... sour or this is too bitter. Then I had no clear idea what to change. Most apps give you a recipe and leave it there. Here is what Cupmark does: Guided brewing. Pick a method (V60, Chemex, AeroPress, French press, moka pot, espresso, or cold brew), follow a recipe, and brew with step-by-step timing. One suggested change. After you taste the cup and write your notes, the app suggests one change for next time, like a finer grind ...