Adjusting Coffee Brightness Levels in a Hottop

[Coffeefreak]

Which bean temperature thermocouple are you using and do you recommend?

Where does one purchase it?

I do own and use (for cooking and baking) a Thermoworks digital thermometer with a long stainless steel probe, but its range is only from 32F to 392 F (probably not adequate for this purpose)
 

[GC7]

http://www.espressomyespresso.com/

check out "How to pages - #10 adding temperature monitoring to the hottop roaster"

I purchased my Omega probe here

http://theelectrostore.com/shopsite_sc/store/html/ktss-hh-omega-new.html

This is the datalogger I purchased but I got mine on ebay.

http://www.valuetesters.com/UEI-DT302-Apollo-2-Digital-Temperature-Logger.php

It monitors up to two probes at once and stores information for download to your computer for graphing.  There are others with one channel as well as cheaper digital thermometers that use a K-type thermocouple for real time monitoring without data storage.

ebay
http://cgi.ebay.com/UEi-APOLLO-II-DT302-Digital-Temp-Logger-NEW-Box-/140373454248?pt=LH_DefaultDomain_0&hash=item20aee8eda8

[Coffeefreak]

This morning, I drank the first of the roast that I did two days ago while attempting to follow your profile, but that got aborted because of my high line voltage. (Does that qualify for a "run-on-sentence" prize?)

Even though it was a little lighter that I desired, it definitely achieved more brightness (acidity.) :-)

The other point of interest is that you indirectly reminded me that I already own a dual probe Digital Thermometer that I purchased on ebay a while back. My intention was to adapt it to the FreshRoast chamber but I never found the correct location to run one of the K type probes.

My next roast will follow your altered instructions, and I look forward to Roasting Nirvana, or close.

Thanks again

[GC7]

Coffeefreak

I'm sitting on my porch roasting in 18* freezing weather and I look at my profile again and count the power bars and notice that the pre-heat after the beep from the machine at 167* on the hottop display is at SIX power (6) and not seven (7) .  That is part of your too high heat.  With your voltage I'd use 5 power at preheat stage and drop the beans when the hottop display is about 290*.

Hope this helps and sorry for the mistake previously.

[Coffeefreak]

18 degrees on your porch? It is 48 F on my porch right now, but I still opt to roast on the stove top under the hood.
This grizzly Texan likes "cool" weather, but I ain't no Polar Bear. 

P.S. Thanks for the temperature update info. I will be using it within the hour.

[GC7]

This has been a particularly tough winter in NY. 48* seems like a heat wave!

That's why I had to insulate the hottop

http://www.greencoffeebuyingclub.com/index.php?topic=10633.0

Let us know how your roast turns out.

[Coffeefreak]

Just completed my roast using (almost) your new parameters. I was a bit lazy and thought that I could jump back and forth from three different printouts. Next time, I shall edit and recopy the data on one sheet. It began to have 2nd crack when the Hottop readout said 413F, so I opted to eject then (this is for drip.) The beans look so perfect and smell so enticing that I had to restrain my urge to just scoop up a handful and chew them. 

As for the probe, the source where you obtained yours shows "out of stock." I sent them an email yesterday asking when they expect to have more. Several other dealers for that model probe list them for $10.00 more than where you got yours. Of course, many retailers can advertise a lo-ball price and then tack on high shipping charges.

One thought does give me cause for concern: If I drill holes to insert the probe, might that furnish an excuse for the manufacturer to invoke: "Machine altered or tampered with; Warranty no longer valid."

[GC7]

Seems lik ou are still a bit faster then I get here with my 118V (today)  >:(input so maybe tweek the power down a bit more or lower input temperature.  You can play with this depending on the bean.  Getting second crack at hottop display 413* is about right.

You can purchase a brand new bean cover chute for $10 fromm hottop so I don't see where any warranty would be affected in this situation.  You can always call Michael at Hottop and ask. He is great to deal with.

I shopped around to get the cheapest omega probe.  That is the place I found. Even with shipping it was cheaper than any other place I looked.

[GC7]

Seems like you are still a bit faster then I get here with my 118V (today)  >:(input so maybe tweek the power down a bit more or lower input temperature.  You can play with this depending on the bean.  Getting second crack at hottop display 413* is about right.

You can purchase a brand new bean cover chute for $10 fromm hottop so I don't see where any warranty would be affected in this situation.  You can always call Michael at Hottop and ask. He is great to deal with.

I shopped around to get the cheapest omega probe.  That is the place I found. Even with shipping it was cheaper than any other place I looked.

[Coffeefreak]

This morning, I did another roast trying to emulate your most recent instructions. It seemed that at a Heat Setting of 5 with the fan on the first notch, it was not moving closer to 1st crack as fast as it should.
The great part about this machine is that one can adjust all parameters "on the fly." I lengthened my initial time setting of 20 minutes, and upped the heat in increments until I could sense that 1st crack would come soon. It did, and I ejected just before 2nd crack and the dial read 413 F. The beans look pretty good.

As far as the Omega temperature probe is concerned, I attempted to purchase one at the place where you got yours. However, when I got to the cart it showed as "out of stock." I e-mailed them last week asking when and if they expected more Omega probes to be in stock. So far, they have yet to respond.
Hopefully, they will eventually do so which will spare me from "biting the bullet" and going to one of the more expensive dealers.

As of now, I have 27 roasts on the machine. What is your take on when and how often to change filters?

Thanks again

[GC7]

Now that you have a feel for the kinetics of your machine with its voltage and heat input you can begin to adjust the drop time for the beans and/or the input heat so that you get to first crack at 9-10 minutes and then slow the roast down nearing first crack by lowering heat and finishing within about 3 to 3.5 minutes after first crack is rolling. If you like you could also probably control your profiles pretty well this way with somewhat more beans (180-190 gm or so).

I wash my back filter in Calfiza detergent (for espresso machines) every 20 or so roasts and rotate among three filters.  THat detergent is great at removing coffee oils. They last a long time that way.

Good luck. If you order more filters from hottop you can also get another bean cover ($10) as a spare for drilling the thermocouple openings.  Drilling stainless is a PIA without a drill press.

[Coffeefreak]

I just received a reply  from the place where you purchased your Omega probe:

>Thank you for your inquiry. I have checked and unfortunately I don't expect that we will have these available again in the foreseeable future.

Sincerely,
Daniel

At 12:25 PM 1/22/2011 -0600, you wrote:
> I was going to order a Omega model KTSS-HH Type K Thermocouple probe from you, but it shows up on the shopping cart as out of stock. Do you know when you are expecting them back in stock?
>
> Thank you,

You got in at the right time. ;-) Eventually, I shall just dig deeper into my pocket and get one elsewhere.
But, my roasts are tasting so good lately with all of the assistance that I have received here that it does not seem too urgent.

[jimec3]

coffeefreak: . I got mine from mcm electronics. This one might work too http://tinyurl.com/6eqdem9. Once you get one try snaking it in through the front, its not as accurate as a fixed install but for me seeing how different it was inspired me to go for the gusto.

As for install I took the WHOLE thing apart and mounted mine on the back wall of the roasting chamber.  I used a stainless bolt that i drilled out on a press.  Then I pressed a stainless steel tube through it.  Then i bent the tube until it was center mass and put the thermo wire in till the tip just comes out of the tube.  PM me if interested and I could through a bolt/tube assembly together some night at work.

[John F]

I drop my beans depending on profile desired at environmental temperature of 320-350 degrees

 I get to first crack about 9 ½ to 10 minutes.

.. if I need to finish in 13-14 minutes and full city – For me City plus is bean temperature of 422-425*. Full city roasts are bean temperature 430-435* Second crack usually starts at bean temperature ~437-440*

Looking over your notes and comparing to my first HT roast I see these differences.

I dumped in at 275 with 22.50 on the clock.
Hit first around 12 min.
Terminated roast around 15 min temp 428.

I think simply waiting a min to dump in would have brought me in line with your profile.

I think next time I'm going to drop at a starting temp of 325 and see what happens.

[GC7]

John

Remember -

1- I use 170-180 gm of beans (usually 170 for brew and a bit more for espresso)

2- My quoted temperatures were from my omega bean temperature probe). Before I dump the beans into the drum I assume that I am mesuring the environmental temperature within the drum.  After adding beans I assume it is close to the bean surface temperature.

3- My HotTop is insulated as described in a thread on cold weathure roasting I started.  I am happy to provide some insulation material if you would like to try it.

edit - When I drop the beans into the drum at time 21' 30" the hottop display is usually more in the 285-300* range though I really don't look at it too much.  My experience with the bean temperature probe is that it tels me the hottop display temperature on the back wall of the roaster is relatively representitive of the rate of bean heating in the middle of the roast but varies A LOT early and late. Early on it reads much higher than the actual bean temperature and late in the roast it is significantly lower then the bean temperature.  Hope this helps.