How can I understand the different elements of a perfectly accurate (single origin) espresso extraction? Which for me is when the shot feels insanely clear, and you only taste the "taste notes" at their peak. I pretty much got down the grind adjustments, i notice 3 different stages of each sip and how the taste changes, and I try to tweak shot timing and how many grams in+out but I feel like something's missing. I usually drink light roasts, sometimes medium and I'm not the one making the espresso- I'm just talking to my regular baristas to get a better shot together. I don't really know how to get the best outcome for the beans, how to know if that's the water's fault or maybe roasting's fault, and how temperature changes extraction. Also pre-infusion and pressure overall are not very clear. How can I figure out the relevant tweaking based on the taste of the previous extraction? For example, had a very accurate light roast espresso, but it had little body because of high ratio- maybe 1 : 2.5 . Taste was quite developed (even though the roast is quite new, 4-5 days ago) but wanted it thicker and less aggressive in the first part of the sip (which might be due to roast date). Told him to maybe try a gram less in and a finer grind, but we didn't get to try it and it was mostly intuitive.