New HotTop for the homeroasters

[cannonfodder]

I was looking around the Internet for no good reason today when I went over to the HotTop web page to look around. Surprise! Hottop has a fully programmable unit in the works, the KN-8828P. You can finally temperature profile your roasts! That was the one big thing I missed when I went from my home made roaster to the HotTop.

The control unit and display will be available as a kit so current owners can retrofit their existing machine.

[KarlSchneider]

Dave,

This does look like a great advancement on an already good roaster. I find myself wondering what the learning curve will be with all those variables.

Ultimately would there not be a profile for each green bean?

KS

[cannonfodder]

Each green would have different profile. There is the factory set profile so if you do not want to explore the roast profile space, you can still set it and go.

Professional roasters spend a lot of time and effort temperature mapping a particular origin to get the most out of the bean. I do not spend the same kind of time and resources profiling a particular green, but I do make basic observations as to the beans cup vs roasting parameters. Then adjust the profile to the bean. I believe they listed 8 programmable profiles plus the factory default. I rarely have more than 10 different origins in my stash.

There is still no pricing for the new machine or the upgrade package to retrofit your existing unit. Hopefully it will be reasonable and I can upgrade my control unit. That should make the machine just about perfect for the novice or advanced home roaster.

[Marshall]

What, exactly, will it measure?

[cannonfodder]

Since the new unit appears to be a direct plug and go upgrade, I am assuming that it still measures drum air temperature, not bean mass temperature like the commercial machines. While not ideal, it would still give you a measure of control that is currently absent.

I had my machine apart last week for a good cleaning and was poking around looking at ways of putting a thermocouple in the drum to get bean temperature. You could run a TC in through the back wall and into the very back of the drum, suspended just above the drum surface, so it would be in the bean mass. The problem is that you could not get it very far into the roasting beans because of the rear drum support. I was looking at the drum wondering if I could get the welds that hold that rear cross support to break loose but they look like they were welded very tight. If you could loosen it and slide it an inch further into the drum and re-weld it, you could get a TC placed nicely in the bean mass.

If the Hottop used a TC, you could disconnect the existing drum air sensor and wire in the bean mass TC so the machine. One of these days I may get bored and try it out. Worst case I break the drum and have to order a replacement.

[mrgnomer]

I'm looking seriously this year into upgrading from an iRoast 2 to a good drum roaster. I don't have a gas BBQ and need an indoor roaster or the RK drum would be a gread choice from what's being said about it.

With the interchangable control panel upgrade promise the Hottop analog looks like the best investment to me. I might hang on for a bit if the ugrade Hottop is coming out soon. Any idea when it's going on the market?

[cannonfodder]

Limited availability in a week or two with general availability in another 4-6 weeks. I have not looked at their web page lately. I was told (by Hottop USA) that an update was going up soon a couple of weeks ago.

[mrgnomer]

Thanks, Cannonfodder.

With a month or two more of saving I hope to afford the upgrade. Cool.

[Dogshot]

What role does the fan play in a drum roaster?

The reason I ask is that I understand that the upgrades are to cost in the area of about $600. This will give the user 8 points during the roast cycle to change temperature and fan parameters. I would rather have total manual control, and a variac (for half the cost of the assumed upgrade cost) attached to the analog model would allow manual control over the heat, wouldn't it? Other than cost, there must be a drawback, otherwise it would be a more popular combination. So, is it the fan?

Mark

[Abe Carmeli]

What role does the fan play in a drum roaster?

The reason I ask is that I understand that the upgrades are to cost in the area of about $600. This will give the user 8 points during the roast cycle to change temperature and fan parameters. I would rather have total manual control, and a variac (for half the cost of the assumed upgrade cost) attached to the analog model would allow manual control over the heat, wouldn't it? Other than cost, there must be a drawback, otherwise it would be a more popular combination. So, is it the fan?

Mark

The fan helps distribute heat in the drum & directs smoke out of the drum. The hottop fans the air from the drum out. A Variac will give you marginal control on roast profile with the current version of the HotTop. If you try to extend the space between first and second crack for instance by lowering the voltage, you will most likely fail to reach 2nd crack altogether. I tried it, it is very hard to work with since the hotTop has its own roast profile based on 110-120 current.

As to an industrial drum roaster, there you can control the fresh air that flows into the drum. Fresh air introduces more oxygen, and that plays an important role in roasting. Roasters will often deprive the beans of fresh air or infuse fresh air in various stages of the roast to affect the profile. If the new upgrade to the hottop introduces that option as an enhancement I'll be mighty surprised.

[cafeIKE]

If the new HotTop uses the same back of chamber sensor, then the profiles will be based on an offset, rather than the bean mass temp. The current temperatres read vary as much as 70F from the bean mass probe and 170F from the environmental temperature. If the sensor is insulated from the chamber wall, it might be more accurate.

The user will still need a bean mass temperature probe to verify the set profile is actually impressed on the beans.
Randy Glass has a page on inserting a TC in the bean mass that works quite well.
http://home.surewest.net/frcn/Coffee/HowToHottopTemp.html

Split wiring the HotTop gives 100% control of the roast profile.
http://www.ielogical.com/coffee/HTManualMods.rtf has rudimentary instructions for the adventurous.

I added an environmental temperature probe for information on what happens with fan control. I also added an external power supply to increase the volume of air moved by about 50%. When used in conjunction with the variac to reduce input power, it can have a useful effect. The HotTop holds a lot of heat and there is not much opening for air flow. Open chaffe tray about 1/8" after 1st to increase air flow.

[Abe Carmeli]

These are great instructions Ian. Add a PID controller to that setup and you may be able to have programmable roast profiles that will control both the heat element and fan.

[cafeIKE]

These are great instructions Ian. Add a PID controller to that setup and you may be able to have programmable roast profiles that will control both the heat element and fan.

Too much like my day job.

Being a Luddite at heart, I like the hands on manual approach and the occasional serendiptous surprise that occurs when I bollix the roast.

[Theodore]

If the new HotTop uses the same back of chamber sensor, then the profiles will be based on an offset, rather than the bean mass temp. The current temperatres read vary as much as 70F from the bean mass probe and 170F from the environmental temperature. If the sensor is insulated from the chamber wall, it might be more accurate.

The user will still need a bean mass temperature probe to verify the set profile is actually impressed on the beans.
Randy Glass has a page on inserting a TC in the bean mass that works quite well.
http://home.surewest.net/frcn/Coffee/HowToHottopTemp.html

Split wiring the HotTop gives 100% control of the roast profile.
http://www.ielogical.com/coffee/HTManualMods.rtf has rudimentary instructions for the adventurous.

I added an environmental temperature probe for information on what happens with fan control. I also added an external power supply to increase the volume of air moved by about 50%. When used in conjunction with the variac to reduce input power, it can have a useful effect. The HotTop holds a lot of heat and there is not much opening for air flow. Open chaffe tray about 1/8" after 1st to increase air flow.

Hi.
Those modifications convert the machine to a better manual one, or they go into the machine"s program, changing the air temp measures to bean mass measure.
Regards,
Theodore.

[cannonfodder]

What role does the fan play in a drum roaster?

The reason I ask is that I understand that the upgrades are to cost in the area of about $600.

$600 sounds like the price for the entire machine, and relatively reasonable. The Hottop digital is $600-645. Hopefully the P control pad will be in the $80-100 range.

[Paolo]

The reply that I got from Hottop USA about the cost of the upgrade was that the upgrade itself would be between $500-$700!
That puts me out. I will stick to the Hottop as is.

Regards,
Paolo.

[harris]

$500-$700 for the upgrade? (choke, choke)

......... and here I thought I could buy an analog and upgrade.

Time to look into PID'n something.

[miKe mcKoffee]

For much less (projected) cost with highly likely equal or better control though not as flashy as new controller manual HotTop plus PID. And throw in a fixed voltage boost to the heater circuit for even greater profile and batch size flexibility. Scott actually tested 1# batch without voltage boost, required heater full on entire 19 minutes for the roast.

Here's a pic' of Scott's FrankenTop unveiled about a year ago on SM List:

[Theodore]

$500-$700 for the upgrade? (choke, choke)

......... and here I thought I could buy an analog and upgrade.

Time to look into PID'n something.

I asked Hottop about the new model, and they asked me the following.

" Dear Athens,
The completed machine about us $1200.00, the upgrade is about us $600.00 for 230v.
It will be available end of this month.
shelly."
Theodore.

[cannonfodder]

That is crazy. They will probably not sell many at that price, guess I will not be upgrading.