What About the Water?

Having been preoccupied with this question, its been a little while since I’ve written a post.

Water is naturally a huge part of a cup of coffee and the more and more we look at it the more it presents itself as one of the biggest players in a cup of coffees’ flavour.

We choose our coffees carefully, buying from roasters whose coffees we enjoy. On occasion we have really struggled with a few coffees. In these instances the coffees were not just a little flat or uninspiring, but were actively unpleasant.

The roasters we work with have always been receptive to feedback and keen to take part in a coffee dialogue, in the very rare instances when the coffees have been actively unpleasant, we’ve reached a difficult half way house where they are happy with the sample when brewed at the roastery, with there not seeming to be any of the same problems. In fact on these occasions they sound like different coffees altogether. After tasting coffee with them and trusting their judgment as they do ours, we were each taking part in a Sherlock-esque like hunt to find the culprit behind the nasty flavour transformation.

The increased ability to communicate about what and how we (any of us) are brewing, through the use of more exacting measurements, means it has become easier to rule out many parameters as the cause.

More often than not the clues lead to the same end – different water.

Can the water really be responsible for such a dramatic difference?

How often has the magnifying glass really been put on water? Sources such as the SCAA water book shed some light on the topic and we are all led to focus heavily on TDS (Total Dissolved Solids) as the measurement we should concern ourselves with, indicating that it is what has the biggest impact.

But what is TDS? A broad and vague measurement that indicates the total amount of minerals and particulates in the water beyond the pure H20. A brief look of bottled water labels will display that the number (TDS) can consist of largely different proportions across varying brands.

Would two waters with the same TDS, one in London and one in Bath, be the same? Would they impact on the coffee in the same way? What about the other numbers?

To explore these questions we were lucky enough to be able to enlist the help of theoretical chemist Christopher H Hendon. Chris has worked on varying projects with some focusing on taste products such as wine. He showed a keen interest in exploring water and coffee with us.

The resulting work has been fascinating and rewarding, with studies ranging from the use of atomic absorption spectroscopy, through to making the most of the U.K.’s largest super computer, as well as large blind taste testing data collection.

In order to fully present our piece on water and coffee, we need a different format to this blog. We are currently compiling an Ebook that will be released in the near future, I will make a note on this blog when the Ebook is released.