01 Feb Standards for Ingredient Water
The Water Standard for beverage service for a national or international organization with operations over a wide area should mandate the use of approved Public Water Supplies, or the equivalent.
By U.S. standards, that means even a private well used for nothing but a convenience store must meet all the safety and quality requirements of any big city municipal system (assuming there are at least 25 customers plus staff daily). Assuming the water qualifies as “potable” already, the standard for ingredient water should also address the following “challenges” to serving high quality beverages profitably:
1. Reducing the most common off-tastes and odors
a) free chlorine (common, easy to remove)
b) “musty-earthy-fishy” T&O from microbes (common, easy to remove)
c) monochloramine (approx. 25% of major cities, more difficult to remove)
2. Reducing dirt, rust, turbidity, etc. for brilliant clarity, optimum carbonation and maximum
3. Reducing parasites such as Cryptosporidium oocysts
4. Inhibiting scale buildup in coffee-makers and ice-makers
a) fine-filtration plus “threshold” polyphosphate feed is usually sufficient
b) alkalinity reduction may be used only for the more severe cases
5. Controlling hardness and alkalinity for optimum post-mix quality (most carbonated drinks are
best if the ingredient water alkalinity is less than 150 ppm)
These criteria translate into the following basic, suggested minimum standards for ingredient water:
Turbidity……………………<0.5 NTU Taste & Odor……undetectable
Total Hardness……………<250 ppm Total Alkalinity……..<150 ppm
Iron & Manganese…………<0.1 ppm Total Chlorine………<0.5 ppm
Coliform Bacteria……………..absent Parasitic Cysts…………absent
In many instances this can easily be achieved with a single system comprised of just three components: a coarse prefilter, a bank of one to four precoat carbon filters, and a polyphosphate feeder following the filters, with a tee to coffee and ice service. Where disinfection is required, the basic system can be preceded by a chlorine feeder system and perhaps a bigger prefilter.
Where scaling is especially bad or the alkalinity needs to be reduced, an acidulant feeder or alkalinity reducer can be inserted in front of the equipment. Where the monochloramine level is very high or the water usage rate is very rapid, additional carbon beds or proprietary filters can be added to maximize adsorption. Beverage service managers should consult their beverage suppliers for other special requirements unique to their products.
This Technical Bulletin is courtesy of Pentair Everpure, Inc.