Would appreciate feedback on this topic!
I've been pulling 10+ dialed in shots yesterday @ stock 13 bar, and all of them had pleasantly obvious blueberry aroma & flavor in the cup, even though its harsh when drinking straight.

After lowering to 7 bar, harshness is almost 100% tamed, but all blueberry flavor is gone even though it tasted sweet. I'm also surprised that 22 second shot can be slightly burnt/bitter @ 7 bar.

Any recommendation on how to achieve "not harsh" flavor while getting maximum fruits/flavors?
Would you recommend lowering yield (from 1:2.5 -> 1:2)?
Maybe even lowering temp to 200 to bring a bit of acidity back?

I'm also thinking of bringing pressure up to 9 bar, but logic is telling me its going to make it slightly harsher?

Machine: Rocket Appartamento HX

Temp: 205 F

Prep: WDT & Calibrated 25 lbs tamper

Beans: Natural Ethiopian, (very) Light Roasted, 8 days old today

Pressure: Stock @ 13 bar = strong fruit but harsh. 7 bar = bland but "sweet", no blueberry at all.

Dose/yield: 17g in -> 40g out in ~22 sec on both pressure (slightly different grind)

Thanks a lot for taking the time!

7 bar?
6 bar police wont be happy.

13 is too high. my experience is anything above 10.5 will give harsh/burnt/bitter aftertaste. between 8.5~9.5 will probably be about limit i think. i might be wrong.

i noticed lower bar tends to emphasis more brighter notes and sharper acids, and higher bar to emphasis lower darker tones.
if consider blueberry to be the heavier darker type notes, you might want to try 8.5~9bar instead.

if you didnt loose sweetness after ur adjustment, your ratio might already be correct. maybe try 2.3 to avoid last bits of harshness. temp tends to affect sweetness especially if too low but too high will also gives burnt taste.

ymmv. good luck.