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allenb
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· 04/02/2020 4:50 AM
Morning Ed, I haven't done any green coffee hoarding yet but am hoping the supplies don't end up like the toilet paper isles!

snwcmpr
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· 03/31/2020 2:53 PM
Hey Ed. Thanks. roar

homeroaster
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· 03/31/2020 11:21 AM
Hey quarantined home roasters! I hope you have great coffee! If they have a run on coffee, I hope you're set with your great home roast! Find me on Facebook! Ed Needham

snwcmpr
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· 03/25/2020 11:49 AM
New Rochelle in the news. I think of you every time I hear it. ... Please stay safe.

allenb
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· 03/21/2020 7:36 AM
Good morning homeroasters morning Everyone is hopefully staying healthy through this. Hang in there and stay safe!

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Wonder if I'm Baking
fauzi
Hi there,

First post... A Hello to all of you from Karachi, Pakistan!

Been using my Genecafe for about a year now, and have had mixed results. Been trying to read up on it, but recently have been getting nothing but bad results. Will try to explain what's going on, so I may get a bit long-winded... But need to put it all out there! :)

Symptoms:
Quick, sour extractions on my Rancilio Silvia, groudn finely on my Rocky.

I had been faulting my grinder and machine, but recently realized that i was able to get perfect extractions from store-bought stale coffee... Started focusing on my roaster and realized that I am not getting to the temperatures that I'm using as nodes in my profiles. I deal in deg celsius here so will convert for the forum below:

My profile:
Preheat on full power for 5 min and quick dump beans
302 F for 5 min (Drying)
446 F for 4 min
464 F for 1.5 min
482 F until 10 seconds AFTER FC
455 F until desired roast level
1-1.5 minute manual cool cycle (colander on fan) to room temp.

Usually, I get to say 446 in the 2nd node by towards the end of 9 min. Recently, I have not been able to get there at all.... In fact, my temp reading at 9:11 says 411.8.

I'm no expert, but the beans don't seem like they're expanding as much as they should either.

At the end of 48 hrs of resting, I'm getting 12-15 second blonding espresso shots...

Do the symptoms sound like I'm baking the bean?

Appreciate the help!

Fauzi
 
jkoll42
Welcome! That's really cool we have a member reporting in from Pakistan!

I do not have a GC so I cannot comment directly about the temp profiles although others here certainly can.

If you are able to grind store bought beans fine enough to pull an ok shot then you are correct - it should not be the grinder or machine. Are you hearing first crack currently? It sounds like you are not getting the heat output you should be getting. Beans that are roasted very light are basically impossible to pull shots with. I had a batch of my normal beans where there was an issue with my thermometer and the roast was light and baked and I couldn't pull a shot to save my life. Had to dump the beans in the trash.

When you look at the bean where the crease is, is the bean flat across the crease or rounded and expanded?

Check out the underroasted pic here

http://www.home-barista.com/home-roas...13587.html

Jon
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
seedlings
+1 for too light of a roast. I almost always want to hear a little bit of second crack for espresso. I will add that the grind setting may have to be changed as often as every day, and certainly changed for every bean.

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
fauzi
Jon, Chad,

Thanks for the responses. And yeah... All the way from Pakistan. Frustrating as heck as we're a nation of tea drinkers and thus very difficult to find a decent coffee shop or supplies, machines or even green beans. The only ones I have are the ones that I sources online. And man, freight and duties really pinch.

Dont know about the flat or rounded bean. Will post a pic later tomorrow.

I will tell you this. After reading through this site I plugged the roaster trough a voltage stabilizer. That did wonders to the ramping times. I was getting to the nodes with time to spare. I use the Roastmaster iPhone app and will see if I can post the graph of my roast tomorrow. The end result is resting... Took it through to a good 30 seconds after the sc. Will report back with pictures and after the degassing is done.

Fauzi[mail][/mail]
 
John Despres
Welcome!

Your airflow may be impeded. Turn your roaster over and make sure the screen at the intake is clean. Vacuum it to be sure.

Then take you chaff collector off, disassemble it and clean it as well.

That may help.

John
Respect the bean.
John Despres
Fresh Roast 8, Gene Cafe, JYTT 1k, Quest M3, Mazzer Mini, Technivorm, various size presses and many more brewers.
 
www.sceneitallproductions.com
fauzi
Ah you're probably right, John... Very dusty here.

Will give it a shot tonight. Will look for instructions, but if anyone has a diagram of how to disassemble the chaff collector, would appreciate it.

Had a quick shot of the Nicarguan Uru Estates that I roasted last night. 12 hours after roast, so not rested nearly enough, but initial prognosis is good. Still a quick extract, but we're talking 19 seconds to blond as opposed to 5.... Will wait now for another day or so.

Thanks guys...

Fauzi
 
fauzi
I meant to ask if the top of the chaff collector just pops off? I have the larger black one.

=Fauzi
 
hazbean
I haven't used my GC for a while, but I do have the large chaff collector and taken it apart a few times.

The top just pops off (with care). There are four screws, I think they are the same but I kept track oof where each came from just in case (they are not all the same on the small collector).

The metal "struts" also pop off, a little effort is needed (I was a bit apprehensive the first time but it went back together fine).

Once apart, it is very easy to clean, and seems less prone to attracting fine "dust" than the small collector.

Make sure to vacuum the air intake (as John said), it is critical.

I also found that using a voltage stabiizer / variac made a big difference.

Best of luck!
 
fauzi
Hi there,

Almost 40 hours after roasting, still no love... Don't know why I thought the roast was better initially....

I've attached a pic (hopefully, if I can figure this out)dl.dropbox.com/u/311390/Coffee%20Beans%20-%20Nic%20Uru%20Estates.jpg

Profile was the basic one above, and the temp readings I got (off the inbuilt thermostat / no external probe), are graphed as attached.

dl.dropbox.com/u/311390/Roasting.jpg

FC @12:19
Turned down the heat 10 seconds after FC
SC @ 16:04
EOR @ 17:40

Reason for going almost two minutes into SC is that it didn't look like I was acheiving the level / color I wanted.

Comments highly appreciated... Starting to get to the end of my wits here! :(


Fauzi
 
jkoll42
Can you choke the machine by grinding finer?
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
seedlings
When roasting dark(er) for espresso, reduce the 'drying' time to give just a bit more moisture into second crack. 300F for 5 minutes is too long (or would be too long on my roaster). Bump up the temp at 3:00 and keep the rest of the roast the same.

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
troposcuba
Chad, are you saying to skip the "drying phase" altogether and just go to the first step of the roast profile?
I am pretty proficient at roasting for other methods, but have just begun my quest for the ultimate espresso recently. I am having to learn a bunch of stuff I never thought about for a new roast goal. My local roaster (who is very good and helpful too) told me that he likes to try the stretch the whole roast out a bit for espresso.
Sean
 
jkoll42
Have you had problems with extraction with beans of multiple origins or have all these problems been from the same bean?

Have you tried grinding finer?

Have you adjusted the Silvia OPV down from 12 bar?
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
seedlings

Quote

Burner0000 wrote:

Quote

troposcuba wrote:

Chad, are you saying to skip the "drying phase" altogether and just go to the first step of the roast profile?
I am pretty proficient at roasting for other methods, but have just begun my quest for the ultimate espresso recently. I am having to learn a bunch of stuff I never thought about for a new roast goal. My local roaster (who is very good and helpful too) told me that he likes to try the stretch the whole roast out a bit for espresso.


15min - 18min is ideal. :)


15-18 min is fine, but how you get there can change things.

I'm just suggesting that the first 5 minute segment at 300F be reduced to 3 minutes. Since I don't have any experience on a Gene Cafe, this may make the coffee worse. I measure hot air temperature and bean temperature on my roaster. I charge the beans into a 400F preheated RC, and the air temperature only goes up from there. By 5 minutes into a roast my beans are over 300F, and the air temperature is near 550f, so I'm coming from a whole different animal.

Reducing your first phase by 2 minutes won't necessarily shorten your time to second crack by 2 minutes. As always, the advice is free whether it's good or bad ;)

On your graph if I draw an imaginary line from 70F (original bean temperature) to 400F at 12 minutes, the beans won't have hit 300F until maybe 8 minutes into the roast. This seems long, and is why I suggest reducing the time at 300F air temp.

CHAD
Edited by seedlings on 05/10/2012 3:51 PM
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
seedlings

Quote

jkoll42 wrote:

Have you had problems with extraction with beans of multiple origins or have all these problems been from the same bean?

Have you tried grinding finer?

Have you adjusted the Silvia OPV down from 12 bar?


12 bar is just an emergency value so the machine won't explode. The grind will be the limiting factor for ~9 bar. I had a vibe pump gaggia and played around with the OPV only to find this out. YMMV.

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
jkoll42

Quote



12 bar is just an emergency value so the machine won't explode. The grind will be the limiting factor for ~9 bar. I had a vibe pump gaggia and played around with the OPV only to find this out. YMMV.

CHAD


I don't want to threadjack this with a technical espresso discussion, but... I just love being technical :)

The Gaggia's (and Silvia's, et all) used to ship with a 9bar OPV. The switch to 12bar only came when they started to POD certify the machines (since the POD companies build their product to a 12bar spec). Theoretically, it is possible to get the right grind to produce 9bar but in practice it is next to impossible. Vibe pumps vary the flow based on pressure which adds a whole other set of variables. Higher pressures (12bar) initially have slower volume but tend to lead to channeling in the puck ... which leads to a drop in pressure and higher flow rates (nasty!). By setting the OPV to bleed off pressure above 9bar (which is ideal for extraction) you greatly reduce the channeling chances and allows you to tune a grind that closely matches the preset 9 bar without blowing the puck apart.

So... I agree with you Chad - you technically could get a grind to hit 9 bar and the OPV is definitely in place to prevent catastrophe... but I would still adjust it down as it makes the machines much easier to work with and gives a much larger margin of error especially with a SBDU machine that already has unstable temps intrashot.

<<<<<END THREADJACK>>>>>>>
Grin

So did ya try to grind finer???
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
fauzi

Quote

seedlings wrote:

When roasting dark(er) for espresso, reduce the 'drying' time to give just a bit more moisture into second crack. 300F for 5 minutes is too long (or would be too long on my roaster). Bump up the temp at 3:00 and keep the rest of the roast the same.

CHAD


CHAD,

Interesting. Will certainly give it a shot, as I can't seem to get the beans into a roaring 2nd crack.

A couple more questions (excuse the noobness!):

- Discounting airflow deficiencies, why would I not be able to get the beans into an active 2c, when I have been able to do so in the past? Weather?

- I have noticed (and this is just a visual observation and not scientifically measured) that the beans tend to look smaller during the roast than I remember. Could this be due to the fact that I have dried all the good stuff out by extending the drying phase too much?

- This directly leads into preheating the roaster. I preheat to 482 for 5 min, and then put the beans in as quickly as possible. As you can see from my graph, by the time the roast started, it was at 230 or thereabouts. Is there an ideal temp to pre heat to?

- And I've looked for threads about a temp probe into the GC, but as a general rule, I've found that people have not been able to due to the off axis movement. Any updates that you guys may know of? If so, I'd really appreciate being pointed in the direction of a source.

Fauzi
 
fauzi

Quote

jkoll42 wrote:

Can you choke the machine by grinding finer?



jkoll42,

Nope. That's my problem, and that's what led me to thinking that the grinder is faulty. All my roasted beans are now like this... quick blonding shots.

Fauzi
 
fauzi

Quote

jkoll42 wrote:

Have you had problems with extraction with beans of multiple origins or have all these problems been from the same bean?

Have you tried grinding finer?

Have you adjusted the Silvia OPV down from 12 bar?


jkoll,

I have had this issue with ALL beans that I roast. This recently has included Nicuraguan, Colombian, and Sumatran.

Yes, I did lower the OPV down to 9, but put it back up when it didnt' make a difference.

Fauzi
 
fauzi

Quote

Burner0000 wrote:

Hello Fauzi!

How are you storing your green and roasted beans?
I have also found when roasting and pulling shots that certain beans just aren't good on their own for pulling espresso shots. I Love brazil because it produces lot's of crema. I would also double check tamping to make sure your giving it 30 lb of pressure then a second 15lb tamp. to eliminate wasting beans try roasting a smal batch of your nicaraguan into roaring second crack and see if you get some oil outside the bean, let sit and try again after resting.


Burner,

Roasted beans I'm storing in an airtight contiainer which I open daily for a few minutes to degas for the first couple days. Greens, however, are stored in the jute bags that they came in.

I don't know if I can post a link to my thread at Home Barista, but I posted there about the same problem, thinking the issue was my grinder. In reply, someone said to improve my technique. So I got down to it, and they were right. Since then, I have improved to the point of being able to consistently extract excellent (relatively speaking) shots from store bought coffee.

Will certainly try your idea of getting some oil on the beans, but I have a feeling that by the time the first crack has happened, I've already done something wrong... because the past few roasts have just kind of been sailing into 2c and not much seems to be happening to the bean.

Will post back.

Appreciate the time to respond.

-Fauzi
 
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