Simple DIY mod for shop drum roasters (500g-3kg)

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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baldheadracing
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#1: Post by baldheadracing »

This Japanese home roaster put a hole in the exhaust manifold, attached a small hose, and uses the hose to smell the roast as well as hear it. It seems like a neat idea to me and I've "put it on the list."

(The issue with using the trier for smelling the roast is if you use a high(er)-airflow roasting style then you can end up pulling a lot of air through the trier if you work the trier a lot. This isn't an issue in a bigger roaster, but in shop roasters using the trier a lot can give a different roast compared to a roast where one didn't use the trier. (By high-airflow style, I mean where you set the airflow system to one fan speed and/or air restrictor setting and don't change the settings throughout during the roast.))

This is the best still shot of the hole location in the exhaust manifold that I could pull from the video. The location might be a bit tricky to identify as I'd guess that you'd want it in a position that isn't sucking air in(?)


Smelling:



Listening for cracks:



Source video in Japanese (turn on English subtitles):
FYI:
- the roasting machine appears to be a Fuji-Royal 3kg https://fuji-royal.jp/en/products/roaster/r103/ and the grinder looks like the Fuji-Royal R-750
- the big gas lever is also a mod. The stock lever looks like the usual ball valve lever.
- the male speaking near the beginning of the video - when they're cupping at a café - is the Coffee Sakura guy ( https://shop.coffeesakura.co.jp is where folks used to buy Fuji-Royal grinders before they were widely available on eBay, Amazon, etc.).
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

Milligan
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#2: Post by Milligan »

I installed an "aroma valve" on my Cormorant. I don't use the trier because it has a major effect on the roast when I pull it. So I put it on the positive pressure side of the fan so air blows out when I pop the cap off the tube. Works fairly well. I can post pics later.

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hankua
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#3: Post by hankua »

Looks like he has the tube located on the vacuum side, in the plenum. And maybe closing off the air valve when using the tube, then resetting air afterwards.

Capuchin Monk
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#4: Post by Capuchin Monk »

baldheadracing wrote:This Japanese home roaster put a hole in the exhaust manifold, attached a small hose, and uses the hose to smell the roast as well as hear it. It seems like a neat idea to me and I've "put it on the list."

(The issue with using the trier for smelling the roast is if you use a high(er)-airflow roasting style then you can end up pulling a lot of air through the trier if you work the trier a lot. This isn't an issue in a bigger roaster, but in shop roasters using the trier a lot can give a different roast compared to a roast where one didn't use the trier. (By high-airflow style, I mean where you set the airflow system to one fan speed and/or air restrictor setting and don't change the settings throughout during the roast.))
As for hearing the crack, I thought it's the bigger roasters with thicker wall construction making it difficult to hear. In such case, I brought up mechanic's stethoscope.

Depending on where you put the smelloscope opening, you may either smell the beans, smoke or bean smell mixed with smoke.

rmongiovi
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#5: Post by rmongiovi »

There was a post a while back - Diacetyl in Coffee Roasting and Grinding - that talked about harmful chemicals given off when roasting (and grinding) coffee. Out of an abundance of caution I think I'd be looking to minimize my exposure rather than trying to sniff my roast.