Brew · Hack · Technique · water · workshop · Zhng

Maxwell Colonna-Dashwood’s Masterclass on Water + Grinding

Papa Palheta has been bringing world renowned coffee consultant/roaster/baristas to share their knowledge and experience with the coffee community in Singapore. The previous class I attended more than a year ago was conducted by Scott Rao who authored numerous coffee ‘bible’ such as ‘The Professional Barista’s Handbook’, ‘Everything but Espresso’..etc.

Just about 2-weeks ago, Papa Palheta hosted a masterclass which was conducted by Maxwell Colonna-Dashwood who is the co-author of the book ‘Water for coffee’. Maxwell Colonna-Dashwood is also a U.K. Barista champion and blogs @


The full house masterclass was conducted in the ‘Cupping Room’, located on the 2nd floor of Chye Seng Huat Hardware.


Disclaimer: I’m neither a barista by profession nor a chemist, hence my interpretation of the class may not be accurate. I’ve however done research for a local research institute for over 10-years, and have some background in chemistry from maintaining saltwater aquarium for over 20-years πŸ˜›

On Water

The pie-chart shows the proportion of individual elements and processes relative to the effect they have on the end-result (taste) of the coffee. According to this chart, the quality of the green coffee plays the biggest role in the quality of the coffee, however the coffee can be destroyed by bad roast/brew/water. While there are many workshops on coffee brewing and roasting, this masterclass focuses on improving the taste of coffee assuming that the green/roast/brew methods are sound.


What do you understand about TDS?

The specialty coffee community has been following the water quality recommendation by the SCAA listed here, and perhaps the most ambiguous bit of that recommendation is the TDS level.

TDS (Total dissolved solids) merely indicates the conductivity level of the water, a filtered water has zero or near zero TDS because most of the ions andΒ minerals in the water have been removed. TDS DOES NOT indicate which are the ions and minerals presence in the water. In a way, reconstituting filtered water which reads zero on the TDS meter with un-filtered water to achieve the SCAA’s TDS standard does not ensure consistency in the water across different water source.

The following figures illustrate the point that water from two different sources can contain different minerals with varied compositions and yet registers the same reading on the TDS meter.Screen Shot 2017-04-27 at 12.35.02 pm

I have also noticed some have taken the TDS measurement of brewed coffee??

Having said that, TDS reading is still good for first-cut analysis to indicate how bad the water is, we do not want water with TDS reading of over 300ppm for example!! And a TDS meter can be very affordable at only ~SGD10 for the XiaoMi TDS pen.

And the recommendation? Filter everything (RO/DI + Carbon block) and re-mineralize the pure water. At the moment, Carbon block is the only filter I use for coffee brewing at home, and the TDS in my area hovers around ~80-100ppm.

And in a very short cheat-sheet point forms, these are the 3 most important components which alter coffee flavors that can be added to pure filtered.

  1. Calcium
    • Increases the mouthfeel
  2. Magnesium
    • Extracts more fruity note, malic acid from coffee
    • Magnesium sulphate can be used (Epson salt??)
  3. Bicarbonate buffer
    • Can be added post extraction/brewing to reduce acidity
    • Baking soda can be used

Though the recommended concentrations for each components are stated in the class / book, the real challenge is in dosing them correctly. It is probably an better idea to have those handy water test-kits (available in aquarium shop) before we go crazy with Epson salt and Baking soda.

Alternatively, capsules from Third Wave Water are available to re-mineralize pure water.

So what are water source in your cafe / home for brewing like? I like to hear! The following are some of the likely options.

  1. Filtered (RO/DI/carbon) water only
  2. Filtered water + reconstitution with (unfiltered water / some minerals)
  3. No filtering, i love coffee made with chemical-rich tap water

On Grinding

In the second masterclass,Β  Maxwell Colonna-Dashwood shared his insights on coffee grinding. A researched he conducted with Matthew Perger and a team of researchers. The research paper was published on, a prestigious scientific journal site.


Cool beans make better coffee

According to the research, chilled coffee beans when grounded produces more fines, as they can be broken to many more smaller pieces kind-of like how a colder solid object can be shattered to many more pieces. This also resulted in more even extraction due to the narrower particle size distribution of the coffee ground.


So what are the steps to replicate this experiment?

  1. Vacuum pack individual dosage of beans
  2. Chill the beans in vacuum pack to between -19Β°C to 20Β°C
  3. Grind immediately when the beans leave the chiller

Like most scientific publications, it can take many years or decade before the research can be widely adopted πŸ˜‰

Berg Wu surprised us last year with his winning WBC routine that involved chilled portfilter, breaking the convention that it has be kept warm at all time. Maybe we will start to see the shift in trend towards more ‘cold treatment’ as our understanding of coffee are constantly being redefined? Perhaps someone will put on good show with liquid nitrogen in the coming Brewer’s cup and WBC? πŸ˜‰


And my take away from this class

  1. Allow time for the grinder to cool before making the next cup
    • Can’t put a number on the time as there are too many variables
    • the point is to grind every dose with the same temperature
  2. Start the grinder’s motor before the bean touches the burr to ensure consistent grind speed (Emulate EK43 dosing model)

Overwhelmed? These are just a snippet of what was shared and discussed in the class. There were also cupping and book signing! Thank you Maxwell Colonna-Dashwood for sharing your insights so generously without reservation and Papa Palheta for the hardwork in organizing the masterclass for the local community! It was also a good catch-up with friends in the industries πŸ™‚


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