(Charging) Dropping in Hot ???

[Gregr]

Results are in: fast roast C+ shots are just as good as the slower C+ roast. Hard for me to taste a difference between the two- they both have good but not overpowering acidity, great sweetness and long syrupy delicious aftertaste.

[9Sbeans]

Took a photo of this fast roast and if you look closely there are a few places where there are a few dark-ish divots that maybe are just short of turning into little round burnholes.
Edit- replaced the first pic with a crop and circles that mark spots that show what I'm talking about. Dropping the beans right after first crack finishes probably makes this a moot point but good to know that with the fast and furious roasting technique I need to end it very shortly after first crack finishes.

Interesting.  I just finished reading Rob Hoos’ new book, and he describes that the excessively rapid heat application during the drying (yellowing) phase can cause tipping. 

In addition to the initial heat application, I’m wondering bean size, bean density, as well as the initial air flow may also be factors to cause tipping.  It’s good that they had minor effects in the cup.  Did it have the same weight loss % as your regular roast?  How fast would it decay? 

[Gregr]

Unfortunately I didn't weigh any of these roasts so I'm no help there.
The biggest take-away for me, aside from the fact that the whole premise works, is to end the roast soon after first crack is over. 30 seconds after is probably the max if the tipping and scorching happens later in the roast. If Rob Hoos is right then about tipping and scorching happening before or around 300F then more airflow might be the only way to mitigate that defect. Might just be moot though since the roast was very successful as it was. There was no bitterness or roast (burnt) notes.

[9Sbeans]

I did only one run of ultra-fast roast on my current roaster when I first got it and messing around all parameters.  The result was surprisingly good, but I was afraid of the run-away temperature out of control, and hence never repeated it.  Compared to a drummer, a popper or a big fluid bed (like Marshall’s) roaster apply much more hot air flow in the beginning of the roast, and I think it contributes to a more even roast (no scorching, no tipping). 

I may dig into my stash and try an ultra-fast next week.   

[Johnny4lsu]

I'm having a lot of success with Marshalls approach...This is going to be a common way for me to roast from now on if the results continue like this.

[SusanJoM]

This question reminded me to go and find the Sivetz poster on gauging roast level by weight/moisture loss

[9Sbeans]

Thanks Susan, I’ve saved this nice poster in my computer. 
The % weight loss is an indicator of “degree of roast”, and I use it as an important indicator when I want to compare roasting profiles across different roasters. 

In Mark’s [creative nickname] ultra-fast roast, he had temperature segments Dry/Ramp/Development: 2:20/2:20/1:30 and his [drop temp] were [FirstCrackTemp + 25F].  Because we have different equipments, I won’t expect to make an identical replication of his roasting profile.  The variations of BT readouts could be eliminated if we know yellowing/first crack time.  However, we don’t have a common standard to compare the airflow settings.  And this is the reason I want to know the % weight loss.  Generally speaking, the higher the airflow, the greater the %WL.  From my own experiences, I expect to get 12% weight loss if I run a profile in Mark’s settings, and therefore I will need to increase my airflow to emulate his actual roasting conditions.

It sound complicated.  Anyhow, yesterday I couldn’t resist and ran three more batches (my colleagues will enjoy more free coffee next week), and here are the results.
In one of my typical approach, I have initial 30% Fan, and a lower charge temperature.  For the high charge temperature batch, I intentionally set my Fan to 41% at the beginning.  Previously I found out that if I can compress my overall roast time within 9-minutes, I can create a special exciting roast fragrance.  I didn’t want a run-away temperature, and therefore only controlled my overall roast time within this 9-min mark.  The overall Rao’s S-shape, the Dry/Ramp/Development: 3:24/3:22/2:00 ratio and the [1C + 25F drop temp] should put my roast fairly close to Mark’s.  The 13.7% WL was reasonable, because I had longer overall roast time. 

Oh well, it’s just my working hypothesis.   

[SusanJoM]

Unfortunately for the somewhat scientific side of me, the HUKY holds onto too many beans for me to be able to get accurate weights of the end of the roast. 

There are always beans that drop out of the door when I finish the cooling and turn off the fan, not to mention another who-knows-how-many that get vacuumed out of the chute post roast.

[edtbjon]

Unfortunately for the somewhat scientific side of me, the HUKY holds onto too many beans for me to be able to get accurate weights of the end of the roast. 

There are always beans that drop out of the door when I finish the cooling and turn off the fan, not to mention another who-knows-how-many that get vacuumed out of the chute post roast.

That was quite irritating, so I've made a "routine" out of puffing down the exhaust at load, dry, 1C and just after drop. I also twist the tryer quite often. After drop I now get a maximum of maybe 5-7 beans which are still trying to escape it's final grind...

[SusanJoM]

That was quite irritating, so I've made a "routine" out of puffing down the exhaust at load, dry, 1C and just after drop. I also twist the tryer quite often. After drop I now get a maximum of maybe 5-7 beans which are still trying to escape it's final grind...

I'm not quite sure I care enough to do all of that, BUT I have found that if you just leave the trier in upside down no beans will get caught in it...

[edtbjon]

That was quite irritating, so I've made a "routine" out of puffing down the exhaust at load, dry, 1C and just after drop. I also twist the tryer quite often. After drop I now get a maximum of maybe 5-7 beans which are still trying to escape it's final grind...

I'm not quite sure I care enough to do all of that, BUT I have found that if you just leave the trier in upside down no beans will get caught in it...

Well, I'd rather do that (the huff and puff...) than having to sort out half-roasted beans from the finished roast. (Btw, no matter how I place the trier, it always seem to catch some beans...)
On the subject of cought beans, I recon we all agree that this is one of the main PITAs with the Huky. But I still love this machine.

[SusanJoM]

[quote author=edtbjon link=topic=178.msg1684#msg1684
Well, I'd rather do that (the huff and puff...) than having to sort out half-roasted beans from the finished roast. (Btw, no matter how I place the trier, it always seem to catch some beans...)
On the subject of cought beans, I recon we all agree that this is one of the main PITAs with the Huky. But I still love this machine.
[/quote]

I agree, but so far it seems to me that I don't get any "half roasted beans".  The beans that are stuck always stay stuck until after I have dropped the roasted ones into the sieve, so they haven't needed to be sorted....just sucked into the vacuum.   If that changes I will definitely change my ways :-))

[hankua]

[quote author=edtbjon link=topic=178.msg1684#msg1684
Well, I'd rather do that (the huff and puff...) than having to sort out half-roasted beans from the finished roast. (Btw, no matter how I place the trier, it always seem to catch some beans...)
On the subject of cought beans, I recon we all agree that this is one of the main PITAs with the Huky. But I still love this machine.

I agree, but so far it seems to me that I don't get any "half roasted beans".  The beans that are stuck always stay stuck until after I have dropped the roasted ones into the sieve, so they haven't needed to be sorted....just sucked into the vacuum.   If that changes I will definitely change my ways :-))
[/quote]

I'm a "tilter"; backwards after charging and backwards again after drop. Get maybe 4-5 beans each time and very seldom see black charred remnants. I usually roast on low air setting with a max air bump every minute.

One thing to experiment with would be elevating the front of the roaster slightly; maybe a 1 gallon paint stirrer, bottle cap? The idea being if tilting the machine backwards causes stray beans to exit, try a small permanent elevation for the entire roast.

[hankua]

I paid a visit to [creative nickname] recently (Mark) to see his USRC one pounder. He was telling me about the roast and learn
on HB, where they were dropping in hot and ending the roast with very little post crack development time; on a DP Ethiopian.

I think Mark was able to do an 8 minute roast with 1st crack @ 6:30. 

And it worked?

 I believe this theory came from Marshall Hance of Mountain Air Roasting. Marshall has a lot of unusual ideas about roasting, kind of makes you think sometimes. He's using a fluid bed roaster which operates differently than our drum machines as well.

The theory being you can pour any amount of heat while the coffee is in the green stage without scorching. By adding more heat in the beginning the roast can be ended earlier without underdevelopment. More heat can reach the center of the coffee bean.

So lets try this out and I did. Charging at 250c with the heat on 4kpa; that's pretty much wide open gas. At 160c started tapering down the gas, 200c 1st crack with the ROR too high. 1:30 post 1st crack development time 218c drop temp. I ran 5 roasts this way and each time the ROR was not really in control; so maybe the heat needs to be tapered down earlier. I was worried the coffee would be underdeveloped on the first day; second day it was OK. (my normal charge temp is 200c and gas on .5kpa)

Has anyone else tried this out?

This one pound experiment worked and the coffee tasted fine; ran #5 back to back roasts charging at 250c/482f which is insanely high for a  DP Ethiopian. One problem was taming the runaway ROR, in the beginning I left the heat on high until 160c/320f vs 150c/302f.

Let's take a look at the profile: Charge 1lb at 482f/4kpa, at 302f/3kpa, 320f/2kpa, 338f/1kpa, 356f/.75kpa (air to 50%), 374f (change dependent on profile development), 392f 1st crack begins. If you hit 1st crack hard the roast can be dropped after 1:30 has elapsed. Of course this would be a drip roast, the segment starting at 356f is where one can adjust the ROR to finish at a target temp/time/personal preference.

There's a lot of new ideas being discussed regarding coffee roasting, Rob Hoos's little book gets scientific about the chemical reactions. One thing for sure, the idea of development starting at 1C is changing. How about development starts at 150c/302f and lasts until drop?

[Gregr]

After a very successful first round with the fast roast approach (still waiting for a catchy name) I'm going to try it again today with Kenya Kirinyagi peaberry. I'm a little worried though that this might be a bad bean to roast quickly because the notes say it's a very bright coffee, but very good as SO espresso. Anybody have any input I'd love to hear it. I guess worse comes to worst I can just freeze it and use it for the rare occasions when I want coffee and not espresso.