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1lb FB hopper roaster
nickr
Top  #1 Print Post
Posted on 10/16/2023 12:22 PM
Hello,

I decided to start roasting this summer and I am the type to build before buying. I started out thinking I wanted to build a glass chamber electric roaster but trying to stick to a budget, making electric heat was going to cost more than I wanted because of having to go 220v, etc. then I saw a video of a fluid roaster using propane and it all clicked for me. I modeled my roaster like a mini Coffee Crafters Artisan hopper roaster. Using a camp stove inside a stainless pot and a shop vac as the blower. The hopper is an aluminum funnel from a restaurant supply shop. I control airflow with a simple router speed controller and use a 20lb propane regulator to control the heat. I can hit 600f + easily with room to spare in both air speed with 1lb of coffee. All in all I spent about $150 for everything. I later added an active voltage regulator to stop voltage fluctuations that were messing with my loft consistency, but that is optional. FC happens at 395F on this roaster. So far I am still trying to figure profiles and temps to get flavors I want. Eventually I will add chaff collection.




Edited by renatoa on 10/16/2023 12:29 PM
 
wbbh
Top  #2 Print Post
Posted on 10/17/2023 8:20 AM
Nice!

Following
 
progen
Top  #3 Print Post
Posted on 10/18/2023 1:36 AM
Seems like a little low on the bean turnaround rate though.

The small ones available commercially can get away with that because they have narrow chambers and contain only small quantities but for aesthetically consistent roasts, you'll need to at least double that turnaround rate.

Reason I'm saying this is because your hopper diameter to incoming air port diameter ratio looks closer to mine although mine's a 5 lber.
 
nickr
Top  #4 Print Post
Posted on 10/18/2023 9:53 AM
Thanks for the suggestions! The hopper is just over 6" and the inlet is 1.375". To be fair, the video looking down into the chamber is only roasting 1/2 lb test batch. When a full pound is in, its fills out the tapered section. I'll take a new video and see what you think. What would you do to improve? Steeper taper?
nickr attached the following image:
img_2572.jpeg
 
HarryDog
Top  #5 Print Post
Posted on 10/18/2023 7:04 PM
I would bet the 1 pound roast would be better But I would also try a 5 inch wide chamber? Place it in the same funnel and shim it up?

Right now I roast 1 pound in a 3 inch chamber and think it would be better around 4-5 inch for my blower.

I'm very happy with the 1/2 pound roasts but quite pleasantly surprised at my 1 pound roasts. When roasting 1/2 pound batches I think working on my technique is the place to spend my time.

If the goal is even larger batches maybe the 6 inch will be ok.
I used a tapered stainless steel cup (longer gradual slope) for the base hoping the bean will rotate as it falls more then just slide.

Going to be more then one way to get the job done, so cup those roasts and let that taste guide you.
Edited by HarryDog on 10/19/2023 12:18 AM
 
progen
Top  #6 Print Post
Posted on 10/19/2023 3:21 AM

Quote

nickr wrote:

Thanks for the suggestions! The hopper is just over 6" and the inlet is 1.375". To be fair, the video looking down into the chamber is only roasting 1/2 lb test batch. When a full pound is in, its fills out the tapered section. I'll take a new video and see what you think. What would you do to improve? Steeper taper?


i.ibb.co/C6pVMz2/IMG-20220512-164504.jpg

Here are mine. The smaller one on the right is the prototype. 8" diameter. Both have the same height cylinder and use a 2" for hot air.

https://facebook....tid=ZbWKwL

Mk. 2 has a 9" diameter but drastically different taper.

https://facebook....tid=ZbWKwL

Huge difference in performance. Prototype was very easy to get consistent roasts at low blower power but needed a little higher power to break through the beans at start since the bean bed was higher. No deflector needed and bean turnaround rate was very high.

Mk. 2 is more difficult to control so I fabricated a spherical bean deflector although I'm currently experimenting with an enclosed system using a pot lid.
 
progen
Top  #7 Print Post
Posted on 10/19/2023 3:24 AM

Quote

HarryDog wrote:


...

Going to be more then one way to get the job done, so cup those roasts and let that taste guide you.


For sure. And while all of us are copying something that's already in existence, hardware specifications are different so all of us DIYers will have different levels of fun.

😂😂😂😂😂
 
nickr
Top  #8 Print Post
Posted on 10/19/2023 10:10 PM
Hear a video with full load. Showing airflow at 40% to 60%. 60% has too high spout for good rate of rise. I usually roast at 40% and reduce as it dries down to about 25 to 30%.

Edited by renatoa on 10/20/2023 1:29 AM
 
HarryDog
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Posted on 10/24/2023 10:45 AM
How does the roast look and taste? Good to know how it taste as you make changes and determine that the change is for the good or not.

So I think at 40% the bean turn over is a little slow, looking at the 1/2 pound roast it looks a little inconsistent. I think you can improve this by dropping a deflector into the bean spray, a ball or diamond shape to move the beans to the side quicker and the bean mass is as stable as you can get it without trying a different longer/deeper funnel?
 
nickr
Top  #10 Print Post
Posted on 10/26/2023 9:00 AM
as far as looks, washed coffees look pretty uniform while natural and wet hulled tend be mottled.

Tastes are pretty good but not perfect yet. Some roasts have an astringency or drying aspect to them and nearly all my roasts have a faint background "toast" flavor that I do not get in professionally roasted coffee. It's not a bad taste at all but I imagine it is a taste defect to a more established palette. Any ideas as to what are the causes to these flavors? Is it the turnover?
 
renatoa
Top  #11 Print Post
Posted on 10/26/2023 9:40 AM
Except Ethiopian washed, which are a blend of gazillions small farms, each delivering own crop consisting of some 1-10 bags, that are delivered to the processing station.
 
HarryDog
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Posted on 10/26/2023 9:07 PM
So DRUMTC posted a link to this Scott Rao chart for roasting times. I have not tried to verify this.
https://www.bobbo...

Note that I find myself in the middle of those min-max times when I roast.
 
renatoa
Top  #13 Print Post
Posted on 10/27/2023 3:24 AM
20% could be too much for today 4th wave light roasts nordic approach.
That table could be valid for classic roasting style, i.e. medium-dark. And for 10 years ago Grin
Personally I am trying to drop below 16% development time, i.e. 1:30 for 8 min FC, instead 2:00-2:40, as recommended by Rao.
Sour grapes lover Grin
 
jwmelvin
Top  #14 Print Post
Posted on 10/27/2023 6:33 AM

Quote

renatoa wrote:

20% could be too much for today 4th wave light roasts nordic approach.
That table could be valid for classic roasting style, i.e. medium-dark. And for 10 years ago


Yes, Scott recently posted about how his approach has changed: here

“We’ve occasionally neared 20%, but most roasts end up with much lower DTR.”
Edited by jwmelvin on 10/27/2023 6:38 AM
 
renatoa
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Posted on 10/27/2023 7:14 AM
The beginners should be careful to not mix "weight loss" with DTR (development ratio), because they are both percents, and have close range for values.

When we have a short development interval, thus a low DTR, under 15%, i.e. 1:30 minutes development for 10 minutes total roast time, as for a light roast, we expect to have a weight loss under 12%, i.e. 88 grams roast from 100 greens.
A medium roast is somewhere between 15-20% DTR (1:30-2 min dev for 10 min drop), and led to about 14% weight loss (86 grams roast from 100 greens).
A medium rather dark Rao style roast is over 20% DTR and more than 16% loss.

Quote

For reference, Starbucks has proudly stayed near 20% (weight loss)...

Quoted from the article linked above.
20% weight loss is what I call charcoal roast Shock never ventured there, I can't drink so bitter.
 
nickr
Top  #16 Print Post
Posted on 10/27/2023 11:45 AM

Quote

HarryDog wrote:

So DRUMTC posted a link to this Scott Rao chart for roasting times. I have not tried to verify this.
https://www.bobbo...

Note that I find myself in the middle of those min-max times when I roast.


Very helpful article. Still very relevant info for me at least as I like more classic light to medium roasts.
 
HarryDog
Top  #17 Print Post
Posted on 10/27/2023 1:48 PM
You never know how your taste might change as well, I roast lighter then before (Still more Medium) and may try a couple of beans even lighter but I still roast the odd Hot, Fast and Dark for espresso as a palate reset.
 
nickr
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Posted on 10/28/2023 8:50 AM
So you roast fast for espresso? I always read to stretch the roast out?
 
Piotrkurak
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Posted on 10/28/2023 10:03 AM
Espresso doesn't require a dark roast, it is a brewing process that people favor as a dark roast for the added complexities and flavors that concentrates provide. You don get chocolate fourward notes in a light brown roast Ethiopian even as expresso.
 
HarryDog
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Posted on 10/28/2023 12:09 PM

Quote

nickr wrote:

So you roast fast for espresso? I always read to stretch the roast out?


I think they are talking about extending the Development time to reach second crack or into second crack to obtain the roast level they want? Maybe we can use the term traditional Espresso or blends were darker roast levels?

I drink everything I roast as an espresso & Long black about 80%, pour over or french press is occasional when I have time, drip is when I test my roasts that I will be giving to friends so I know how it taste like they brew. Lately I have been using Fill N brew pods for at work and have to say the odd bean has been very good, not all of them.

The first roast I ever did was Hot, Fast and Dark, a mistake in my mind but was a very good cup, I like darker roasted notes at times for blending with coffee I just think needs a little more. This roast style is much like the Allenb and Renatoa two step roasts. I find washed beans can take a bit more heat and pace to the roast. In my roaster the chaff from Naturals often adds a nasty burnt note if I push them, extra chaff, less air flow most likely contribute.

I'm trying to taste as many beans as possible and sometimes my palate gets stuck in this place where everything taste so much the same, those darker roasts help me reset.
 
nickr
Top  #21 Print Post
Posted on 10/28/2023 2:19 PM
I’ve been doing something similar with buying roasted coffees to keep my tastes in perspective. Kinda of like a reset.

For the espresso roasts I’ve been doing, they are dropped at 438f or just before SC. But I have been reducing heat to get there slower. Maybe I shouldn’t be.
 
HarryDog
Top  #22 Print Post
Posted on 10/28/2023 3:18 PM
I think you try it and compare to see what you like, in the end it's your cup.

The type of roaster can dictate much of how you roast, so I think many drum roasters need to drop the temp to compensate at the end of the roast for that stored potential and a FB roaster has to be more careful not to flatten that curve too much or stall the roast.

I have not done many light roasts but today I have 2 beans (Burundi & Ethiopian) I'm going to try a shorter development time and see how it goes.
 
10centNickle
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Posted on 10/29/2023 3:57 AM
This is great, especially for that dirt cheap budget. I'm also looking to do a FB, so if you don't mind me asking, what were the dimensions of the stock pot you used?
 
nickr
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Posted on 10/29/2023 8:52 AM
It’s a 2 qt Bain Marie
https://a.co/d/ds...
If there are any other questions I’m happy to answer
Edited by renatoa on 10/29/2023 10:37 AM
 
nickr
Top  #25 Print Post
Posted on 10/30/2023 10:04 AM

Quote

How does the roast look and taste? Good to know how it taste as you make changes and determine that the change is for the good or not.


Here is a close up of a PNG I roasted last night.
nickr attached the following image:
img_2780.jpeg
Edited by nickr on 10/30/2023 11:10 AM
 
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