Water Filtration : Common problems and treatment procedures.
With the use of cartridge filtration, sediment, taste & odors, and lime scale can be treated successfully and economically. These cartridges range in size from single application filters to large systems that will filter all of the beverage water for an entire restaurant or store. These systems can include permanent mounting brackets, pressure gauges,shut off valves for filter changes,purge valves and quick change systems. Some systems have a permanent housing with replaceable cartridges. Other system's cartridges are contained in a metal casing which is completely discarded. Cartridges combining a scale inhibitor with carbon or separate feeders using polyphosphate cartridges are commonly used. Triple action filters combine sediment filtration, carbon, and scale inhibitors in a single package. It is very important to follow manufactures' guidelines concerning flow rates, capacities and equipment compatibility. A maintenance schedule should be implemented so that filters are changed before they become exhausted, insuring a consistent beverage quality. Filters should be sized so that maintenance intervals occur every 6 months.
High quality water is an essential ingredient in brewing a good cup of coffee or pot of tea. Municipalities normally provide safe drinking water, and are required by law to meet health standards and to document the test results. While safe to drink, this water isn't necessarily the best water with which to brew coffee or to make other beverages. Filtration and treatment can improve beverages while protecting your equipment from service problems caused by certain water conditions.
Sediment consists of small particles suspended in the water. These particles may be rust flakes from the water pipes, sand grains, small pieces of organic matter, clay particles, or any other small particles in the water supply.
Water that has a high sediment level can change the aesthetic value of the finished beverage. It also can have a detrimental effect on the performance of your equipment. Sediment can cause blockages in the strainers, flow controls and even the solenoids inside your equipment. This blockage can cause reduced accuracy in the water-to-coffee ratio that is so critical in the brewing process.
A sediment filter acts as a sieve to remove these particles. Filters are rated by the size of the smallest particles that they remove, measured in microns. A micron is one one-thousandth of a millimeter. To compare, a human hair is nearly 70 microns in diameter, and with the naked eye about 40 microns is visible. Remember that sediment filters are just that, they do not remove substances like salts or dissolved minerals. The recommended micron size of a sediment filter for brewing equipment is in the 5-20 micron range.
A common problem in beverage equipment is liming, or scaling, caused by excessive hardness or mineral content of the water. Heating the water causes lime to precipitate and form lime scale. If left untreated lime scale buildup can cause numerous problems in coffee brewing equipment. The list includes the insulating of heating elements, reduction in volume of hot water in your equipment's tank and clogging or completely closing the tubing.
If lime scale has insulated the heating elements, their efficiency is greatly reduced. Lime scale buildup in the hot water tank will reduce the volume of water available and increase recovery time. You can recognize a lime scale problem in the tubing and smaller orifices in your equipment. This is where you use that funny looking long spring that is included with your brewer. You use it in the spray head tube to knock down the lime scale build up.
To overcome the lime scale situation in filter drip brewers and, at the same time provide you with a great tasting cup of coffee, the use of polyphosphate crystals is highly recommended. With this system, a polyphosphate feeder is attached to the cold water line. The flowing water dissolves the polyphosphate crystals at the proper speed. This action prevents the deposits of lime on your equipment by keeping the lime in suspension. No adverse effects on extraction time or on coffee flavor have been detected.
Espresso machines work differently from filter drip brewers. They are essentially steamers. Most manufactures of espresso equipment recommend the use of softened water to prolong equipment life. Softened water causes problems with the filter drip brewers by clogging the brew filter and preventing proper extraction. Since only a small amount of water is used with the espresso equipment, water softener cartridges are practical.
Taste,odors and chlorine:
Many tastes and odors in water are due to naturally occurring substances. Chlorine, on the other hand, is added as a disinfectant to control harmful bacteria.
Tests have shown that chlorine levels in water over approximately .5 PPM are objectionable. Levels of this concentration or greater can adversely effect finished beverage products, causing a bitter taste. In addition, high concentrations of chlorine is dangerous to your equipment. It can be corrosive to the stainless steel and eat away at the metal causing more problems that are not warranted by the manufactures.
Activated carbon is the most common used medium to remove these elements from the water. Base materials for carbon include coal, coconut shells and wood. After being carbonized, this material is "activated" with steam under closely controlled conditions, enlarging the pore structure of the carbon, giving it a very large surface area. This press gives activated carbon its capacity to remove taste and odors. Absorption is the mechanism in which the molecules that cause taste and odor to adhere to the carbon. This happens within the pore structure of the carbon.