Zephyp This is an obvious factor in the flavor and enjoyment. 18-22% EY is typically mentioned, but it could maybe be 17-23%, or wider. I’m not looking for numbers, so the actual EY is irrelevant. The EY where the cup taste best to you could also be different from bean to bean.
Look at it as 95% of coffees in a 4% span (whether 17.5%-21.5%, or 18.5%-22.5%, or whatever (depends on allowances for moisture etc.), but that still allows for tasty coffees that might particularly shine a little outside that range.
I find Brazil, Guatemala, Costa Rica tend to produce less soluble beans, Kenya, Colombia, Rwanda more soluble beans…so yes, from one bean to the next, you’ll get a different good tasting EY. Look at EY data as quantitative, big samples & loose, but tangible trends. A game of averages. It’s useful for going from a malfunction to getting in the ball-park, but not so much for super fine tuning.
Every coffee produces an EY, however good or bad tasting, you can’t make coffee better than it is by tweaking EY, you can just avoid certain brew malfunctions. EYs were historically accompanied by overall liking scores (Quartermaster’s 9 point scale), to gauge preference. An EY by itself is meaningless as it has no context, the same way as if you enjoy an 18g dose of coffee, you won’t like all coffees and changing the dose won’t make every coffee wonderful.
Zephyp Balance, astringency, mouthfeel, silt, thin, dry. Many words are used to describe a brew based on subjective taste. Is it possible to separate and categorize the different factors in a meaningful way that is comprehensible for most, and what possibly caused them?
Balance - to me, not too tangy/sour/tart, not too bitter/dry/dark. It might have acidity/sourness/tartness & bitterness, but overall be not unpleasant, neither dominating the cup to its detriment.
Astringency - 100 barista points for using the current coffee-sphere buzzword! :-) I hate the use of this meaningless, catch-all phrase to describe coffee that ’isn’t quite right’ for some unidentified reason. I’ve seen it used in cuppings and nobody over-extracts cuppings. It’s vague and does not describe a given fault. I wish people would stop using it. In wine speak it relates more to a grainy/powdery/silty quality. To me, in coffee, it specifically describes the drying, smokey, hop like bitterness of over-extraction. This is a distinct & immediately recogniseable type of drying sensation, it is also fairly rare & very easily fixed in 99% of cases by extracting less. Day to day, it’s not a major concern.
Mouthfeel/silt - All coffee has some, people have differing expectations too…you could call it body, or texture. This is seperate to extraction as solids to not contribute to what is dissolved in your cup. If your coffee has a filmy mouthfeel, grainy feel, you might also feel that the acidity is attenuated and the coffee a little flat? Coarsening the grind, or pushing less water through the bed might fix it, without significantly affecting extraction. This, to me, is the day-to-day concerrn - avoiding under-extracted artefacts in the cup (most common issue), whilst minimising unpleasant/overbearing mouthfeel, associated bitter/charred/pithy flavours & squashed acidity.
Zephyp One could get into a very scientific area, naming molecules and what the coffee consist of, but I don’t know if that is helpful to understand the taste and what caused it.
Home users can’t perform any analysis, so I don’t think this helps anyone. Even if it did, corrections are still carried out the same way - grind setting & ratio. Which everyone can do. (Maybe temp too for espresso).
Zephyp If you can hit the extraction with a very coarse grind, can other elements contribute to the brew still tasting poorly?
You’re aiming to hit a preferential flavour, backed up with an objective EY measurement. If you are at an abnormally coarse grind, you might still hit an extraction yield that has been good at a finer setting but, the coffee might be thin in body/the perception of ‘weakness’ and, if you have had to agitate a lot/increase the pouring pulses to get there, you may also notice a silty/powdery aspect too that may detract from enjoyment.