A cup of great coffee starts with the water. The spicy, earthy notes of a Sumatra are quickly masked by the pungent chemical taste of chlorine or the metallic bite of iron. Coffee is over 97% water, so commitment to water quality should be no less important than your attention to your beans, grind, and contact time. In a commercial setting, attention to water quality is absolutely critical. Water quality allows for the full extraction of the flavor notes from the coffee and ensures you are delivering consistent quality to your customers. A water filtration system will also protect your coffee and espresso machinery from being destroyed by scale, but retain enough mineral content to ensure proper extraction transpires during brewing.
What is the best water for brewing coffee?
The best water for brewing coffee is crystal clear, odor-free water with zero chlorine, a light amount of water hardness, a neutral pH of 7, and moderate mineral content (around 150 TDS). Water within these parameters promotes exceptional flavor extraction and full-bodied taste and smell. Since 98% of coffee is comprised of water, the water chemistry of your brew will leave a marked impact on the appearance, smell, and taste of the coffee. The presence of chlorine and chloramines risks tainting the coffee with an acrid chemical smell and aftertaste. If your water is too soft, the water won’t extract the subtle flavors of the coffee bean, leaving the brew with a flat taste.
The SCA (Speciality Coffee Association) has identified three key water quality factors that must be absent from the water in order to brew coffee. The water must be free from any aroma, color, and chlorine for the full taste, body, and smell of the coffee to emerge. In addition, they have set five standards for water chemistry necessary for brewing high-quality coffee. The levels of calcium hardness, sodium, TDS (total dissolved solids), pH, and total alkalinity must be monitored and fall within specified ranges. These standards are crafted by the SCA to provide coffee shops with metrics to ensure consistency and encourage coffee of superior quality and taste. The water quality standards, along with standards for water temperature, grind size, water-to-coffee ratio, and contact time make up what is known as the SCA’s “Golden Cup Standard” for brewing coffee.
Coffee and espresso filtration systems are water filtration systems designed to achieve ideal brewing quality. These filtration systems are formulated to solve the specific needs of commercial coffee brewers. Built-in scale inhibitors prevent damage to any espresso machines, why activated carbon blocks and KDF eliminate invasive contaminants that could pollute the rich taste and inviting smell of the coffee.
What needs to be removed from water for brewing coffee?
One of coffee’s most distinctive and inviting characteristics is its aroma. Studies have indicated the smell of freshly brewed coffee alone is enough to improve mood and performance in test subjects. To preserve that tantalizing coffee smell, all water used to brew coffee should be completely odorless. Chlorine, widely used to disinfect city water supplies, is notorious for imparting a stinging, pool water-smell on water. Hydrogen sulfide leaves water with a pungent, rotten egg odor. Phenol compounds in water can leave a medicinal, sickly sweet odor whereas bacterial presence can leave water smelling like decay. Obviously, any of these scents are enough to interfere with the fresh smell of coffee, not to mention repulse the coffee drinker.
Any odor-causing contaminant should be completely removed from the water before brewing. The pre-treatment of your water will depend heavily on the composition of your water, as different contaminants require different filtration approaches. If you’ve identified an off-putting smell to your water, start by conducting a water test. This detailed report will illuminate the source of the foul smell in your water.
Coffee should be brewed with water that is completely clear in color. Any cloudiness, discoloration, or tint should be eliminated from the water prior to brewing. This is both an aesthetic and a taste concern. Red or orange coloration is often indicative of the presence of heavy metals like iron, copper, or rust particles. This can manifest in your water from aging, corroded pipes and is prevalent in groundwater supplies. While these don’t necessarily pose health concerns, they can leave a metallic taste in the water as well as ruin the color of the brew. Sediment is extremely undesirable in the water, as it not only mars the color, it very likely could lead to a dirty or gritty taste.
To ensure you provide your customers with the mahogany-colored cup of coffee they expect, all water used to brew coffee should be totally clear. The most effective means of removing floating debris and particulate matter is through mechanical filtration. Sediment filters will sieve out any sand, silt, or dirt particles making their way into your water. Sediment filters are micron-rated to remove particles even past the limit of human visibility. Turbidity (the measurement of the loss of water’s transparency due to suspended particles) is easily solved by installing an inline sediment filter with a fine micron rating.
The contaminant that poses the biggest threat to your perfect cup of coffee is chlorine. Chlorine is a disinfectant commonly used by municipalities to eliminate bacteria and waterborne pathogens from drinking water. While it’s entirely safe to consume, chlorine is characterized by its sharp, unpleasant odor and its bitter chemical aftertaste. Any detectable level of chlorine will tarnish the coffee’s flavor profile with a harsh aftertaste and prevent the coffee bean’s unique flavor notes from translating onto the palette. To meet the SCA’s standards for brewing, the water cannot contain any traces of chlorine (0 mg/L) because of the overpowering negative consequences. If your coffee shop is on the city water supply, you will need to take steps to reduce the chlorine in your water.
Carbon filters are the water industry standard for eliminating chlorine from water. Through adsorption, the chlorine attaches itself to the expansive, porous surface area of the activated carbon. A carbon filtration system is a necessary component of any coffee house filtration system. The reduction of chlorine will ensure your roast’s character isn’t compromised by any chemical taste or smell.
Chloramines are an increasingly popular water disinfectant utilized by water treatment facilities. Chloramines are a more cost-efficient and longer-lasting alternative to chlorine and are created by the addition of both chlorine and ammonia to the water supply. However, chloramines are more difficult to remove and require extensive contact time with activated carbon for any significant reduction to transpire. Because of this, catalytic carbon is preferred for chloramine reduction. Catalytic carbon transforms the chlorine and ammonia into chloride, ammonia gas, and nitrogen gas. When sized properly, commercial catalytic carbon filters can eliminate chloramines from your water without compromising flow rates. Obtain a copy of your water distributor’s consumer confidence report to determine if your water treatment plant is using chloramines as a disinfectant.
SCA Brewing Standards for Water
The Specialty Coffee Association has outlined five optimal ranges for water quality to meet their “specialty coffee” standards. Widely used throughout the industry, these parameters give commercial coffee shops a template for ideal coffee brewing water quality. Each of these factors has a unique influence on the taste and the extraction process. When adhered to, these standards provide the perfect conditions for the flavor of your beans to flourish.
3-4 GPG (51-68 mg/L)
1-5 GPG (17-85 mg/L)
1. Calcium hardness
Calcium hardness is the measurement of dissolved calcium ions present in the water (as CaCO3, calcium carbonate). The total hardness of water measures both dissolved calcium and magnesium ions. Brewing coffee and espresso in water with low calcium content is recommended because minerals help encourage the extraction of flavor from the coffee and espresso grounds.
At elevated levels, water hardness is detrimental to commercial and residential plumbing. Calcium precipitates out of water to form a chalky white crust known as limescale. Pipes can become choked with scale and lose pressure. Water heating appliances will also become caked with scale, leading to increased energy usage and accelerated appliance failure. However, while calcium may wreak havoc on your machinery, coffee needs low levels of the mineral to achieve its well-rounded and bright flavor. Without calcium hardness, the coffee will taste flat. The ideal calcium hardness range for coffee and espresso is between 1-5 grains-per-gallon (GPG).
pH is the measurement of the acidity or alkalinity of a water-based solution. A solution’s pH is based on the concentration of hydrogen ions within the solution. The pH scale, ranging from 1 to 14, has a neutral value of 7. Though coffee itself is quite acidic, with an average pH level of 5, coffee brewing water should strive to maintain a neutral pH of 7 in order to maximize the flavors of the beans. The solubility of the water is determined by its pH. As the pH decreases, the water becomes increasingly soluble (meaning it is capable of dissolving more.)
The pH and respective solubility of the water has a direct impact on the taste of the coffee. When water is too acidic, the resulting coffee will taste astringent and bitter. If the water is too alkaline, the coffee will have a bland, dull taste.
The ideal level of sodium for brewing coffee is around 10 mg/L. According to the World Health Organization’s findings, most water supplies have lower than 20 mg/L of sodium present in their water. So, unless you are pulling water for your coffee house from a well, your water should not have undesirable levels of sodium.
However, sodium is very commonly found in commercial and residential water as a byproduct of the water softening process. While elevated levels of water hardness will ruin espresso machines and coffee brewers, a water softener will introduce far too much sodium into the water to be used for brewing. Though the sodium introduced to the water by softeners is neither a health concern nor detectable to our taste buds, sodium does influence how the tongue perceives sweet flavors. Since coffees hold delicate notes of fruit and rich dark chocolate tones, obtrusive levels of sodium can negate these subtle flavor profiles.
Softening water that’s too hard to pass through your equipment without injecting elevated levels of sodium comes down to carefully planning your water filtration system. Though a delicate balance to strike, it is a necessary one to achieve optimal water quality and serve delicious, flavorful coffees.
4. Total Alkalinity
The total alkalinity of water is a measurement of the water’s ability to resist change in pH. Though often conflated with pH, total alkalinity measures the concentration of negative ions from dissolved alkaline substances like bicarbonates and hydroxides. These ions are able to neutralize acids in water, protecting the pH from fluctuation. Unlike pH, total alkalinity is measuring the density of ions in parts-per-million (or milligrams-per-liter). pH is a scale representing the concentration of dissolved hydrogen ions in a solution.
In simpler terms, the total alkalinity is the water’s buffering capacity. It prevents the water from becoming too acidic. From pool maintenance to reef aquariums, many industries measure water’s total alkalinity to make sure that pH remains stable. For coffee brewing purposes, too great of alkalinity can interfere with extraction and ruin the taste. If the total alkalinity is too low, the water will not be able to absorb hydrogen ions and the pH will drop.
TDS (total dissolved solids) is the measurement of all minerals, salts, inorganic and organic matter, and ions dissolved within the water. Measured in parts-per-million, TDS includes everything from heavy metals, nitrates, and potassium to pollutants like fertilizer, road salts, and pesticides. Generally speaking, elevated levels of TDS indicate very hard water or contamination.
For the purposes of brewing coffee, low levels of TDS are preferred. Just like with calcium hardness, mineral content is favored for its beneficial effects on the extraction process and resulting taste of the coffee. However, while the EPA recommends drinking water register below 500 ppm of TDS, the SCA recommends TDS around 150 ppm for commercial coffee brewing purposes. Water with a TDS of 500 is far too hard to brew with, and the abundance of dissolved minerals and metals will cloud the taste of the roast. Water with a TDS of 0 is too flat to brew coffee with, and its lack of character will translate into a boring cup of coffee.
How do I protect my coffee brewing equipment from scale?
Taste is not the only consideration to make when investing in a water filtration system for your coffee shop. While low levels of water hardness and TDS are encouraged to bring out the full character of your roast, mineral content can cause serious damage to your commercial brewers and espresso machines. Hard water (water characterized by high calcium and magnesium content) creates limescale build-ups in appliances. Scale deposits will coat the interior of your brewing equipment with a crusty, white layer. The scale will diminish the machinery’s performance, damage the heating elements, and over time, destroy equipment entirely. This means out-of-service machinery, expensive repairs, and premature replacement costs. These costs can be very damaging to a business and interfere with your daily operations.
This presents a rather unique problem. Traditional methods of hard water treatment (namely water softening) eliminate the entirety of the calcium and magnesium from the water, replacing them with sodium ions. Depending on how hard your water is, this would result in mineral-free water with sodium ranges far exceeding the brewing standards. To reduce the sodium, the water should be treated by reverse osmosis, a water treatment process that will reduce your TDS levels to near zero. Once again, this diminishes the characteristics of the water that aid in developing the nuanced tasting notes in your coffee.
Commercial food and beverage water filtration companies like Everpure have created multi-stage blending filtration systems that solve this dilemma. These filtration systems soften, buffer, and polish the water for your espresso and coffee machines. These commercial coffee and espresso filtration systems pass the water through carbon and sediment filters, eliminating chlorine and particulate matter, before passing them through a bed of softening resin. However, unlike traditional water softeners, these systems use a “weak acid” cation ion exchange process. The resin replaces the calcium and magnesium ions with hydrogen ions instead of sodium. However, to maintain the TDS and calcium hardness, some of the water from the carbon filter bypasses the softening cartridge. The water is then passed through a buffering agent, which prevents the pH from dropping and the water becoming too acidic.
What is the best commercial filtration system for coffee?
All commercial coffee shops should use water filters that eliminate chlorine and sediment from their water while preserving low mineral levels and maintaining a neutral pH. Depending on the source and chemistry of your water, you may require a more extensive filtration system to achieve optimal water quality. There’s never a one-size-fits-all solution when it comes to commercial water filtration, as your water quality, flow rate, and water pressure will all dictate the scale and design of your solution.
One of the simplest ways to dramatically improve your coffee brewing water is to install a carbon filter. When it comes to ruining the taste of coffee, chlorine is the biggest offender. The chemical disinfectant suppresses the natural aromatics of coffee. The robust, full-bodied smell of freshly brewed coffee is masked by chlorine’s unpleasant bleach smell. Chlorine will subdue the coffee’s tasting notes, preventing any floral, citric, or herbal tones from landing on the customer’s palette. Frankly, it’s impossible to brew a great cup of coffee if there’s any detectable level of chlorine.
Carbon filters are excellent filters for removing chlorine from water and improving the taste of water overall. Through adsorption, chlorine particles adhere to the porous surface of the activated carbon, restoring the clarity of its taste and smell. Carbon filters also trap other organic pollutants, like trihalomethanes, VOCs (volatile organic compounds), and are often designed for the reduction of contaminants like lead, cysts, and asbestos. Most specially-tailored commercial coffee and espresso filters employ activated carbon cartridges (or substitute another chlorine-reducing media like KDF). Carbon filter media is typically made from wood-burned carbon granules or environmentally-friendly charred coconut shells. They come in dense carbon blocks, which boast extraordinary surface area, or as granular activated carbon, which allows for quicker flow.
The carbon filter best suited for your commercial space will depend on your flow rate, water demand, and how much chlorine is in the water. Carbon filters can be installed inline with your water line in 10” or 20” filter housings, depending on the size of the filter. Other carbon filtration systems use loose media stored in a tank, and treat the entirety of the water entering the building. Some systems, designed specifically for coffee or espresso filtration, can be installed directly in front of the water lines carrying water to the brewing equipment. Most carbon filters can effectively reduce contaminants for anywhere from 6 months to a year, though their lifespan will depend on factors like the amount of water filtered through them.
Explore more about how carbon filtration works.
While most carbon filters have a fine micron rating capable of removing sediment particles, sediment filters are a crucial element of any water filtration system. Sediment filters do not only extract particulate matter from the water, but they also prolong the lifespan and increase the efficiency of all other water filters. If a carbon filter is tasked with mechanically removing pieces of silt and grit from the water, its pores will become clogged with debris and the filter will be less effective at removing the taste-fouling contaminants like chlorine.
Installing a sediment filter directly before a carbon filter provides double the filtration power. Sediment filters can catch debris smaller than a micron, increasing the performance and lifespan of the carbon filter. A sediment filter allows your entire water filtration system to operate smoothly. Sediment filters also ensure your water is clear from any particles that could lead to water discoloration, one of the key standards to meeting the SCA’s guidelines.
Learn more about how sediment filters work.
Coffee and espresso filters
One of the best options for filtering the water in your coffee shop are systems designed specifically with coffee and espresso brewing applications in mind. These systems eliminate contaminants like chlorine and sediment while also protecting your brewing equipment from being destroyed by scale. As previously stated, scale will devastate your machinery, leading to pricey repairs and out-of-service equipment. These filters come in a host of styles, with some of them boasting half-micron ratings capable of reducing cysts and high turbidity. Others utilize proprietary buffering agents to ensure the pH doesn’t plummet too far past neutral.
Some of these systems employ phosphate as a scale inhibitor. The phosphate is usually incorporated into a carbon block. The phosphate captures calcium carbonate, preventing scale from proliferating within the machine. Others use softening resin cartridges with weak one-way acids to reduce the total calcium and magnesium within the water. However, they do not completely eliminate the water hardness (allowing for that desirable low level of mineral content), nor do they use sodium-based ion exchange to soften water. Traditional water softeners add an unpalatable amount of sodium to the water. Since sodium influences how the tongue perceives the taste of sweet and salty flavors, elevated levels of sodium in the brewing water will tarnish the overall flavor of the cup of coffee. Instead, these filters use deionization media, which exchanges the mineral ions for hydrogen and hydroxide ions. The softening cartridge is also located after the carbon filter, and some of the water from the carbon filter is allowed to bypass the softening media. This additional precaution makes sure there is sufficient mineral content in the filtered water.
In addition to scale prevention, some coffee and espresso filters are designed to reduce chloramines. If chloramines are present in your water, it’s important you find a system rated for chloramine reduction to restore the taste and odor of your water. Left untreated, chloramines will impart that dreaded chemical taste and odor onto your coffees.
What is Third Wave Water?
Third Wave Water is a mineral blend specially designed to give coffee-brewing water increased calcium, magnesium, and TDS. Popularized after appearing on Shark Tank and winning the backing of Barbara Corcoran, Third Wave Water presents itself as the answer to the java lover seeking an elevated cup of coffee. Their proprietary blend raises the mineral content, TDS, and sodium levels to SCA standards without chemical additives or artificial ingredients. They manufacture two mineral blends, one tailored specifically for brewed coffee and one for espresso. By adding this mineral blend to store-bought filtered water, you can achieve perfect coffee water quality.
While Third Wave Water is an excellent way to create high-quality water profiles in your kitchen, it is wildly impractical for any larger application. First, the water the blend is added too must be filtered already. Third Wave Water only works if the water has been distilled, de-ionized, or treated by reverse osmosis. Third Wave Water only enhances a neutral water profile, it is not a substitution for filtration. In a commercial setting, it would be incredibly difficult and inefficient to prepare each batch of water prior to brewing coffee or espresso. Though Third Wave Water offers a perfect mineral balance in a convenient package, this solution only works well for homes or offices. In a commercial setting, it is far easier to create the ideal water profile by setting up your own coffee water filtration system.
What’s in Third Wave Water?
Third Wave Water uses a blend of calcium and magnesium crystals to enhance the body and flavor notes of the coffee. The balanced alkalinity of the blend ensures that the coffee doesn’t become too acidic. The Classic Profile adds low levels of sodium, to give brewed coffee a brighter taste. This accentuates the coffee’s more delicate notes. The Espresso Profile adds potassium bicarbonate to buffer the alkalinity of the water. Espresso shots are pulled through grounds much faster and at a higher temperature than brewed coffee. The added alkalinity ensures the grounds are able to make adequate contact with the minerals as the espresso shot is being pulled.
Can I use reverse osmosis water to brew coffee?
Reverse osmosis water is not suitable for brewing coffee. Reverse osmosis water lacks the minerals that give coffee its distinctive character and extracts the unique flavor profiles from the coffee grinds. While the water reverse osmosis produces is of remarkable purity, the taste of coffee is elevated by the presence of dissolved solids and calcium and magnesium. Reverse osmosis water also tends to be mildly acidic, with a pH around 5-6. This is too low for the purposes of coffee brewing and will make your coffees unpleasantly sour. Furthermore, the 0.025-micron pores on the reverse osmosis membrane eliminate virtually all TDS from the water. To brew great coffee, some TDS content is necessary to allow the flavor notes to emerge.
While reverse osmosis is popularly used by breweries, hydroponic farms, and aquariums, these applications tend to use highly pure water as a building block. Different hydroponic crops favor different concentrations of nutrient solutions, all of which can be built out of the treated RO water. Breweries use RO water to craft minutely controlled recipes, adding in the exact amount of chlorides, sodium, and carbonates they desire. A great cup of coffee doesn’t require such precise water chemistry control. While it must be clear, chlorine-free, and fairly soft, there are many ways to achieve this without reverting to reverse osmosis.
If you have decided you want to use reverse osmosis for your commercial coffee production, find a system with a remineralization post-filter. This passes the water through alkaline-rich media, raising both the alkalinity and the pH of the water. This protects the water from being too acidic for proper brewing, as well as reintroduces some of that necessary mineral content back into the water.
It’s also worth noting that reverse osmosis produces water very slowly. This is not a problem in applications like breweries, where water can be stored and then treated with the appropriate minerals and ions. However, for a coffee shop that plans on brewing fresh coffee throughout the day, you will need sizable storage tanks to ensure you always have access to treated water. You’ll also want to make sure that you’re equipped with the correct booster pumps to maintain water pressure, as you don’t want the water pulling through the espresso or coffee grounds too slowly.