June 14, 2022

How can baristas maximise water quality & consistency?


Around the world, specialty coffee baristas rightly focus on tweaking extraction variables to brew delicious beverages. However, as important as grind size, dose, and yield are, baristas must also pay close attention to another essential brewing variable: water.

Around 98% of every cup of filter coffee is water, making it an integral part of the process. This means that as well as using great coffee, it’s also important to use high-quality water.

Even the most experienced baristas will struggle to make an amazing cup of coffee with imbalanced water. So, how can you make sure you’re using the right water to brew coffee – in both coffee shop and competition settings? 

I spoke to two experts from water filtration solutions brand Pentair to learn more. Read on to find out what they told me.

You may also like our article on maximising water quality & consistency in your coffee shop.

brewing french press coffee

Why is water quality so important for coffee?

Salvatore Di Festa is the Mediterranean Countries Sales Manager for Pentair.

“Each cup of coffee can be up to 98% water, which means water will influence the flavours in your coffee,” he says.

First and foremost, you need to make sure that water is safe to consume. “Heavy metals and other contaminants could have negative effects on human health,” Salvatore adds.

Moreover, water contains a number of minerals and compounds, some of which are soluble in coffee and can affect the final cup profile. These include magnesium, calcium, and carbonates. An imbalance of these minerals and compounds will result in under or overextraction.

Matteo Colamartino is the Product Manager for Pentair.

“[For baristas], focusing on [coffee quality is important], but [it can be affected] by low water quality,” he explains.

The two key variables that baristas need to understand when filtering water for brewing coffee are water hardness and water purity. It’s important to note that both of these will vary based on geographical location.

Water hardness can be broken down into total hardness and carbonate hardness. The first is a measurement of the calcium and magnesium levels in the water. Balanced levels of both are essential for optimum extraction, but too much or too little can hinder it.

“With Pentair’s water filtration systems, baristas are able to obtain the optimal balance of calcium and magnesium levels,” Salvatore says. “This also helps to protect the machine [from limescale build-up].”

Carbonate hardness, however, is a measurement of how many carbonates and bicarbonates are present in water. These compounds are especially important for extraction, as bicarbonates act as acidity buffers. Essentially, if the amount of bicarbonates in water is too high, many of the coffee’s flavours will be muted or otherwise reduced.

“The Specialty Coffee Association (SCA) has a set of defined optimal water specifications, including total dissolved solids (TDS), total hardness, carbonate hardness, and pH level,” Salvatore tells me.

The SCA recommends using clean, odour-free water with a total hardness between 50 and 175 parts per million (ppm) and a carbonate hardness between 40 and 75 ppm. The ideal pH range for brewing water, meanwhile, is between 6 and 8.

brewing espresso

How can water filtration systems benefit baristas?

In their day-to-day job roles, baristas have to focus on a number of different extraction variables – including dose, yield, brew time, and grind size, to name just a few.

Although baristas should also account for water quality and hardness, water filtration systems can help to expedite the process – especially when more complex extraction variables are concerned. 

This means that baristas can focus more of their attention on other brewing variables, as well as providing excellent customer service.

“Baristas need to trust that their water [quality and hardness levels are optimal for brewing coffee],” Matteo adds. “Pentair Everpure filtration systems [can handle a range of water hardness and quality levels], as well as providing consistent results throughout each use.”

Meanwhile, Salvatore notes: “The better your water is, the better your coffee will be. This is why so many baristas depend on water filtration solutions, like Pentair, to consistently serve high-quality coffee.”

How do these systems work?

“A good water filtration system will do two things: protect the equipment and create the optimal mineral composition in the water to extract desirable flavours from the coffee,” Matteo explains. 

Salvatore tells me about the ion exchange technology used in Pentair’s Claris Ultra, and how it helps to soften water. 

If water is hard, it contains high levels of magnesium, calcium, and carbonates. While higher levels of these minerals and compounds can help extraction, if the levels are too high then extraction can be affected.

“Filtration systems such as the Claris Ultra mainly optimise levels of calcium, magnesium, and other carbonates, which are the main cause of limescale,” Salvatore says.

If both total hardness and carbonate hardness are too low, the coffee will underextract and taste weak. If total hardness increases, but carbonate hardness remains low, the flavours in the coffee will be heavy and dull.

Conversely, if carbonate hardness is too high but total hardness is too low, the coffee will taste chalky and flat. When both carbonate hardness and total hardness are too high, the coffee will easily overextract – and end up tasting bitter and dry.

Other water filtration systems, such as reverse osmosis (RO), allow baristas to tweak and customise water mineral composition to more specific parameters. Water passes through a semipermeable membrane at high pressure, which removes minerals to meet the required levels.

Many coffee shops use RO filtration systems, as they are widely considered to be the most effective way to achieve optimal water hardness.

barista at a competition

Water quality and consistency in coffee competitions

Although water hardness and quality are essential variables for baristas, they are understandably under much more scrutiny in coffee competitions, such as the World Coffee Championships. 

Competitors at these events are doing everything they can to bring out the most vibrant and unusual flavours in their coffee, which makes the margins for error much finer – including when water quality is concerned.

“Competitions are where [the brewing variables are scrutinised] to the highest levels,” Matteo tells me. “Every single detail is important.”

In the past, many competitors at these events used bottled water. Although the mineral composition of bottled water is often more balanced than tap water, it is not necessarily perfect.

As a result, water quality at the World Coffee Championships has been a much bigger focus in recent years. Competitions now provide competitors with filtered water through sponsorships with water filtration companies, so baristas can focus on brewing high-quality coffee and highlighting their skills.

Pentair is the sponsor for the 2022 World Coffee in Good Spirits competition, World Latte Art Championships, and the World Roasting Championships, which will all be held at World of Coffee in Milan from 23 to 25 June.

“These competitions take place in a different location each year,” Matteo explains. “This is important to note, as different geographical locations have different water compositions.”

Standardising water hardness and quality ensures a level playing field in these high-calibre coffee competitions, as all competitors from different countries will use the same water. This allows the judges to solely focus on each individual’s technical skills.

“[Pentair’s water filtration systems ensure] that water quality is in accordance with SCA parameters,” Salvatore says. “[This helps] to guarantee consistency during the competition, [which puts all competitors on a similar level of water quality].”

pour over kettle

Understanding different types of water filtration systems for competitions

As coffee competitions, such as the World Coffee Championships, are so high-level, the most effective water filtration solutions should be used to achieve the best results. This generally means using RO systems.

As part of its sponsorship, Salvatore tells me that Pentair will supply high-efficiency RO systems for some of this year’s World Coffee Championships events. Salvatore explains that Pentair’s RO system works by initially passing water through a semipermeable membrane, before then prefiltering the water that competitors will use. 

“Despite there being different water quality in different competition locations, we are able to supply consistent, optimal water quality in the most sustainable way,” Salvatore says.

He explains how Pentair’s filtration technology also helps to decrease waste.

“Any RO system will waste some volume of water,” he says. “However, Pentair’s RO system is around 80% efficient, whereas more traditional systems have an efficiency rate of around 20%.

“This means that while traditionally, four litres of water are wasted for every one litre of water produced, Pentair’s RO system only wastes 20cl per litre.”

brewing pour over with clean water

Consistently high-quality water will always be essential for brewing amazing coffee, whether you’re behind the bar in a coffee shop or standing on stage at a competition. 

No matter how high-quality your coffee is, ensuring that your water is within the optimal hardness ranges is just as important. The first step is testing it – you can check out local authority websites to see if there’s any guidance on water quality in your area, or buy a simple self-testing kit online. 

Enjoyed this? Then read our article on how you can make water perfect for brewing coffee.

Perfect Daily Grind

Please note: Pentair is a sponsor of Perfect Daily Grind, and will be at stand H3-K10 in Hall 3 at World of Coffee from 23 to 25 June 2022.

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