Uploaded November 2025 | Updated September 2026, 1 week ago

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Note: All stones used in the testing came from the destoning of raw coffee - so are good indicators of the kinds of stones you might find in a bag of roasted coffee.

What happens if a small stone makes its way into your bag of coffee and your grinder? An irreversible calamity or an imperceptible event?

My 1 Cup V60 technique: youtu.be/1oB1oDrDkHM
Our new pour over setup still life print from TensHundredsThousands: geni.us/THT-Still-Life

0:00 Intro
1:38 How do roasters filter stones out?
3:52 Our test parameters
4:46 Testing pt. 1
10:39 Burr inspection (with a microscope!) part 1
11:12 Testing pt. 2
12:02 Burr inspection (with a microscope!) part 2
12:31 Testing pt. 3
13:09 Particle size analyser results
16:41 What to consider if it happens to you
18:30 Testing pt. 4
21:49 Taste test

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How to Make The Best Coffee At Home*: geni.us/howtomakethebestcoffee
The World Atlas of Coffee*: geni.us/worldatlasofcoffee
The World Atlas of Coffee Audiobook*: bit.ly/worldatlasofcoffeeaudio
The Best of Jimseven*: geni.us/bestofjimseven

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My new glasses (Sept 2024 onwards): bit.ly/thenewglasses
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