First roast - grassy taste (chaff??)

[canadaroaster]

Hey,

I did my first roast today. Its a Yemen Iryan coffee. I then tasted the coffee and there is this grassy taste I used to taste when I used the popper. I am thinking its due to the chaff left on the surface of some of the beans? what do you think?

Could it be the fan? I don't use a variac so I open and close the fan from time to time. I was thinking maybe I should keep the fan open throughout the roast to take out all the chaff. what do you think?

[Adondo]

Grassy flavours are usually a result of inadequate developement. How long was the roast and at what temperature did you finish at? And yes, keep fan open. A variac/regulator of some kind is veeery handy i must say. Not only do you get more precise measurements but you also avoid the issue of chaff getting stuck in the pipe as a result of too narrow space with the damper. Good luck!

[kctremel]

True, underdevelopment.  Did you record with artisan? Don't have to use variac, if wanted to go cheaper you can buy a light dimmer or fan controller...but I recommend variac.

[canadaroaster]

Thanks for your feedback guys!

I tried the roast again this time i managed to fix the BT (I needed to hold the wires for it to work). The grassy taste still significant. Can you take a look at my profile and let me know what you think I am doing wrong?

[kctremel]

it kinda looks like you baked them, you should look at artisan coffee alliance and see all the graphs people showed there to compare them.  You should really plot your fan/power in artisan as its a lot easier to help, but id start off with more heat at first then slowly decrease it with slowly increasing fan speed.  Those yemens should not be grassy at all.

[SusanJoM]

If you will upload a .png file, it would help. 

In Artisan File > Save Graph > Full Size.

[canadaroaster]

I noticed all the graphs of roast done right in alliance website and in this forum have the BT drop almost 100C after charging the beans mine didn't drop more than 50C before flattening at around 150C which seems too hot. How do you guys do it? do you drop the heat to min as soon as you charge?

To get the heat to 220C at the start before charging the beans took a while (that is with the fan on and the drum rotating)
 
You are right Kctremel the beans are good I know this because I've tried getting them roasted at a professional roaster and this grassy taste was not there.

thanks SusanJoM for your input better to get a pic instead of a pdf from artisan.

[SusanJoM]

One more point from me:  if you would put into your profile whether you are using a solid drum or perforated it would help.  Having recently acquired a solid drum after using a perforated set up for two years I can tell you that they are DIFFERENT ! ! !  A HUKY is a HUKY is a HUKY, and knowing one can help know the other, but the real guts of the matter:  how heat and air combine to make a successful roast???   Totally different (IMNSHO)

[canadaroaster]

Thanks Susan, I should've mentioned I am using a solid drum.

[kctremel]

have it heat up for 10 mins, turn off the flame or the smallest you can get and when it reaches drop temperature drop the beans in and wait for the turning point then blast the beans with heat and slowly decrease when temperature rises more and more.

[renovator20]

I Have been roasting with the perforated drum and am making pretty good coffee. Does the solid drum help develop better flavors?
Thanks for any opinions.

[kctremel]

I don't think its a difference of better this vs better that, I think the flavors will be different but that is only for you to try and decide, as peoples tastes buds are vastly different. I have both and will try the perforated once I get the hang of my solid. 

[SusanJoM]

I Have been roasting with the perforated drum and am making pretty good coffee. Does the solid drum help develop better flavors?
Thanks for any opinions.

If you find more than 2 or 3 people who have actually used both I would be surprised.

[edtbjon]

I Have been roasting with the perforated drum and am making pretty good coffee. Does the solid drum help develop better flavors?
Thanks for any opinions.

I've used both and I don't think that either one is worse or better than the other. They just need a somewhat different approach to how you operate it. As it takes a while (read: months...) to figure out how to get the best out of a particular setup, it's hard to really make a side by side comparison.

[Gregr]

A couple things about the grassy taste-- first is those Yemens are much improved after a good week of rest.
Second is the comments about development are right on-- and you chose a tricky bean to learn this lesson on. Try for at least 5 minutes to 300F/149C and even 5:30 would be just fine. Going too fast in that first phase leads to beans that have too much moisture inside and not enough on the surface- kinda like a steak that has a burnt crust and is raw in the middle.
Looking at your graph it seems like maybe the probes are not fully in the bean mass maybe? Usually the bean temp at the turning point is 93-100C not 150C so something is not right there.