I used to roast on a Gene Cafe, then recently the North Coffee 2kg TJ-072.

In my first batch, I loaded about 800g of my usual espresso beans. Here's what happened:

2.5 mins - yellowing
6.5 mins - 1st crack
8 mins - 2nd crack

Back in the Gene, I never reached 2C but roasted to about 12 minutes total. I've decomissioned the Gene down in my basement, so I'm to lazy to compare. For sure, though, the quick roast was a bitier espresso and had a welcome acidity both as espresso and americano, as well as in a cappuccino. Bitier as in more fragrance and effect through the inner nostrils.

In my 2nd and 3rd batch, I loaded 500g each of my pourover-brew blend, and again achieved a quick roast time. Sine I roast "medium" and "dark" roasts of the same blend for my market, I made sure i didn't overshoot 1C for "medium", and touched lightly on 2C for "dark", nothing going beyond 8 minutes. Tasting them each through the V02, I once again found better results. The medium was nicely bright, fruitier and more interesting than when I was doing it on the Gene. The dark was chunkier of course, but it still retained a menthol kind of effect.

A good reference to my finding would be an article on Sweet Maria's "Drums Roasts vs Air roasts" where the writer described air roasts gaining better acidity but lesser body. Although I AM using a drum roaster, the quick roasting is probably akin to air roasting.

I also wonder what consensus there is on the 12-15 minute roast times.

Thoughts are most welcome.


Pic 1. 8 minute espresso roast (used to be 12)


Pic 2. Right jar is the medim roast, left jar is the dark roast

P.S. When I scale up on my 2kg machine, I would need stronger propane pressure if I would want to preserve my quick-roast times. RIght now, large capacity is doing well for low-weight (500g - 800g) roasts.

I went from a GeneCafe to a Huky500. (I was contemplating a TJ-067, but as I live in an apartment and hauling a 220# roaster up to the third floor isn't possible. ) I take it you've already noticed that you really cannot compare the Gene with the North. It was when I started roasting on the Huky I realized how much I had to learn about roasting.
While I can roast say 250g (half the capacity of the Huky) of greens in under 8 minutes, I loose out on a lot of the other aspects of a good nice roast profile.
IMO, the whole idea with roasting speciality coffee (same call it artisan roasting) is to be really careful with the roasting profile and to try the very best to bring out the subtle flavours out of the greens. That is difficult if you rush through the roast. I'm not saying you have to adapt to e.g. Scott Rao's style of roasting, but that is at least a very good excersize when learning to control the roaster and the roast.

I am wondering if you actually hit second crack. It could be difficult to differentiate between 1st crack and 2nd crack as you were switching to a new roaster and progressing so quickly. The picture doesn't really look like 2nd crack to me mainly because of how light the chaff in the crack looks. I could be barking up the wrong tree there so please don't get insulted if you can easily tell the difference between 1st and 2nd crack. Another thought is that your roast might taste brighter than you would think if you developed the outside of the bean more quickly than the inside. My experience is that higher airflow is needed for a quick roast in order to keep the inside of the bean caught up with the outside. I would love to hear another opinion on that...

If you like the taste, yay. If you don't, nay.

Fwiw, I use an air roaster and this year sped several of my roast profiles from ~10mins to 8mins, then slowed them back up to 9mins. With faster roasts I found more acidity, but less complexity. A given coffee would be described as "clear, bright cherry juice, floral, tea-like." I didn't love them "Japanese ice brewed" (poured-over ice). With a slightly longer roast, the same coffee is being described as "cherry preserves, orange zest, syrupy, powdered sugar." In my experience too-fast seems to muddy flavors into one discernible note, and slower roasting allows the taster a greater chance of picking out different notes.

I used to roast on SR fluid beds, but now roast mostly on a Quest M3 drum. A few observations. Of course, it is nearly impossible to discern colour properly on a confuser , but to me your big picture looks really light...nearly a cinnamon (something I rarely roast to). Your medium also looks rather light and your dark maybe only a medium. To me, to be a 'dark' it should be into 2C and should begin to display at least some surface sheen. So, as another commenter said, I wonder if you're getting to 2C at all. Terminology is not the same for all of us, and I generally roast according to the following terms: City (end 1C) > F City (quiescent period) > F City + (barely 2C) > Vienna (into 2C) > French (rapid 2C)). So, sorry, but I'm not sure what you mean by medium and dark...maybe we're not talking the same 'language'.

I also wonder what consensus there is on the 12-15 minute roast times

That sounds about right to me overall, but a lot depends on your target temperatures/times for drying, ramping and finishing. On my SRs and my M3 this is about the time frame I shoot for when I do a FC+. I try to get to dry (~150 C) in about 3-4 minutes), 1Cs about 5-7 minutes later, and 2Cs (where I usually dump) in another 3-4 minutes. Of course, what I do varies with the sort of coffee and for what what I'm planning to use it.

It depends on the coffee, but for the most part experiences here are similar to Kian's. Faster gives you more "zing," slower tends to be muted but also more complex, especially if you spend the extra time in the Maillard zone (300F through early first-cracks). I've had a few very good lightning fast roasts, and some good slower ones, but mostly my favorites lie in the 8-10 minute range.

I had 1 coffee last year, the Kenya Kiangoi, that really shone in a fast roast. First crack around 5:30. Most coffees I roast are longer then that.

wearashirt wrote:I used to roast on a Gene Cafe, then recently the North Coffee 2kg TJ-072.

In my first batch, I loaded about 800g of my usual espresso beans. Here's what happened:

2.5 mins - yellowing
6.5 mins - 1st crack
8 mins - 2nd crack

Back in the Gene, I never reached 2C but roasted to about 12 minutes total. I've decomissioned the Gene down in my basement, so I'm to lazy to compare. For sure, though, the quick roast was a bitier espresso and had a welcome acidity both as espresso and americano, as well as in a cappuccino. Bitier as in more fragrance and effect through the inner nostrils.

In my 2nd and 3rd batch, I loaded 500g each of my pourover-brew blend, and again achieved a quick roast time. Sine I roast "medium" and "dark" roasts of the same blend for my market, I made sure i didn't overshoot 1C for "medium", and touched lightly on 2C for "dark", nothing going beyond 8 minutes. Tasting them each through the V02, I once again found better results. The medium was nicely bright, fruitier and more interesting than when I was doing it on the Gene. The dark was chunkier of course, but it still retained a menthol kind of effect.

A good reference to my finding would be an article on Sweet Maria's "Drums Roasts vs Air roasts" where the writer described air roasts gaining better acidity but lesser body. Although I AM using a drum roaster, the quick roasting is probably akin to air roasting.

I also wonder what consensus there is on the 12-15 minute roast times.

Thoughts are most welcome.

<image>
Pic 2. Right jar is the medim roast, left jar is the dark roast

P.S. When I scale up on my 2kg machine, I would need stronger propane pressure if I would want to preserve my quick-roast times. RIght now, large capacity is doing well for low-weight (500g - 800g) roasts.

Hopefully it isn't taboo around here to revive 30 day old threads, but I find this one particularly interesting and would love for the dialogue to continue. Are you still getting fast finish times? Have you experimented with extending the times? Comments on the previous posters 2nd crack hypothesis?

My personal preference in taste is 11-14 minutes reaching 400-425 degrees F at finish. this results in a city through city + roast for me with a SF-1 drum roaster.

I've gotten away from darker roasts as I've stepped away from my espresso machine for a little while in favor of pour over and other brewing methods