Hi all-
I am trying to dial in good roast profiles to accentuate sweetness in light roasts. I am able to achieve the tasting notes consistently, but cannot seem to escape tartness even in “fruit heavy” descriptions. Perhaps I need more development time, I realize 14.91% (below) is not optimal? But, if I go past 1/1.25 minutes after 1st crack, I tend to lose too much weight percentage. I am shooting for 12ish% loss range. Am I putting too much stock in weight loss? Should I let the roasts sit for over a week to try etc? … See attached Rwanda light roast curve. Thanks for any help!
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For what it’s worth, I think 1:30 development time might be too short if you think it’s too acidic. For light roasts, I used to fuss over a low weight loss but it’s less important to me now.
Thanks for your advice! A few more related questions:
- If weight loss is less important, then is the color of the beans also not so important for attaining the subtle flavors of a light roast?
- If I hit 1st crack earlier (for this roast 7:30), would this allow me to have 2 minutes development time and still retain 12%ish weight loss? If so, how do I shorten the browning phase – with a higher or lower charge temp? Something else?
- What is an acceptable temperature range increase from 1st crack to drop? I get nervous when the temp starts rising too fast in the development phase. Is this not that important either?
- A roaster friend of mine told me that around 400 degrees F is optimal for 1st crack. Is this a good gauge or is my 393 F okay?
Hi,
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For me, I use weight loss % to check consistency between batches. If I’m happy with how a roast tastes, I’ll try to match the weight loss on the next batch. I use color the same way. I have a Tonino color meter. It was helpful to have an objective measure but I found that keeping an eye on weight loss % and development time gives me a pretty good guess as to how the next batch will taste. I’ve made batches that are too acidic in a range of weight losses and colors. Just in general, I found that more time at the higher temperatures helps reduce that acidity.
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I wish I had an answer to that too! I struggle with making the browning phase shorter on my roaster and keeping an overall short time. If I can get a 40% dry, 40% brown, 20% development time I consider myself lucky. I find it much easier to do if I have a longer roast time, but i think the light roasts can lack flavour if it goes on too long.
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I think you’re right, if the temperature rises too much in development phase the light roasts don’t taste great either. I end the roasts within 5 -8 degrees celsius generally. I don’t know if that still qualifies as light roast or if it is nearing medium roast levels… Sometimes I alm lucky to end it lighter and those turn out really nice, but I find it hard to repeat those roasts.
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On my gauges, 393 would be low and 400 is a bit closer to my normal… up until about a year ago, my first cracks were more in the 393 range. I don’t know what caused it to switch,
Anyhow, I hope this helps, I hope your roasting goes well.
Thanks for all your thoughts, I appreciate it, very helpful!
You’re welcome. Also fwiw, I think that it’s hard to bring out the subtler flavours in light roasts. My current thinking is that it really depends on the beans more than roasting technique. I don’t normally buy really high grades coffees, but I recently sample roasted a 91 point coffee and it was shockingly fragrant compared to a 87.5 point coffee that I make more often. I haven’t sampled a vast amount of coffee, so I could be wrong, but what I read about light roasts bringing out subtler flavours, and losing some of that if it’s roasted a bit darker, made a lot more sense to me after trying the 91 point coffee.
Yes, I wonder about this too. I usually get higher rated coffees though, and still am not wowed by the flavors.
When I find my sweet spot with a roast preferably between 12.6 - 13.6% weight loss with a development time of 1:20 - 1:45 and an end temp of 413F - 417F I am generally pleased with the taste result. Mastering it every roast is the roasting journey of cause and effect we all find ourselves in. I am a home roaster and enjoy trying all kinds of different green coffees, so I seldom buy a large enough quantity of the same coffee to completely get it dialed in, but am able to get close most of the time. I have discovered that 500G batches are easier for me to control than a 784G batch which also gives me more batches to experiment with.
Any batch I have roasted that finishes with 12% or less moisture loss seems under developed.
I recently roasted an anaerobic processed Columbia Finca Milan Nitro Caturra
that wowed me with huge flavors and excellent creaminess, I highly recommend it.
I purchased this green from Bodhi Leaf Coffee Traders. It was a bit pricey pushing $20lb, but well worth it and if you purchase $59 or more the shipping is free.
Have fun with your roasting journey!
Thanks Larry. If I go more than 1:30 after 1st crack, it always has over 13.6% weight loss. I usually get around 12% if I do 1 minute after first crack. At what start temperature would you charge your 500g sample?
I start the preheat temp at around 490F for 500G.
It seems like there are no two Bullets alike :-/
I think you might be right I can never duplicate others’ profiles without some changes.
Has anyone tried a profile with a high PH and a higher fan setting, lowering the fan setting after yellowing, then bumping fan speed near first crack? The idea being to shorten the middle part of the roast relative to drying and development time.
Hi @vigil_vessoul
I would like to add that for me weight loss is something I log and pay attention to, but it’s not as important as the overall flavor result.
When I think about weight loss, I remind myself that the available weight to lose varies with moisture. Are you measuring the moisture content of your green coffee? Without that data point, weight loss is only so valuable. If the green has 14.5% moisture before roasting, it has more to lose during the roast. A coffee with 10.5% moisture before roasting has less water weight to lose. So the 12ish% loss that you mentioned is quite relative.
Trust your palette more than the weight loss. The flavors that you are describing and the lack of sweetness lead me to suggest going for more development. Try increasing the DTR without increasing the end temperature. Try increasing the end temperature. This could even be achieved with a slower overall roast and the same DTR and end temperature as your current profile.
Definitely log the weight loss, but don’t let it rule you. Hope my perspective is helpful. To me tart and lacking sweetness sounds like an underdeveloped profile. Of course the green coffee you have is the ultimate determining factor as others have suggested.
Hi, thanks. Good point about the weight loss ambiguity. Good to hear all the similar advice.
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