Difficult to hear first crack compared to my old roaster

I’ve just finished seasoning my R1 and have done my first roast:

After looking more carefully, I may have stopped the roast slightly early. I heard one or two cracks for sure and marked first crack, but I am not sure if I really heard it “roll”. I know this can be very different for different coffees. Some barely make any noise. Up until now all my roasts have been on an old Behmor 1600, which is a pretty quiet roaster, I think.

I’m also wondering if perhaps it was subdued because I wasn’t using enough heat. The ROR seems to have gone very flat for a long time. I’m not used to having this instrumentation. I’m more used to roasting totally by sight and sound.

I’d really appreciate any comments or feedback on this.

I also went from Behmor to Bullet, and agree, it’s a bit harder to make out, but it does come with practice.

I also agree that if your RoR goes flat, you’ll have a hard time making it through 1st crack. I try to keep mine around 9-10°C / minute until the last 15° of roast, where I pull it back to 5°C/minute. If it goes flat, crack can stop even if it’s not done.

I agree that it’s just plain hard to hear the crack with the Bullet. The noise of the beans crashing in the drum masks the sound of the crack. I find SC even harder than FC.

  • one user created a stethoscope from a mechanics stethoscope by replacing the thin probe with a tube to fit the trier port. (Do a search… he had photos with his post.)
  • a couple days ago another user mentioned using a kazoo as a makeshift stethoscope; also fitted to the trier port. (Again, do a search for the photo of what he did.)
  • it helps me to just tilt the rubber plug of the bean chute for a moment (though it has to be mostly left in place as it can probably affect air flow thru the drum if left off).
  • getting your ear down to the level of the opening at the bottom of the face plate (where the chaff bleeds out during the roast) might help. Frankly I’m not flexible enough, but maybe it will work for you.

I gave up trying to catch the start of crack with the first few pops… my times were all over the place. I wait till it gets going a bit before recording the time. Conveniently you’ll see some reaction with RoR as FC starts. That and keeping track of the temp (either Bean or IBTS) for confirmation that you’re hearing what you think you’re hearing will (hopefully!) get you there. Thankfully the cracks are pretty consistent vs. temp.


Thanks for all the input. I tried the coffee this morning and it was almost drinkable, but not. It did have an incredibly bright first impression that I’ve never gotten out of a Behmor roast. Usually when I under-roast coffee in the Behmor it just comes out tasting like wet grass.

Today, I did another Guatemala roast, although not exactly the same bean:

This time I approached first crack with a lot more momentum and I was able to hear it clearly. I now think that the issue I was having yesterday had more to do with heat than hearing. I still may have backed off too much after entering first crack? It is hard to tell. I’m pretty sure this coffee will be drinkable though.

During my first few roasts, I couldn’t hear a 1st crack at all. However, with more and more roasts, it seemed to become clearer and clearer. Now, it’s like second nature. It also seems to help (me, at least) to put my ear lower down, even below the sight window. You’ll get it…

I’ve not seen or heard the bullet in person during a roast, but not hearing 1C or 2C seems to be a thing. On youtube videos the beans spinning does seem noisy although you can’t tell anything from a recording. If SM receipt date is correct I’m getting close to having to pull the trigger on one or not, and in my case I roast decaf half the time. I do a full run of each when I roast and I’d be looking at (2) 900gm batches of decaf every week.

I saw elsewhere that decafs can be difficult to hear, anyone familiar with this? With the 1600 for me it’s a balance of time and sound to roast, I depend on 1C with time.

I recently went thru a wrestling match trying to recover how to roast decaf. It had been years. I struggled picking out even FC till I replaced the beans… they were ancient by years! The fresh beans seemed easier to ear and my guess is it had to do with the freshness and minimal age.

You don’t have a roaster to use to confirm this, so if you do end up buying a Bullet, try to recall that someone mentioned that getting your ear near the bean chute and then tipping the silicone plug to the side so that sound reflects toward your ear will help a lot regardless what beans you’re roasting.

Also, I watch the temperature closely near FC regardless what I’m roasting. It’s much easier to hear the crack if you are confirming the sound rather than searching for the sound.


I have a 1600 im using at the moment and i can always usually hear 1c and 2c with decaf. Time doesnt mean as much as sound going between different coffees. I almost totally rely on sound when i expect it but on the 1600 external temps influence things more.

I have a length of 1/2" silicone tubing that fits snugly in the trier hole and putting the other end to my ear allows me to hear clearly what’s going on inside. Even better than a stethoscope.