dictionary defines water as follows: The liquid that descends from the clouds as rain, forms streams, lakes and seas, and is a major constituent of all living matter and that when pure is an odorless, tasteless, very slightly compressible liquid oxide of hydrogen H2O.
Water comes from the sky, but only 30% ever reaches the ground. The remaining 70% evaporates and begins the hydrologic cycle again. The remaining water finds its way to reservoirs, into streams, water towers and wells, or it may seep into the ground and be captured in water tables.
In the course of its journey into your beverage, water attempts to dissolve everything that comes in contact with it, while adding those dissolved items to its own make up. As a result, water often contains many of the characteristics of those substances. Because of this tendency, water seldom remains “odorless (and) tasteless.” Instead it may taste like the rocks it passed over on the way to the water supply or the chlorine introduced into it by well-meaning city officials.
Beverage equipment failures are an expensive result of the presence of impurities in tap water. Dirt, sand, sediment and suspended solids will clog equipment and prevent proper water flow. Chemicals and organics can cause corrosion of metal surfaces, while dissolved solids and minerals in water present the greatest problem for equipment, causing limescale build up, reducing equipment efficiency and finally resulting in a total breakdown.
So is there a need for water filtration? To answer that question, consider the following:
The answer, of course, is yes. Since water comprises such a large percentage of dispensed beverages - coffee, espresso and tea along with juice and carbonated soda, it is an essential part of a pleasing customer experience. Fortunately, due to advances in water filtering technology, operators have better control and more options than ever to assure that the water used for their beverages contributes to a great customer experience.
- A cup of coffee is 98% water.
- 60% of beverage equipment failures are due to water quality.
- A credit card thickness of lime can create a 30% energy deficiency.
Water and Coffee
Fresh, good-tasting water is essential to coffee and mineral content can affect taste. For best results, water should not exceed these parts per million (ppm) of dissolved minerals:
To give you an idea of the meaning of the term grains of hardness, let me give you an example: one gallon of water containing five grains of hardness - which still falls in the range of ideal water - contains limescale equal to an aspirin tablet.
- Ideal – 50 -100 ppm (50-100 mg/L) or 3 to 6 grains of hardness
- Acceptable – Below 300 ppm (300 mg/L) or 18 grains of hardness
As you can imagine, limescale buildup caused by water high in minerals can be a particular problem with coffee equipment. Besides coating the insides of water tanks, lime scale can clog sprayheads so that water is inhibited from spraying over the coffee or tea. Your customer might get a bad cup of coffee and blame the coffee beans, the length of time coffee has been in the decanter, or even chastise the server. But the real culprit might be the water.
Water and Tea
All tea, both hot and iced, is affected by water quality. Because of tea’s light flavor, the quality of input water is crucial to the beverage.
The clarity of tea is particularly affected by mineral content in water. Water hardness, caused by calcium and magnesium content in excess of 200 ppm, can cause clouding in iced tea. Water with 50 - 150 ppm total dissolved solids or 1 to 3 grains hardness provides the best results, according to the Tea Association of the USA.
An international water filtration company, CUNO Incorporated, classifies water hardness as follows:
Water hardness is caused by a high mineral content. Tests show any hardness in excess of 200 ppm can cause clouding in iced tea. Chemical taste and/or odor caused by chlorination of municipal water and the presence of hydrogen sulfide in the water can also detract from tea flavor. In addition, the presence of particulate matter in water can cause scale and lime accumulation, detracting from the operational efficiency of automatic tea steeping equipment.
- Soft Water: 0.0 - 1.0 gpg (0.0-17.1 ppm or mg/l)
- Slightly Hard Water: 1.0 - 3 1/2 gpg (17.1 - 60 ppm or mg/l)
- Moderately Hard Water: 3 1/2 - 7.0 gpg (60 - 120 ppm or mg/l)
- Hard Water: 7.0 - 10 1/2 gpg (120 - 180 ppm or mg/l)
- Very Hard Water: Over 10 1/2 gpg (180 ppm or mg/l)
To minimize problems associated with a less than optimal water supply, the Tea Association recommends installation of filtration/conditioning equipment that meets the following criteria:
In addition, the Tea Association of the USA recommends water softening equipment to reduce or eliminate water hardness caused by excessive mineral content. In extreme hard water areas, a preventive maintenance service arrangement may be necessary.
- Mechanical particulate filtration at a minimum 20 micron level (40 microns can be seen unaided).
- Activated carbon filters to remove soluble organic chemicals, taste and odorcausing compounds and chlorine.
- Contain lime/scale inhibitors to keep calcium and magnesium in suspension and separated from product bonding and reduce buildup on heaters and spray heads.
- Have easily replaced cartridges.
- Have a minimum of 6 months cartridge life for average commercial use.
- Contain one all-purpose filter effective for all identified problems except water hardness.
Water Filtration Systems
Addressing water quality issues requires that you understand your water. There are a number of water filter options available so that you can confidently offer your customers the best beverages possible.
The first type of filtration system is sediment filters. Tap water often contains suspended particles such as dirt, rust flakes, sand and other organic materials. Sediment filters trap this debris and prevent if from clogging up equipment or showing up in a beverage.
Like anything, sediment filters have both positive and negative effects. Sediment filters trap foreign matter floating in water; however, they are not intended to correct water hardness or taste and odor problems. Filters are excellent for use with both espresso machines and coffee brewers. Because soft water is better for use in espresso machines, sediment filters are ideal for this type of application. They also work well in areas where water hardness is not an issue.
Carbon filters oxidize all particles on the surfaces of the carbon particles, leaving the surfaces to attract and hold organics along with taste and odors like chlorine. Using carbon filters will improve the taste and odor of beverages, however, like sediment filters, carbon filters will not soften water. These filters are also recommended for use with both espresso machines and coffee brewers.
Inhibitors are water filters that reduce the effects of water hardness by sequestering the lime-forming minerals in the water. Inhibitors function without impacting the taste or odor of beverages, and they are also relatively inexpensive. However, if a true water softening filter is necessary, these are not the best choice because they reduce water hardness by only about half. Of course, if this is sufficient, inhibitors are the solution and I would recommend them for many filterstyle coffee brewers.
Ion Exchange Systems are often called “water softeners.” These filter systems exchange calcium and magnesium in the water for sodium. Ion exchange systems are effective in reducing water hardness, and little or no hardness remains in the water if they are used. However, “softened” water can cause filter overflows in filter brew systems and water taste may suffer as well. These systems are acceptable for espresso machines, but not recommend for use with filter-style coffee brewers.
So how do you get around the disadvantages of each type of filter? The answer might be to use a 3-in-1 Filter. These filters combine an inhibitor, sediment removal and a carbon filter into one housing. Siliphos acts as an inhibitor in these filters. A food grade mineral consisting of polyphosphate and silicate compounds, siliphos is colorless, tasteless and odorless. This unique combination works in two ways to inhibit scale and corrosion caused by hard water:
The second element in a 3-in-1 filter is graded density filter media. Water filters are constructed so that the spaces between the fibers become increasingly small towards the inside of the filter. This graded density filter media traps the larger particles on the outer layers and the smaller ones towards the center, ensuring optimum filter life.
- First, it sequesters or “ties up” calcium and magnesium
- Then it coats internal piping with a slippery material called silicate, which won't build up on itself.
The final element in a 3-in-1 filter is activated carbon. Made from a wide variety of materials such as wood, peat, nut shell and petroleum, activated carbon oxidizes all particles on the surfaces of the carbon particles.
Water - we couldn’t live without it. And now you can install water filtering systems that will assure that you can offer the best beverages possible to your customers.
Greg Fisher is senior vice president, commercial sales at Bunn-O-Matic Corporation.