• Setup: ChemEx, Baratza Encore, and reusable coffee filter
• Grind size on Baratza: 30
• Coffee Dose: 35 G
• Water Volume: 585 G- ish
• Water Temp: 205 Fahrenheit

I keep reading that bitterness is because I'm grinding too fine. But 30 is far higher than the standard chemex size. Should I go even higher to 35? Or could it be another reason altogether?

What's the coffee your brewing and how many days have past since it was roasted? How long does it take to pour the water through the coffee?

I would first try grinding coarser, not worrying about the absolute number on the grinder, and if that doesn't work drop the temperature of the brew water.

How dark is the coffee you are using?

Try paper filters. Reusables tend to let fines and oils through that can give a bittering taste and lack the clarity of paper.

Hedrick has a good youtube on hacking Chemex. It involves modifying the Chemex paper filters and putting. . .I don't know what he used, but I use a silicone cake pan liner on the spout. I'm not saying any of this will cure bitterness--the others have you on the right track--but I think it does improve the overall cup quality.

I am wondering if you actually grinding too coarse and are tasting under extraction. I find it can be a bit hard sometime to distinguish the two tastes.

How is your time when brewing?

Getting pour over right is very hard, in my humble opinion. One of the revelations for me, after having followed YouTube advice too much, was lowering the brew temperature quite dramatically. I now brew with around 90-93 degrees celsius. Only upping if the coffee tastes like it would get a boost in sweetness with higher temperatures.

Other things to watch out for are too much agitation and too many pours. I would wager the Encore is somewhat similar to Kinu in that it does generate a good amount of fines, which you should be careful to not extract too much.

I completely agree. I'm not sure how people are drinking pour over brewed at 100C. I typically use 93 and only go up with much lighter roasts or down with some mediums.