I attended Ben Kaminsky's Advanced Brewing Techniques Workshop at The Coffee Collective. I thought I would like to share my impressions from the workshop as I digest it. In this edition I would like to focus on extraction and brewing devices for what is commonly called filter coffee.
I have for some time had an interest in extraction. What are the mechanics behind it and how can you adjust parameters to achieve the extraction you desire?
Ben started with presenting a lot of information I felt quite familiar with, but he soon included new knowledge and experience. I guess my take away from the workshop is new ways of thinking about what I already knew along with, of course, a lot of new stuff too.
He emphasized measuring extraction before comparing taste of different brews. So he was constantly measuring every brew he made and provided the numbers.
As I was tasting his 23-24% extractions og TCCs Kieni I couldn't help thinking, that it didn't quite taste as I have been used to. It wasn't as crisp and juicy as I like it.
At TCC I often prefer their brew of Kieni on V60 or Kalita Wave. They often try to talk me into trying the Aeropress brew, stating that this brew method gives a more rounded cup. I think it's more sweet and I don't really like it. Bens brews were better but were leaning toward the AP brews I have tried.
So in order to understand his preference I asked from which filter brew method he prefers the taste. He looked puzzeled as if my question didn't make sense. I then asked specifically about V60 vs. AP. I further explained my perception of the taste difference. He then asked if I had measured the brews. Of course, I don't get to do that at TCC. He then said that I couldn't compare them. Actually he said something to the effect that if you brew a V60 and an AP with the same extraction and TDS, then they should taste the same.
He didn't get further into this, but my interpretation of this is that he basically states that if a V60 and AP brew of the same coffee doesn't taste the same, then either one or both of them are under extracted or over extracted or the strength is different.
Now this is very interesting in the perspective of home baristas and coffe shops claiming, that different brew methods objectively give different taste experiences. In Berlin I have even experienced a coffee shop insisting on brewing different coffees on only the one brewing device that they believe provides the best taste experince for that coffee.
If I understand Ben Kaminsky correct, he basically believes that this is BS and they should measure the brew and not care too much about the method, as long as they can get the desired numbers. Now, this is interesting in the perspective of the above, but also i relation to the different attributes of typically using a diffent grind size and brew time for the two devices. Not to mention whether to use paper or metal filter, which people (including myself) often attribute to giving different taste experiences.
Let's take a simple example for a moment. We use 60 gr. coffee and target for a 20% extraction and 1,33% TDS. According to ExtractMoJo we should use 964 gr. water to get 857 gr. brew.
With V60 there's only so much we can do to achieve this, since the water flow is determined mostly by coffee weight and grind size. If we grind finer we will brew longer and extract more. If we grind coarser we will brew shorter and extract less. So there's a sweet spot that will bring us close to the target (if we don't stir, of course).
With AP we can go upside-down and brew with full immersion and get more agitation as we stir, turn and plunge (actually with immersion the numbers should be 844 gr. water to get 737 gr. brew, but I don't know if ExtractMoJo considers AP upside-down as immersion). We can grind finer and brew shorter og grind coarser and brew longer. What's unclear to me is, if Ben states that these different ways of achieving the same TDS and extraction will taste identical. Am I even correct to assume these properties of brewing with AP?
Also, since the Brewing Control Chart recommends extractions to be in the range 18-22% and Ben was brewing 23-24% extractions, I asked him if he thinks that the chart should be changed. His answer was no, since the EK-43 grinder is special and most brewed coffee will fall fine into the chart. But according to the chart extractions over 22% should be bitter. If they're not with Bens 23-24% extractions, then is the chart based on a particular grind particle size distribution? Since the chart was made many years ago, does it really only count for darker roasts?
I guess the workshop leaves me with new inputs, but also with a lot of questions. I know many people are interested in using an espresso machine for coffee shots, but I think that this filter coffee topic also deserves some thoughts. I think I will start experimenting with different parameters for AP brewing to see, if I can get the same number using different grind sizes and brew times.