Volume of First Crack

Hi Folks!

I have not posted in a while. Work getting in the way of Life, and all that.

I have a new theory! (which means, of course, it may be way wrong)

After I switched to the CoffeeMind recipe (230 preheat, P8 to 150 then P6 to 190, then P5 to drop) I noticed I had a very hard time hearing first crack.

I figured it was one of two things - my hearing started getting worse (not impossible for a 65 year old who did like rock and roll in his youth) or the beans were just not very “cracky”

But I didn’t like the sweet smooth flavor that a long dev time gives you, so I juiced up the roast temps. Now it is 235 PH, P8 to 155, P6 to 195, P5 to drop.

Low and behold, I can hear first crack again. (and I got a more acid, more bitter roast)

Am I crazy? Has anyone else seen this? I think I can explain it by saying the water gets hotter sooner, and bursts through the cell walls, but heck. I am no organic chemist.

You can see my recipes in my profile (CoffeeMind Standard, and CoffeeMind Running Hot) and there are a number of roasts with each.

Hope everyone is well!



I looked at two of your profiles, one running hot and one standard. They were different beans and you didn’t mark end of first crack, but my guess is that your running hot is producing a more aggressive first crack where more beans are cracking at once, amplifying the sound. I find that I can hear first and second crack better if I wear Bose noise cancelling headphones. They tend to block white noise, but let small pops and cracks through, so they cracks are more audible over the consistent sound of the drum and fans (I have a second fan pointed at the PCB).


I’ve used the noise cancelling headphones as well. They really do work.

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Brilliant! I’ve been struggling to hear FC and just figured my hearing loss was the reason - it probably is but I have Bose noise cancelling headphones and I am definitely going to give those a try before looking at stethoscopes or other “focussed amplification” systems. Thank you.

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From my experience different beans behave differently in terms of FC and SC even when I use the “same” roast plan for the two different beans. Some beans crack louder than others for sure - without any “hearing aid devices” on my part.

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