Seven Miles CSEC study shuts down espresso myth

A new study from Seven Miles Coffee Roasters and a leading Australian university has revealed a myth exists behind using designer water in espresso coffee.

Stripping down and manipulating the chemical balance in water is something widely done in elite coffee-making competitions but Dr Adam Carr of the Seven Miles Coffee Science and Education Centre (CSEC) and the University of New South Wales (UNSW) have revealed the practice may be moot.

“There’s a lot of noise in the industry about how water quality affects the espresso flavour, but few people have quantified what the changes actually are,” Adam says.

“This study examined how changes in pH, hardness, and total dissolved solids affected the concentration of five flavour compounds which generated bitter, nutty, chocolate, caramel and fruity flavours.”

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The mineral content in certain types of water was found to be the biggest contributing factor to taste. Hard water, which contains more minerals than soft water, was shown to be the best in terms of the depth and complexity of the flavours.

However, CSEC and UNSW also found that hard water’s benefits could be cancelled out by increasing the level of lime scale and mineral deposits inside coffee equipment and machinery.

CSEC revealed good old-fashioned tap water may be the best way to obtain maximum fulfilment from your morning coffee.

“I was surprised that the water coming out of Sydney Water’s treatment systems is nearly perfect for coffee, I wasn’t expecting that. The stuff coming out of those taps was great,” Adam says.

“The problem with stripping down water is that you remove a lot of its good qualities and our analysis has found that altering the total dissolved solids had little impact on flavour. It’s a popular practice in barista competitions for contestants to bring their own ‘designer water’ with added salts [but] why bother when Sydney Water does the hard yards for you?”

Seven Miles says the study, which will continue across the country later this year, could potentially revolutionise the way high-end coffee brewing competitions are approached in the future as well as people’s understanding of tap water’s role in making an espresso.

“We are going to try to extend [the study] to Brisbane and surrounding regions, Newcastle, the south Wollongong area and I’d like to extend it across to Perth as well,” Adam says.

“We’ve now established a benchmark for optimum water quality for espresso, which means we can go out into the field and troubleshoot water quality across Australia to help cafés identify if there are any water condition issues affecting the flavour of their coffee.”

Dr Carr also says using a simple filter may be the best way to eliminate general impurities from locally sourced water pipes.

He says going into the study with an open mind, no expectations and other industry experts were some of the keys to conducting the study that went for more than 10-months.

“From what I understand no experimental studies on this have been done [before]. There’s a couple of theoretical studies out there but there was no experimental validation and I think we’ve obtained that validation now,” Adam says.

“We put every single sample through an advanced analytical data collection system and graphed them to get the true trends. It’s as close to accurate and precise as you can get.”

Adam explains to BeanScene the information obtained will be used in Seven Miles’ world class coffee education programs.

“There’s so much that we can do because we have got some very, very smart people here so it’s nice to be able to dedicate the amount of time to the analytical banks,” he says.

“We’re integrating what we have found from water into our educational programs, so the research feeds the education.”

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