The effect of decaffeination on coffee's roasting and grinding performance
Mark Al-Shemmeri · Independent research write-up · 2023 · medium.com
The only controlled look at how decaffeinated green behaves differently in the roaster and the grinder. Its finding runs directly against the standard shop-floor advice, which is why it matters.
How much weight this carries
Contested. This source disagrees with the widely repeated position, and neither side has settled it.
What it says
- Decaffeinated coffee grinds finer at the same grinder setting — Producing more fines than the equivalent caffeinated coffee.
- More fines pushes toward over-extraction, not under-extraction
What it does not say
- It does not conclude that you should grind decaf coarser. It reports a physical difference; the brewing recommendation is an inference, and a contested one.
- It is not a cupping study. It says nothing about which grind setting tastes better.
Recorded because the errors in this subject all point one way: toward claims more confident and more flattering to decaf than the evidence supports.
Limitations
A single independent write-up rather than a peer-reviewed and replicated result. Cited here because it is the only controlled evidence available, and because the alternative — repeating shop-floor lore — is worse.
The honest position on decaf grind size is that it is unresolved. Shop-floor advice says finer, on an under-extraction theory. This is the only controlled evidence, and it points the other way. Dial in by taste.
Cited on
- How to brew decaf Guide
Related sources
- Mountain Water Process Industry source · Descamex
- Swiss Water — decaffeination process and caffeine content Industry source · Swiss Water Decaffeinated Coffee Inc.
- Sugarcane EA decaffeination process diagram Industry source · Cafe Imports