- How to Master the Art of Making the Perfect Cup of Coffee - https://density.coffee -

Ground breaking research

Excuse the terrible pun.

I want to thank Logan Collinge of Mojo The Beanery [1] for spending several weekends roasting to order for me, and being such a mine of information.


The first experiment was to take one single origin green bean, and have Logan roast it to common roast levels across the roast spectrum.

The selected Green Bean was a Guatemalan – El Coygoyal, with the following roast levels:

  1. Light City
  2. Half City
  3. Cinnamon
  4. Medium
  5. City
  6. American
  7. Breakfast
  8. Dark
  9. Full City
  10. Vienna
  11. Darker than dark

This enabled me to test, extend and refine the computer model.

Testing was making two cups of coffee at a time, A/B. One using the predicted model settings, the other cup shifted up or down the SSDI [2] scale, or varying one parameter e.g ratio. Taste testing used my partner, and various long suffering work colleges, to gain opinions other than my own. Both espresso and filter methods were tested. Testing also was done over the period of a couple of months, to determine the optimum age after roasting for each roast point.

The experiment had to be repeated a second time. This time using specific drop points to fill in some data gaps. A different Single Origin Coffee, a Brazillian – Sito Pedra Menina was used.

  1. 187
  2. 191
  3. 196
  4. 205
  5. 210
  6. 219
  7. 225
  8. 230
  9. 240

The results formed the Rules of Thumb, which is the 150 data point scaffold of the full 5000 data point SSDI [2].

This process taught me an awful lot about how to make the best of any roast point. I was amazed to find I could actually make an enjoyable cup of coffee right across the range. It was instrumental to developing the SSDI [2], so many thanks Logan!

author avatar
richard.c.mayston Solution Architect
Under-extracted coffee is sour, and over-extracted coffee is bitter. Different degrees of extraction are required for different roast levels, which correlate most strongly with density. The density.coffee recipe series is a practical tool that empowers you to navigate by taste and resolve sour or bitter coffee issues. It provides a full range of extraction tools for any method of coffee extraction, putting you in control of your coffee's flavor.