor hygiene, there is little in the public domain about them in the context of dispensed beer. Arguably the only studies that quantify attached microorganisms in dispense lines are Thomas and Whitham (1996) in a study on-line composition, Fielding, Hall, and Peters (2007) on the use of ozone as a line cleaner, and Walker et al. (2007), who evaluated the use of enzymes as line cleaning pretreatment. 

In the large tied houses or big independent pubs the installation of the so-called beer drive system, ie, beer suppHed by tankers to relatively big cellar tanks combined with sophisticated beer dispensing systems, has been used successfully. The beer drive system might be seen as an alternative to the pub breweries or something which happened prior to the pub brewery period. 

Elavored carbonated beverages, or soft drinks, were developed by apothecaries and chemists in the early nineteenth century by the addition of flavored symps to fountain-dispensed carbonated water. The introduction of proprietary flavors began in the late 1880s. Charles H. Hires introduced his root beer extract in 1876, Vemors s Ginger Ale was marketed by James Vernor in 1880, R. S. La2enby perfected the formula for Dr. Pepper in 1885, and John S. Pemberton developed the formula for Coca-Cola in 1886. Brad s Drink was introduced in 1896 and was later renamed Pepsi-Cola in 1898. 

The foam head created when beer is poured or dispensed, is an important aspect of consumer approval of a particular beer product. Compared with champagne foams, beer foams need to have different properties and be much more stable (beer foam needs to last for about five minutes). A cryogenic electron microscope image of beer foam is provided by Wilson [73]. Consumer preferences for beer foams vary, but can be characterized in terms of foam stability, quantity, lacing (adhesion to a glass surface), whiteness, creaminess (bubble texture), and concentration [852,853], As a result, much work has been done in order to be able to control these properties. 

In the laboratory portion of the project, the students quantify iron in real and artificial surface water samples by UV-Vis spectroscopy. The iron is complexed to the o-phenanthroline (phen) ligands in a buffered solution to create a highly colored orange complex, [Fe(phen)3] The intensity of the complex color is proportional to the concentration, following Beer s Law. Students create a standard series and prepare a surface water sample using modified standard protocols (21). We use autodispensers to dispense corrosive reagents and provide the stock iron solutions this equipment reduces exposure and ensures that the experimental work can fit within the three hour laboratory period. Students measure of the absorbance of their standard series as well as their surface water sample on a spectrometer at X = 508 nm. Students complete the experimental write-up, calculations, data analysis, and assessment during the subsequent laboratory period. 

Cocaine, like opium, also was widely dispensed at pharmacies in solutions of alcohol. Queen Victoria was fond of marijuana. Thomas Jefferson smoked marijuana grown on his plantation. He believed that marijuana should be sold at grocery stores the same as beer or wine. 

The foam head created when beer is poured or dispensed is an important aspect of consumer approval of a particular beer product. Compared with champagne foams, beer foams need to have different properties and be much more stable (beer foam needs to last for about 5 min). A cryogenic electron microscope... 

The traditional kinds of physicochemical characterization methods have been applied to beer foams, but potentially surface-active compounds in beer are so numerous, and their interactions are so complex that complete brewing and pour-ing/dispensing tests are still needed. There are also manyfoam stabilitytests available (see Section 2.6.2), but none has been universally accepted in this area [72]. 

The generation of a yeast-head or barm is a separate process from the maintenance of the head. Some yeasts form unstable heads and other strains will only barm in vessels over a critical volume and height. Barm stability is possibly akin to the stability of beer foam at dispense, that is, foam-retention. 

The beer is stored at the brewery for widely vary ng periods, often seven days or even less, preferably at a temperature between 13-16°C (55-60 F). If too much yeast is suspended in the beer or the temperature too high, the secondary fermentation may be too violent. When the casks are vented the beer foam gushes out of the cask and is lost. If too little yeast is present in the beer, secondary fermentation is too slow and insufficient carbon dioxide is dissolved in the beer at dispense. The volume of finings used depends on the amount of yeast present in the cask (see p. 698 et seq,)... 

When sterile filling is called for, the sterile bottles are conveyed in sterile tunnels, the filling head is shrouded and ideally the filler and crown closure machine are housed in separate, but adjacent, air-conditioned rooms. In hot-filling, the beer is dispensed at 65°C (149°F) which tends to sterilize the bottle. Care has to be taken to ensure that bottles are scrupulously clean and free of flaws otherwise uncontrollable fobbing occurs. Fillers are cleaned in-place, usually at the end of a large batch of beer. Bell housings and filler tubes are often sprayed continuously with a mist of either a chlorinated solution or an iodophore (see Chapter 21). Provision is also made on some machines to jet water at high pressure if a bottle breaks while on the filler. 

Some breweries deliver pasteurized beer, similar to that dispensed into kegs, in tanker wagons directly to the point of sale. The beer is pumped through a hose from the wagon into cellar tanks in the inn cellar. Such cellar tanks (usually about 8 hi or 5 brl) may be aluminium or stainless steel and may be equipped with cleaning-in-place facilities and also with means of maintaining constant pressure. Other cellar tanks of similar size are of mild steel construction and the beer is filled into a disposable plastic bag which acts as a liner to the tank. In such tanks, the beer may be emptied from the bag by applying gas pressure (usually air) within the top of the tank upon the plastic bag. It is not normal to use tank beer systems unless the beer within the tank is likely to be held for 4 days or less. 

In the dispense of keg beer, the relationship between gas content, temperature and pressure is very important. If for example a beer at 10 C (50°F) has to have a carbon dioxide content of 2 voL, the equilibrium pressure is 0 7 bar over-pressure (or 10 5 psig). Were the temperature to fall to 4 4 C (40°F) and the pressure maintained, the content would rise to 2 4 vol. so that the beer may be difiScult to dispense. On the other hand if the temperature rose to 15 5 C (60°F), the gas content would fall to 1 65 vol. at the dispense tap and the beer would foam uncontrollably. Fobbing of this kind is usually a result of having an incorrect balance of temperature, pressure and carbon dioxide content. However, compensation has to be made when gas pressure has to force beer along long runs of dispense pipe or up a vertical pipe. Thus for every horizontal metre an additional 0 011 bar is required and for each vertical metre, an extra 0 108 bar. If, however, the pressure required to take the beer to the dispense tap is, because of height or distance, in excess of the equilibrium pressure then a pump must be installed. 

The theory of operation of the photometric method for determining dispensed liquid volumes is based on the Beer-Lambert law, which... 

Each year, over 100 billion aluminum cans, billions of glass bottles, and thousands of tons of paper and plastic are used in storing and dispensing soft drinks, juices, processed foods, grains, beer and other products. In the United States approximately 5.5 million tons of paper are consumed each year in packaging materials, which represents about 15% of the total annual domestic paper production. 

Acetobacter Wort, beer dispenses, and cask-conditioned ales and barrel-aged ales, brewery biofilm Sour, vinegary Hazy, ropiness Acetic acid... 

Glucano- bacter Wort, beer dispense and cask-conditioned ales Sour, vinegary Hazy Acetic acid, acetate... 

---