Tipping/burning/burnt flavor no matter what

[coffeechris]

I dont want to keep pushing it but are you sure its not your process when making a coffee? Quote me if im wrong too but maybe your take on burnt maybe different to my take on burnt and thsi may differ to others aswell? From those photos and the graph it looks pretty good to me. just wanting to help the best i can.

[DesigningByCoffee]

Hi James
They certainly look nice in the pics.
I suppose all you can do is go by the taste - not the 'ideal' times. I'd put aside the 11mins - and try some longer roasts :-)

Here is a copy of my latest profile - but you'll notice I'm hitting 14mins to 1C, & 18mins all up. Similar shape to your curve just longer. From multiple runs, I've found if I go much shorter it gets sour with less body - and obviously requires a lot more heat to do it, running the risk of charring. You'll also notice to that it never goes over a rise of 20deg/min. But this particular roast (a mocha java blend) I'm currently drinking is spectacular! Very rich, dark choc.

To get that result, you can see on the profile where I increased the temps. Down the bottom are my gun settings - but you can covert these to generic inlet temps on the LHS table - this temp would be gun independent. But this is basically a gentle warm, then slow consistent climb (which requires increasing temp input to achieve) all the way to 1C.

I guess all you can do is keep experimenting :-) - but if your tasting burnt, I'd go longer in time - and see what happens!

Matt

[Bames]

Hey all,

I tied another roast yesterday, doing a few things differently. I added another "arm" to the paddle so that then beans would agitate more, and went up from 330gm to 400gm to see if that would make a difference.

I started off really gentle - a rise of about 5-10 degrees pm for the first minute, then gently up after that and didn't get a rise of 25 degrees pm until about the 4 minute mark at around 70 degrees. maintained that rise until about 150 degrees where I let the rise ease off again so it gradually went down to about 10-15 degrees PM by 190, and about 5 degrees pm by the time 1st crack hit. After that the rise was around 3-4 degrees PM up to second crack. I pulled it out just it was getting a few snaps of 2nd crack here and there in the cooler.


20121004-Brazil Yellow Bourbon by jamespbeasley, on Flickr

I felt like it smelled better than previous roasts so had good hopes for it, but tried one pull this morning and still the same thing - burnt taste.

I have a few photos below of the roast. As you can see the colour is good and they dont look burnt - until you crack one in half and look at the middle. It's like a reverse steak where the centre is dark and the outside isn't - and there's a big burnt tip on the end.


_MG_2733 by jamespbeasley, on Flickr


_MG_2751 by jamespbeasley, on Flickr

On the photo, the inside of the bean doesn't look quite as dark as the real bean - the contrast between the dark centre and lighter outer is a bit more so.

I seriously don't understand what I'm doing wrong - I don't feel like I can be any more gentle with the heat casue first crack would be too late then, but how do I stop the tipping/burning? Next thing I'm going to try is to have the HG a bit further away from the bean mass, cause maybe the heat i hitting the beans to directly... I don't know.

The annoying this is when I first out the corretto together I wasn't having these issues. No DMM, not much practice, and I was cranking out good tasting roasts (albeit not perfect - but definitely better than now). Is there a chance that maybe my HG has gone funny?

It doesn't seem like others are having this much trouble... i must be doing something wrong.

[commanda]

James,

My roast profile goes something like this. Starts off at 30C/min, by 150C it's down to 10C/min and stays there to 200C (first crack).
After clearing first crack I back off the heat input a bit, and try for 5C/min up to my arbitrary end point, lately been 221C.

The description of your rate of rise from 150-200 sounds way too fast.

Amanda

[DesigningByCoffee]

Hi James
Like you, I used to try and surf temps rise rates - but found it terribly frustrating! The gun/beans don't respond that quickly - an 'ideal' profile curve doesn't necessarily look anything like what you do with the gun.
If you want a bit of an idea about my technique (which is actually more important that the output profile IMHO), here is a recent thread I posted on inlet temp profiling - it sounds complex, but when you get down to it is really simple - and has been a real 'aha!' moment for me. In reality now - I only adjust my gun a couple of times in th roast to get consistent great results - and let the curve/temp rise do its thing. In that thread is a table of what I do when in the roast - and a PDF spreadsheet i use you might find interesting which has a blank sheet I fill in, and one that has a graph of my inlet temps - and when I increase and decrease them.

http://coffeesnobs.com.au/home-roast...profiling.html

As to the 'burnt on the inside' thing - I suspect too much heat early on could account for this - kind of like too-hot an oven will dry out the inside of a pavlova, rather than making it nice and mushy - but still might not burn the outside. Just a guess.
But i've certainly found from experience that if a roast is too hot and too fast - you can get that overdone/underdone taste happening.

But keep at it - you're really close - and when you nail a good one - you'll know it!

Matt

[Bames]

Thanks Matt - I appreciate the advice! I have watched your video of your roast and sort of tried to follow what you do a bit, but would you mind posting a photo or even data of one of your roasts for me to have a look at?
I tend to concentrate most on the temp increase rate when i roast, and aim for roughly the following - comments appreciated:
20-50 degrees: 13-15 degrees per minute
50-150 degrees: 25 degrees PM
150-180 degrees: 17-20 degrees PM
180-195: 20-25 degrees PM
200+: 3 degrees PM
I try to adjust the temp input gradually up and down to achieve this, taking it up half a notch at a time on the ozito (it has about 13 notches - I don't usually go higher than about notch 8 at the most).

Interesting Matt what you said about burned on the outside and not as well cooked on the inside - I actually usually find is the other way around - at least it looks that way when I crack a bean in half to have a look. Looks dark brown/ black-ish in the middle and lighter brown on the outside. Does anyone know what that means?

I did a brazil roast yesterday - when I cracked a couple of beans in half this is what I saw. I'll try to take a photo.

[DesigningByCoffee]

Hi again James
The other thing I noticed is your very quick/strong/high power ramp technique.
My general technique is to start at around 1/2 power (350 deg on a 650 deg gun) then increase to 400 deg at 130deg measured on the DMM, then 450 deg at 160deg on the DMM, which is still only 2/3 power. Then I drop back to 400 just before 2C (195) then drop back aging to to 350 at the end of rolling 2C (210deg). I have in the past played around with continuing to increase the temp ramp (up to 450-500deg on the gun) heading towards 1C - but this can give a dry/brittle/burnt flavour to the final roast, even when pulled early, ie well before 2C. While this doesn't vary the profile hugely to look at on paper (might only be by a minute at this late stage) I think the higher late temps must combust the inside of the bean a lot and break down the goodness locked inside :-)
So maybe go a bit more gently - start with a gentler start temp, then give it a healthy time to warm the beans (half way or so to 2C -120-130 dge) then gently ramp - but not too much. Shouldn't need to go to full power.
Your accurate tasting descriptions are really helpful though - you'll be amazed at the difference in taste with slight adjustments like these! I can almost taste your pain - I've been there before!!

Matt

[DesigningByCoffee]

Thanks guys - I'll keep trying, i'm just gettin really frustrated.
The problem with that Andy, is that I get both burnt and sour tastes in my coffee!

Hi James
Looking at your profile, I think that the tastes you are getting would be solved by following Andy's advice.
If the input temp is too high, the sour would be likely come from the inside of the bean being un-roasted - the burnt from the outside being charred (think cooking a thick sausage with the BBQ plate too hot). A longer, gentler roast would cook into the bean, while preventing charring on the outside. Try either reducing the gun temp (if adjustable) or lifting it 2-3 cms higher (slightly above the lip of the pan). keep these two flavour tips in mind, and adjust to suit. When the taste gets thick & muddy - the roast is too gentle/long.
BTW The position of your gun - front corner / slight angle - sounds about right :-)
Look forward to hearing about the progress!

Matt

[coffeechris]

Have you thought that it may not be the beans your roasting but the process and way you are using to make the coffee? Have you tried some good quality roasted beans say from Beanbay? As Saeyo said if you can post a pic on here so we can have a look at them

Your graphs don't look to much unlike mine, Like what Andy said is aim for first crack around 10-11 and drop around 4 mins after.

Cheers

Chris

[Bames]

Thanks guys - I'll keep trying, i'm just gettin really frustrated.

If it tasted dark then you roasted too long and/or cooled too slow. Easy as that!

The problem with that Andy, is that I get both burnt and sour tastes in my coffee! So usually there will be a bit of sourness up front; which then reduces in the mid-palate; but is finished off with burnt end palate and aftertaste. As well as the sourness up front I also get big bubbles that form in my milk over the first few minutes after pouring a cap - which leads me to believe I am both under and over roasting! I have tried to vary roast length (to an extent - will experiment more), and when I roast not as long or deep, the only thing that really happens is the taste swings more to the sourness - but the burnt after taste is still there!

I had been aiming for about 9-10 for first crack and then 2-3 degrees per minute after that. I'll try a slower ramp to first and maybe 3-4 or 4-5 degrees per minute to second crack and pull a bit earlier and see how I got.

But just also wanted to ask - could it have anything to do with position and angle of gun into bread pan? I position the gun in one corner just below the top of the bread pan and angle slightly (like 10 degrees) towards the diagonally opposite corner.

Also, are you supposed air out the gun after use to try to get out coffee smells? Like let it run on a low heat just in the open air for a few minutes after roasting?

[saoye]

Exactly. You need to play around with the roast and adjust accordingly to your taste. Any chance of posting some photos of these roasts that taste like ash? I'm wondering how dark you're roasting. I tend to stop just before 2nd crack or immediately after. I assume you're using the one way valve bags to store after roasting? Also, why wait a full week? I tend to like to taste each day after the roast. Some beans I find are perfect within 1 week of roasting, others needs up to 2 weeks to settle (like some Indonesian beans I have).

If it tasted dark then you roasted too long and/or cooled too slow. Easy as that!

Your 2 graphs are very similar so getting similar results is what you should expect. You need to make a change.
Try a slower ramp up to 1st crack (aim for 10-11minutes) and stop the heat earlier (4 minutes after first crack).

You are close.. just a little tweaking and the results should be great.

[Andy]

If it tasted dark then you roasted too long and/or cooled too slow. Easy as that!

Your 2 graphs are very similar so getting similar results is what you should expect. You need to make a change.
Try a slower ramp up to 1st crack (aim for 10-11minutes) and stop the heat earlier (4 minutes after first crack).

You are close.. just a little tweaking and the results should be great.

[Bames]

Hey all. So got my DMM and done 4 roasts. I still seem to have the same problem of quite bad burnt flavours in the roast. I have included 2 graphs, one is Brazil Yellow Bourbon, the other is Harrar. The Brazil tasted a bit better than non-DMM roasts, did 2 Harrar's (one the probe fell out and the other was - no real improvement). I also did a gambella, which on the other hand was shocking. Horrible burnt taste - worse than without the DMM. I don't understand, it's really annoying me.

I pulled it out about 20 seconds after 2nd crack (was trying for on the first few snaps but couldnt hear it). the smell after roasting was beautiful, smelled nutty, caramelly and smooth. Left it to rest for 1 week and just opened the bag again. Instead of being hit with nutty caramelly smells I was hit with charcoal. After running a shot through my machine and splitting the shot into 3rds, the dominant taste in all 3 sections of the espresso was ash. This is driving me insane and I'm seriously thinking about chucking in the corretto.

[img]
20120909-Brazil Yellow Bourbon.csv by jamespbeasley, on Flickr[/img]

[img]
20120915-Harrar by jamespbeasley, on Flickr[/img]

[malfi]

Hi James, I'm a newby roaster using a corretto and the $10 temp probe from Jaycar. I was having exactly the same problem with basically burning the beans. It has taken about 8 roasts to realise this, and I ended up changing the corretto to have a custom lid with 2 holes. One for in and one for out. It fits snuggly over the top so no other heat loss. This made it necessary for me to reduce the heat from the Ozito HG right from the start, and the temp control then is much better if you keep a close eye on it. I'm following Peter Forster's excel guide, but just a little (1-2C) under his profile. Last batch I did with my new set-up was the Indian Longberry and it's pretty close to spot on I'd say. No charcoal/burnt flavours. I'd recommend re-trying the cover over the BM, and also the DMM would be great but I don't think it is essential. Although after a few more batches I'll prob get one too! Good luck

[coffeechris]

James,

I have found and learnt that consistancy is one important key roasting, purchasing and using a data logger can only help you acheive consistancy with your roasting. I orignally bought a probe and temp gauge from an outside source, then finally bought the data logger from beanbay here, wishing I had have done that in the first place. It can only help you get better.