Beverages: the bitter truth about hard and soft water

29 October 2015
Beverages: the bitter truth about hard and soft water

Hard and soft water affect the taste of coffee and tea and decrease the life of beverage machines. Ian Boughton discovers the best solutions on the market that don't indulge bad science

Water quality presents two very big hazards to the hospitality trade. Water with high mineral content scales up brewing equipment at an unhelpful rate and repairs are expensive. It also affects taste, sometimes unpredictably.

Nobody really knows where the answer lies. Coffee roasters and tea blenders recognise the problem and Taylors of Harrogate recently devised a 'hard water' version of its Yorkshire Tea. But, although it has been regularly suggested, there have been no meaningful discussions between the beverage trade and the water industry.

There are, of course, many water-treatment and filter products, but these vary from the scientifically reputable to what have been called 'smoke and mirrors', with some suppliers accusing their rivals of bringing 'false science' into the market.

The single thing on which everyone is agreed is this - every business serving tea and coffee should know what kind of water is coming through their pipes. Many coffee houses already test their water with a simple digital instrument every few days because, as one coffee roaster has said, "you have to know what water you have to know how to brew it."

The importance of this, says European WaterCare (EWC), is that if waters are so different, then no salesman's off-the-peg solution is likely to be the right one - there is a big difference between a supplier who wants to promote one kind of product and a company which is willing to discuss with a caterer how the local water affects the house beverages.

A reasonable generalist assumption, says EWC, is that every business serving hot beverages is likely to need treatment of some kind to regulate their water quality. An absolute requirement is that every beverage manager should test their water, to see what they're working with. No beverage manager can assume they know what their local water is like, because a lot of water, is moved around the country now, and areas that may previously have had soft water may now have hard water.

Marco Olmi at the Drury Tea and Coffee Company makes the same point: "At one time water in north London was different from water in south London, but now we have the ring main. People in areas who had soft water and needed no protection are surprised to find they now do!"

Educating and informing

"One of the biggest ongoing challenges is the knowledge and perceived benefits of different technologies available to treat water," says EWC. "Our goal is to create a training and development centre of excellence, to provide a platform for a better understanding of water.

"In addition to making our own products, we do supply and endorse technologies used by other brands… although we are competitors, our aim is to educate and inform customers on the technologies which work and which don't."

General agreement comes from Brita, where sales director Miles Dawson points out that over 60% of the UK has local 'hard' water, and that over two-thirds of beverage machine breakdowns are caused by scale. Scale can increase energy costs dramatically, because it acts as an insulator around heating elements in water, so more energy is needed to bring the water up to temperature.

Brita has worked on the water filtration for recent international barista contests, and reports that similar problems apply internationally - in recent contests in Italy, it had to do a lot of work with the hard water to create the approved conditions for a contest.

In the UK, it acknowledges that baristas are among the best practical experts on the subject, and Brita has now worked with the well-known coffee gurus Rob Dunne and Victor Frankowski to create training sessions to show beverage managers just how much the quality of water affects their coffee.

"In the coffee community, the water is no longer taken for granted," notes Miles Dawson. "Our sessions aim to equip operators with a meaningful, in-depth understanding of this."

It is always better to analyse a business's house water supply than to buy an off-the-shelf filter product, says Stuart Godfrey, business development manager at Aqua Cure. "Too often we hear that operators are fitting one filter across their whole base, working on poor advice."

And if a filter designed for hard water is used in a soft-water situation, he adds, the result is a different problem - this can cause the water to become too acidic, leading to corrosion inside brewing equipment, split heating elements and pin-holes in internal metal surfaces. "The cost of controlling water quality is very little compared to the cost of descaling, repairs, down-time and lost revenue."

While many products work on the resin-filter process, a popular system in coffee houses is reverse osmosis (RO) purification. Some say this is the only answer to very hard water.

The 3M brand has done a lot of work on RO, and business development manager Richard Scorer says that in the right situation, this method has benefits: "Ours has a blending function that allows you to set a specific total dissolved solids (TDS) level We have worked with various speciality coffee houses and have seen baristas adjusting the TDS to optimise a specific roast of coffee, something which 'normal' filters would not be capable of doing."

Whichever water-treatment solution you choose, says Paul Proctor of EcoPure Waters, think the subject through. Treating mains water well can give you an opportunity to sell your own-brand bottled water, providing an additional revenue stream.

Mineral content

Hard water has a high mineral content - it is not harmful, and scientists say it even counts as a dietary supplement for calcium and magnesium. However, in brewing equipment it forms scale deposits that clog plumbing.

Water hardness is expressed as 'parts per million', and it is often said that 150ppm is the optimum amount for coffee. The British Drinking Water Inspectorate says that drinking water in England is generally 'very hard', with most areas, particularly east of a line between the Severn, rated at above 200 ppm.

Water is mostly hard in urban areas, but Manchester and Birmingham are exceptions, being 'soft' because of the reservoirs from which they draw their water. Much of the south west is 'soft', but Bristol has areas at 228.5 ppm. London water is universally criticised at around 275-300 ppm, but it is not the hardest - in Norfolk the rating is 332, and coastal Suffolk has been rated at 400ppm.

The water book

An authority on water for hot beverages is the UK barista champion, Maxwell Colonna-Dashwood of Colonna and Small's in Bath. Like other baristas, he had often wondered why great coffees brewed well in some conditions, and at other times were "not just a little flat, but actively unpleasant".

Maxwell Colonna-Dashwood and Christopher Hendon

Working with chemist Christopher Hendon of the University of Bath, he has published a paper and book showing that the beverage trade's received wisdom about water has been too simplistic, and that 'hard' water is not the entire problem - it is the type of hardness that matters.

"The discussion of 'hard' water and 'soft' water is flawed, as it does not recognise that two waters of similar hardness or softness can still be very different," he says.

Water For Coffee, £26.99, is available at

Reverse osmosis

The reverse osmosis (RO) treatment has been touted by some salesmen as a magic cure, but opinions differ. It works by removing all, or a very high percentage of, contaminants - so much so that it is common to 'blend back' some untreated water to bring the 'parts per million' reading back up to 50-150.

RO is said to be good for a kitchen where several pieces of equipment are located together, saving the need for resin filters on each item. It is also claimed to be consistent.

Water is wasted during the RO process, but in theory this can be diverted for washroom use. It is also a relatively high capital cost, and a shop owner who did blind taste comparisons using filtered water and RO-treated water discovered that customers preferred the drinks made through traditional filters. The jury remains out.


European WaterCare

3M Purification


EcoPure Waters

Aqua Cure

The Caterer Breakfast Briefing Email

Start the working day with The Caterer’s free breakfast briefing email

Sign Up and manage your preferences below

Check mark icon
Thank you

You have successfully signed up for the Caterer Breakfast Briefing Email and will hear from us soon!

Jacobs Media is honoured to be the recipient of the 2020 Queen's Award for Enterprise.

The highest official awards for UK businesses since being established by royal warrant in 1965. Read more.


Ad Blocker detected

We have noticed you are using an adblocker and – although we support freedom of choice – we would like to ask you to enable ads on our site. They are an important revenue source which supports free access of our website's content, especially during the COVID-19 crisis.

trade tracker pixel tracking