About 5 years ago I started writing stuff on this blog, and in less than a month an invoice will come to renew the domain registration and to pay for another year of hosting, which I will be declining to pay.

The blog has served its purpose, but it no longer has a purpose.

In the 5 years since I began writing I have transitioned from being a heckling coffee hobbyist, to someone who works not in the coffee industry, but in a closely related industry, and with a company for whom coffee is a core focus. In some way, oddly, this blog has helped facilitate that. It gave my loud mouth an undeserved soapbox, it introduced me to a whole world of people, many now friends.

I can’t say that I look back fondly on all that I have written.

As a collective (coffee geeks/specialty industry talking heads / starfuckers and starfuckees) we lend too much credence to unbridled theorists. The positive reinforcement from comments, retweets, attention perpetuates this kind of malignant behaviour. It becomes self-fueling, and unfortunately (or fortunately depending on your point of view) it can be rewarding in a roundabout way.

Thought is cheap though. Developing a compelling, yet ultimately shallow narrative is also cheap, and easy (see most TED talks). Action, work, making something, creating change is much more difficult and often less heralded. I hope to do more of the latter and less of the former.

The eulogy probably deserves a more positive conclusion, so I will leave it to the videos embedded below to elevate the gaiety.



Fergus tells it like it is from David Walsh on Vimeo.

Requiem for Atlanta (VacPot of Glory) from David Walsh on Vimeo.

2009 Irish Barista Championship from David Walsh on Vimeo.


Taste Preference Study Data

I have been remiss at publishing this data in a timely manner.

As promised, for anyone interested the data is available here.

The data was presented in a digested form at the Nordic Barista Cup last year, see here.

The slides from that presentation can be downloaded here – DW-NBC12b.

Thanks again to everyone who participated, and to those who helped.


phase 2


For a little over 2 months participants in this study have been making and rating coffee beverages, measuring TDS and submitting data online. In that time a couple of hundred samples have been collected. Samples are still being submitted, albeit at a much slower rate than in the beginning.

Participation has until now been limited to individuals with access to a coffee refractometer. In a way this is what makes that study so beautiful, my job is merely to compile the data at the end. The collection is self-sufficient, the only exertion is on the part of the particpants.

That said, owners, or frequent users of refractometers are hardly an unbiased group. They are undoubtedly an interesting group, but they may have preconceived ideas based on their familiarity with measuring/tasting based on extraction and strength. With that in mind, I want to introduce the second phase of this research series. Here’s how it will work:

  • Initially 50 participants can take part (on a first come first served basis).
  • Participants will receive via post a sample kit, containing 6 coffee sample tubes, 2 syringes, 6 syringe filters, 1 brew water sample tube, written instructions, and a paper form.
  • Participants will be asked to record ground coffee weight, final beverage weight, and taste score for 6 separate brews within a 7 day period (this will require a scale with a minimum 1gram resolution).
  • A 15ml sample from each brew will have to be prepared (instructions below).
  • Participants will be required enter the recorded values in an online form.
  • Participants will be required to return the 6 coffee samples, and 1 brew water sample to one of 5 measuring locations.
  • Participants will receive the results of their samples after they have been measured.

Based on the success of the initial 50/pilot, this study may be expanded in the future. The incentive for participants here is that they get a chance to get some reference points for extraction using their own equipment. I would therefore encourage participants to use their 6 samples wisely and to vary their grind setting, coffee/water ratio, and/or contact time. In that way the results they receive back will be of more value (it is also of more value to the study to have a wider spread of data).

If you wish to participate please fill in the form below (PLACES NOW FULL).

Note you must own a scale with at least 1g resolution. You must also commit to promptly return sample tubes by post.

I want to thank VST and Marco for their generous support and contributions to this study. I also want to thank James Hoffmann, Ben Kaminsky and Emily Oak who have kindly offered to accept and measure sample tubes returned to them by post. In addition to those three, sample tubes may also be returned to Vince Fedele and to myself.



paper form for research

Big thanks to Jessica McDonald from Square Mile on this.

I popped into the Square Mile Roastery a couple of weeks ago, and they had a clipboard with this sheet on it to record all their brews to enter into the research thing we’re doing. It’s a blindingly obvious (why didn’t I think of that) kind of thing, so very closely based on their design – here is a form for anyone else to use…

(just have to remember to enter the data online later!)



disseminating coffee research(ing)

The SCAE Gold Cup Research programme, which I have discussed previously, is a timely piece of work, but also a massive pain in the arse. I applaud the SCAE for undertaking this endeavour, as it is an ungainly, painful operation to run. It has been conducted 4 or 5 times at various locations around Europe now, I’ve been involved with 2 of those, and it’s no easy task. You have limited time to dial in, sometimes with unfamiliar equipment. Not to mention the difficulty in deciding on one coffee which should represent all coffee.

The scope of the research is to determine taste preference across 5 different levels of extraction, with strength being constant. That in itself would be good to know. However, it isn’t designed to cover the entire landscape of coffee brewing. It would be utterly impractical to do so, given the limitations of resources and time afforded to the study.

What if there was an easier way?

This kind of study needs several things, first off data, lots of it. The more data acquired the more powerful the results. It needs sensory evaluation of coffee made to a known recipe and of a known strength (extraction can thus be inferred).

There are thousands of users of VST refractometers around the world. Most probably brew coffee everyday. If each of these users submitted only one measurement to this study we would have a significant, useable sample size. If some of these users submitted multiple measurements over the course of a few months, we could have a huge, powerful sample size.

So, here’s what I am proposing. Anybody with a refractometer can (and should) submit data to this study.

Using a simple form, submit the recipe, the TDS/strength, and a score (your evaluation of the brew).

This approach has its pros and cons.

  • It gets around the need to pick one coffee. Now it is every coffee or any coffee.
  • It potentially allows for a much wider coverage of the brewing chart.
  • It could allow for a large number of samples to be acquired in a short amount of time, with minimal effort.
  • There will be inherent variability between users, in how they brew, and how they measure, and how they score. There will inevitably be some bad data. However, given a large enough sample size you would hope this would even out.

I would envisage this running for about 6 months, at which time the data would be published and freely available for anyone to use/analyse.

The following is the suggested protocol (I thank Vince Fedele for his help on this).

  • Measure (by weight) and record your ground coffee and your brew water.
  • Transfer a small sample (4-5g) from the brewed (& filtered) coffee to a cool glass/cup.
  • Draw sample into pipette/syringe, expelling as much air as possible, leaving the tip submerged in remaining sample. Do not measure at this time.
  • Evaluate coffee over your normal range of drinking temperatures, choose score based on scale below.
  • Remove pipette, discard a few drops, then transfer to sample well and measure as normal.

If anyone has thoughts on improving this experimental design please leave a comment below. The basic intention of the steps here is to allow the participant to taste the coffee without being influenced by the measurement. Therefore it is key to try to prevent erroneous readings due to evaporation over time.

The form can be found here (on this blog) – or here standalone.

I suggest iPhone users follow this guide to add a shotcut to their homescreen for frequent use.

The scale used for evaluation is a 9 point hedonic scale similar to this: