Astringency and Sourness

[TCR]

Hi guys!

So I'm experiencing a little astringency and sourness with a Colombian Honey process coffee we are currently roasting and offering our customers. I'm a little confused as I know astringency is usually associated with over extraction/darker roasting but sourness under extraction/lighter roasting. The bean looks fully developed when cracked open, so I don't think its underdeveloped. Brewing with a Kalita wave at 2:30min with 21g/350ml ratio. Roast is around 11:30, with FC at 10:00. Confused as to why we are experiencing both problems at the same time! A dryness at the end but also a sour sharpness. And its not a good 'acidic' sharp, its just sour.

Any thoughts? Could it be the green/bad processing etc? Or our roasting?

Thanks guys!

 

[ensoluna]

Personally speaking, I think it is due to Honey process done wrong from the farm side because it seems like your guys know what you are doing with roasting and extracting...etc.
Please have green coffee buyer take a look at the green beans (I am assuming that it is 2015/2016 harvest, fresh coffee).

Below are the photos from one of Antigua Guatemala farm that we represents, but NEVER SOLD THEIR COFFEE to our customers due to over fermentation problems that they just can not get over... This farm specialize in Black / Red / Yellow honey process and Natural process, but it is not clean! Attached are some close-up honey processing bean photos, so you can tell they are not clean...

however, it could be...could be water temp or even grind levels. so, if you want to do some experiment, you can grind in different levels and try out with different water temp (210 C / 195C / 180C) to make it sure that it is not roasting or extracting problem.

good luck.

 

[Musicphan]

You mention FC at 10 min.. is that the start or stop? When does your FC stoP?

 

[sae]

I was going to mention it sounds like a green bean issue as well after you answered all the obvious questions (time to FC, degree of roast inside, etc)

 

[TCR]

Personally speaking, I think it is due to Honey process done wrong from the farm side because it seems like your guys know what you are doing with roasting and extracting...

Hi! Thanks for the response! Sorry for the late reply. I was worried for a bit that it might be overfermentation, however the astringency and sourness isn't a consistent problem with the sacks. I tried adjusting the grind a tad and extending the brew time which countered some of the sourness but in turn gave heavy body. I'm just going to keep playing around. We also realised when we were serving the coffee via pour over we had a big open door which was drafting in a lot of cold air. I think this way playing with the water temp and effecting extraction, hence sour.

 

[TCR]

You mention FC at 10 min.. is that the start or stop? When does your FC stoP?

Sorry, start of FC at 10 min

 

[JohnD18]

Hi guys!

So I'm experiencing a little astringency and sourness with a Colombian Honey process coffee we are currently roasting and offering our customers. I'm a little confused as I know astringency is usually associated with over extraction/darker roasting but sourness under extraction/lighter roasting. The bean looks fully developed when cracked open, so I don't think its underdeveloped. Brewing with a Kalita wave at 2:30min with 21g/350ml ratio. Roast is around 11:30, with FC at 10:00. Confused as to why we are experiencing both problems at the same time! A dryness at the end but also a sour sharpness. And its not a good 'acidic' sharp, its just sour.

Any thoughts? Could it be the green/bad processing etc? Or our roasting?

Thanks guys!

Your development time is currently at ~ 13% which is very short, and will lead to underdeveloped flavors in the coffee. Try keeping the development time between 20-25%. So, if you're hitting FC at 10:00, you're not going to want to drop those beans until about 12:50 (not necessarily darker though. Find the ROR that will get you to your current drop temp at that time). That will give you 22% which is where I usually begin developing the profile.

Sometimes honey processing can give a sour/fermented tasting note, but it can be subtle and sweet if roasted right. Try extending your dev time to over 20% and see how it goes.