Length of Drying Phase

[Dogalish]

Hi, I've done about 25 roasts on my Huky so I'm still really new to it all and am learning how to control the machine at the moment rather than trying to perfect a particular roast profile or do anything too advanced.   I have a solid drum and I'm using a charge weight of 350g and a charge temp of 180C in every roast and then experimenting with different airflow and heat combinations to see how those affect the progress of the roast.   

I've noticed that when charging 350g at 180C I reach the end of drying phase (150C on Artisan) at about 6:30 minutes and this doesn't change dramatically regardless of the airflow/heat combination I use.  I don't have a Variac but I am using a fan speed controller.

I think the quickest end of dry that I've managed is 6:08 when going straight to 4KPA after 30 secs (4KPA is the max I can get on burner that comes with the Huky).   My question is that when charging at 350g/180C,  should I be able to achieve a faster drying phase or does 6:30 seem about right?   
 

[SusanJoM]

Could you upload the .png file for that roast so we can see it?

And why have you chosen 180C as your charge temperature?

[Dogalish]

Hi Susan, thanks for replying,  first time uploading a PNG file, hopefully this worked....

In this roast I went to 4kpa 30 seconds after charging then made the following heat adjustments:

8:30/175C - 3.5kpa
9:45/190C - 3kpa
10:30/202C - 2kpa
11:00/206C - 1kpa

The 180C charge temp is slightly arbitrary but is loosely based on the charge temp used by a pro roaster I know.    I have experimented with higher temperatures but was concerned about scorching and going much lower would probably extend the drying phase even further?   So I settled on 180C with the intention of keeping that the same and tweaking the other variables first. 

Thanks!
 

[SusanJoM]

Much better.  Thank you.

Was that pro-roaster using a HUKY?  The HUKY is both similar and dissimilar to a pro-roaster, and it's most glaring dissimilarity is its lack of thermal mass. 

I have just started using a solid drum HUKY, myself, so I am no expert, but 220C seems to me to be an ideal charge temperature for 350 gm.

Here's my most recent roast (my fifth using the solid drum).

[edtbjon]

I usually charge even lower (400g and 140C) and usually do hit DE at around 6.00 (getting my TP in the low 70C or so). I also have the burner off when I charge and turn it on at around 1.10min into the roast. You don't say what you do with the airflow, but I start my roasts with a low airflow during the whole drying phase. Not that the beans need the airflow during the drying phase, but the burner does need some air to be more efficient.
There's a video on how to set airflow at MillCityRoasters, where Dave uses a cig.lighter to get it right. That's a good starting point.

[Dogalish]

Much better.  Thank you.

Was that pro-roaster using a HUKY?  The HUKY is both similar and dissimilar to a pro-roaster, and it's most glaring dissimilarity is its lack of thermal mass. 

I have just started using a solid drum HUKY, myself, so I am no expert, but 220C seems to me to be an ideal charge temperature for 350 gm.

Thanks Susan, I had experimented with some higher charge temperatures during my first few roasts with the Huky but found that I was getting what looked like some scorching so reduced the charge temp down (sorry should have mentioned that earlier!).   But it looks like others manage to charge at high temperatures without any scorching so the scorching I saw may well have been occurring later in the roast.  I'll do some more experimenting with higher charge temps and see how I get on.

Thanks for your help!

[Dogalish]

I usually charge even lower (400g and 140C) and usually do hit DE at around 6.00 (getting my TP in the low 70C or so). I also have the burner off when I charge and turn it on at around 1.10min into the roast. You don't say what you do with the airflow, but I start my roasts with a low airflow during the whole drying phase. Not that the beans need the airflow during the drying phase, but the burner does need some air to be more efficient.
There's a video on how to set airflow at MillCityRoasters, where Dave uses a cig.lighter to get it right. That's a good starting point.

Thanks edtbjon, I've read some of your posts about your success with using a low charge temp and this is something else I will try.  It sounds like hitting DE at 6:30 using a 350g/180C charge isn't too far off the mark so that's good to know.   I look forward to experimenting with some lower and higher charge temps!

[cgriffith]

I have been roasting with Huky for a few months; solid drum.  I usually charge 400gm at 200 - 210 C.  I plan on doing some testing of this, but the one factor  I have found that effects DE time the most is when you apply heat after charge. 

My first couple of roasts I did not apply any heat (burner off) until TP was actually reached.  TP was coming in at around 2:00;  DE was consistently around 7:30.  I was thinking this is too long, so I did some research.

After watching videos made by Dave Borton at mill city roasters, I started turning burner on at 1:00 into roast (i.e. a minute after charge).  Then TP was closer to 1:45 and DE around 6:30.  I still thought this was too long.

Now, and until I try something different, I turn burner on as soon as I charge and slow ramp temp up to 4Kpa in the 1:30 time.  Thus, now TP is consistently at 1:30 and DE is around 6:00.

Is this right?  IDK.  Just FYI

I was planning on keeping my current method the same only changing charge temp to see if that affects DE and/or when I need to turn burner on after charge.  If you do this before I do, I'd be interested in seeing your result.

[hankua]

For the OP, 5-6min EOD is pretty normal so it sounds like your trying to shorten up the total roast time?

If thats the case after EOD, go "wide open throttle".  Wide open is using maximum gas/heat and the air setting that achieves the highest ROR.

Another suggestion is if your using a $5 dimmers, switch it out with a router controller that should have more range.

If i can get a shorter time to EOD using the same stove/roaster means something else in the system is different. The exhaust system plays a big effect on how the roaster operates. Location is another, where outside wind or cold environments could affection slow EOD.

Turning off the burner is not necessary, unless one is going for a high charge and low TP temperature. Just charge a little lower, or charge a little higher.

There is really no specific times one has to use, providing the end result is still satisfactory. One of the aspects of being a home roaster is the ability to experiment with our machines, without worrying about customer complaints.