Gas Dip Success - Page 3

#21: Post by **GC7** » November 30th, 2020, 12:58 pm

bradm wrote: So yes the second rule is violated, but no crash.

It certainly looks good and appears you could use that profile to go dark if you needed.

I also see the bullet fan induced little dip at F3 start that give me fits roasting in the garage.

November 30th, 2020, 2:16 pm

Glad to see this worked on your Bullet. I believe Rao's rules for heat changes were devised on gas roasters. When I used an electric roaster, there was often a lag associated with a power change, so perhaps that's why your power dip worked even though it didn't precisely follow Rao's recommendations?

#23: Post by **GC7** » November 30th, 2020, 2:53 pm

Brewzologist wrote:Glad to see this worked on your Bullet. I believe Rao's rules for heat changes were devised on gas roasters. When I used an electric roaster, there was always a lag associated with a power change, so perhaps that's why your power dip worked even though it didn't precisely follow Rao's recommendations?

Steve - One of the nice features of the Bullet is induction heating that does not have the lag of a heating coil used in other electric roasters. Heat changes are pretty much instantaneous and as fast as gas from what I understand. The IBTS measurements of bean temperature also don't have the lag of a thermocouple, however, they have not found a good way to use this for the ROR curves as yet. That part I don't understand. So, the bullet ROR uses its thermocouple measurements and will be lagging as with any roaster using BT thermocouple to measure bean temperature.

November 30th, 2020, 10:14 pm

We talk about timing the gas dip but shouldn't the dip be executed at a temperature instead of a time?

Like I look at the crash, go back 40 seconds and look at the temp. Then in the next roast I dip at that temp. At least that's what Scott said to do. I am only pointing this out because it was not obvious to me until I was told to do it that way.

#25: Post by **dhdhk** » December 1st, 2020, 2:48 am

Brewzologist wrote:I have experimented with various Gas Dip techniques in the past with limited success. Meanwhile, I have this Sumatran I take to a medium roast for blending purposes, and it has defied every technique I've tried to get a really good result. As soon as I get beyond light roast territory it gets hard to control. When I got my copy of Rao's CRBP book I noticed he included a more detailed description of performing the Gas Dip. Today I tried it for the first time on that darned Sumatran and whaddya know; it worked like a charm. Thanks Scott! Just thought I'd pass on this learning from CRBP for anyone who may need it.

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Nice one! Ive been struggling with the Sulawesi Toraja that has a crazy flick and crash (seems to be a thing with Indonesians) so I do I dip and then spike to counteract the crash after FC. I roasted this one a bit darker to get some of that old-school espresso taste, with the chocolate, caramel flavors.

I also blend indonesians with brazils and africans to get a fruity, chocolatey espresso.

December 1st, 2020, 9:12 am

LBIespresso wrote:We talk about timing the gas dip but shouldn't the dip be executed at a temperature instead of a time?

Like I look at the crash, go back 40 seconds and look at the temp. Then in the next roast I dip at that temp. At least that's what Scott said to do. I am only pointing this out because it was not obvious to me until I was told to do it that way.

Agree. This was the big "ah-hah" moment I got from reading CRBP that I did not know from my previous attempts at using the gas dip. Highly recommend the book for this and other info.

December 1st, 2020, 9:24 am

dhdhk wrote:Nice one! Ive been struggling with the Sulawesi Toraja that has a crazy flick and crash (seems to be a thing with Indonesians) so I do I dip and then spike to counteract the crash after FC. I roasted this one a bit darker to get some of that old-school espresso taste, with the chocolate, caramel flavors.

I also blend indonesians with brazils and africans to get a fruity, chocolatey espresso.
image

I have used a similar approach with my challenging beans. The technique described in CRBP may help you to refine your results even more.