It's really important to us here at Dog & Hat that we provide the very best service to all of our members, and to help us achieve this we invest in the highest quality training.

Last year, we started the SCA (Speciality Coffee Association) Coffee Skills Diploma program and have already achieved the Intermediate level in Brewing, Barista Skills, and Sensory Skills.  Each of these modules contribute 10 points towards the required total of 100 required to gain full Diploma status.  This year we are working on the Professional level modules that contribute 25 points each towards the Diploma.

This level of training allows us to better standardise our coffee evaluation and selection process to ensure that every coffee that makes it into the coffee subscription is the best we can find to showcase a particular origin, variety or tasting notes.

We thought we'd take this opportunity to give you an overview of what the SCA diploma course entails, by taking you through our experience of the Brewing Professional course that we have just completed.


The day started early for us on Tuesday as we headed to York station to make our way down to Ealing in West London to attend our first SCA Professional level course (having completed our Brewing, Barista and Sensory Intermediate level exams last year).

As ever, we were greeted by the welcome site of complimentary coffee at Artisan Coffee - which is even better now that they have switched over to their own blend from their own roastery 'Curious Roo'.

After finishing my flat white, the day began with a blind cupping of 6 coffees with our trainer Joe.  This cupping included 2 bright (Ethiopia washed & Kenya), 2 sweet (Brazil & Peru) and 2 heavy bodied (Colombia & Honduras).  This was a challenging start to the day as none of the coffee had the archetypal notes from the region.  In the end, and with a bit of coaching we made it to the final reveal - Crankhouse Kenya washed, Plot Brazil natural (the one we have in the subs this month - it seemed familiar :-)), Plot Peru, Crankhouse Ethiopia washed (Suke Quote), Gentlemen Baristas Honduras washed, and Caravan Colombia natural.  The body coffees had been overdosed to artificially raise body, and the Kenya was amazingly sweet.

After that we moved into the first 5 key parameters for brewing:-

  1. Coffee / Water Ratio
  2. Contact Time
  3. Water Temperature
  4. Turbulence
  5. Correct Grind Size

At this stage, the course is largely practical showing what changes to the above parameters have on extraction percentage and strength of the coffee.  The brew method chosen to provide the greatest control over the parameters was the Aeropress (inverted with paper filter) and the coffee of choice for day 1 was the Curious Roo Ethiopia washed Layo Taraga (incidentally, another coffee that we've had on the Dog & Hat cupping table recently).

Small changes to some of these parameters can lead to large changes in strength and extraction, while large changes to other lead to small changes and the goal of this course is to help you understand which combination of changes you can use to make your desired coffee.

We went through experiments with changes dose size, modifying the brew time, modifying agitation during brew phase, modifying the brew water temperature, changing the bloom parameters and then finished with a V60 pulse pour experiment (used to increase strength by increasing contact time).

So after making nearly two-dozen Aeropresses the day finished, with a quick recap and left us looking forward to Day 2.

Day 2

Having rushed to London on day 1, day 2 started in a far more leisurely fashion as we're now staying with our good friends in London for the duration of the course.  So we arrived nice and early at Artisan Coffee, grabbed a granola pot and a flat white and prepared to tackle the day of learning ahead.

We headed down into the new training suite downstairs at Artisan School and started the day with a triangulation test.  4 sets of 3 coffees were laid out, with one of each set of three being different from the others.  Our job was to identify the odd one out.  There was one sweeter, one more acidic, one oxidised and one with heavier body (10% extra coffee added to brew ratio).  Thankfully we got all 4 odd-ones out correct, though some were definitely tougher than others.

After this we went onto running experiments on the impact of roast profile on extraction by running the same coffee that had been roasted to a light, medium and dark profile through the same recipe on both Aeropress and V60.  We then measured the impact on strength and extraction.  Unsurprisingly, the darker coffee ended up stronger with a higher extraction and the lighter coffee weaker with a lower extraction.

After a break for lunch we were back to it, this time focusing on By-Pass brewing.  Bypass brewing is essentially the process of making a more concentrated coffee and then topping it up with additional water afterwards to hit the desired strength and extraction.  It's useful if you need to brew a bigger batch than you brewing device can natively hold - i.e. you have a 1 litre brewer, but you need to make 1.5 litres of coffee... then you can over extract the original 1 litre brew and then add the additional 0.5 litre of water to hit the desired strength and extraction on your final 1.5 litre brew.

From there we worked on the effect of different filter methods on strength and extraction.  For this we used metal Aeropress filters and a cloth V60 filter to compare against the standard paper filter.  Unsurprisingly, metal Aeropress filters and cloth V60 filters led to a coffee with a heavier body, because more of the oils and insoluble materials from the coffee is allowed through to the final brew.  Another key lesson for us was how much trouble a cloth filter is to clean and store.

Day 3

Day three was water quality and finally, exam day.

We started investigating the difference that water quality has on your brew.  To demonstrate this, we brewed coffee with three different water types - London tap water, Reverse Osmosis (RO) water, and de-ionised water (NOTE - PLEASE DO NOT DRINK DE-IONISED WATER - you must spit out the coffee when tasting it).  The London tap water was extremely hard water, the RO water was in the sweet spot for the SCA water guidelines, and the de-ionised water was as soft as you can get.  The difference in the final brews was massive, and it really highlights that (as your brew is approx 98% water) you really have to pay attention to it.  The soft water was acidic and sour, the hard water was bitter and over extracted, and the RO water was nicely balanced.  So it's clear that to get the most out of your coffee, you really have to have good quality water - we'd recommend an RO machine like the Osmio Zero ( or use bottled water (although the environmental impact of all that plastic doesn’t sit well with us).

Then we went onto the exams which consisted of 2 practical exercises and a written exam.  The first practical exercise was to brew a coffee with a specific strength and extraction and then, retaining the strength, to change the extraction up and down by 4%.  The second exercise was to retain the extraction level but this time to change the strength.  We'll detail more about how these processes work in a future blog post as it is a really useful exercise to help you efficiently dial in your coffee.

We're happy to report that we passed all the exams and are now SCA Brewing Professional certified.  A massive thanks goes to Joe and Artisan Coffee School team for another great experience.

Dave Morgan