Hey,
I ruined a cup of coffee on purpose this week. That was the whole assignment.
I gave myself a challenge. Push the extraction way up, into the 21 to 25 percent range, a TDS reading between 2.4 and 2.8, and still keep it drinkable. No bitterness, no hollowness. For reference, most of my pour overs live around 1.2 to 1.5. So this was me deliberately driving into territory I normally steer away from, just to see what happens. Because I learn more from my failures than my good cups.
I took a very light Guatemalan, ground it espresso fine, and used my Hario Switch so I could hold the water on the grounds and really soak them. I even reached for the dark roast water profile instead of the light one, trying to pull some balance and sweetness out of a coffee that had no business being that strong.
I hit the number. Almost 24 percent extraction, a TDS just under 3. On paper, challenge complete. In the cup? It was potent. Strong as anything, with a bitterness sitting on the aftertaste that got in the way of everything else.
And that's actually the lesson. When you over extract, the real problem is the bitterness. It climbs on top and buries the very things you're trying to taste. The acidity, the sweetness, the character of the coffee, all of it gets harder to read. You can't understand a cup you can't taste past.
You do not need to do this. I'm not telling you to brew your morning coffee to a 2.9 TDS. If your cup is landing where you like it, leave it there. This isn't a new recipe, it's a stress test.
But here's why it's worth it. You can't really know where the middle is until you've been to the edge. Deliberately going too far, too strong, taught me exactly what over extraction feels like on my tongue, so I can catch it the second it starts creeping into a normal brew. The failure sharpened the target.
That's why I keep doing these. Watch the whole failure challenge here. Then hit reply and tell me what I should deliberately mess up next. These are the ones I have the most fun with.
Oaks, the Coffee Guy
"Just keep reading. I've got you."
Here's to the journey. Yours and mine.