Hottop Profiles / Q&A / Tips & Tricks

[rgrosz78]

The geeky scientist in me is tempted by the tc4c as well, but I've performed other less expensive mods (look up RAF on Homeroasters.org) that are giving me a very satisfying roasting experience.  The tc4c would allow more consistency for sure, but I'm beginning to appreciate the art form of roasting more and more.  Either way, the HotTop is a blast to use.  Now if it just could roast larger batches.......  Down the rabbit hole I go.

I simply LOVE the TC4C on my Hottop - best upgrade ever! But I am sorely tempted by other roaster choices with bigger capacity (aka Huky).

I get my best results on the Hottop with only 195g. I normally do 4 roasts each week, which takes about 3 hours (including cool-down). Sometimes it is hard to carve out that much time on a Saturday.

[rgrosz78]

I bought metal filter that fits perfectly on HT:
http://www.suntekstore.com/goods-10008829-aluminum_filter_dust_guard_12cm_120mm_for_pc_case_fan.html

First I used only the metal filter, but resistance is very low, and roasting was even dependent on outside weather as my HT is connected to vented hood. 

Then I decided to put back original black cloth, and resulting filter gives very predictable results.  Soaking in cafitza returns filter 100% efficiency.  I will see how long the cloth will last.

I finally made this Hottop mod in December, and I am very happy with the results. I did not detect any change in the roast process, so I no need to change any profiles.

It is very easy to clean the metal filter material by soaking. I no longer have to worry about damaging the paper - or when to replace the paper filter material. As Miroslav said, "very predictable results", which makes me a happy camper.

[GC7]

The geeky scientist in me is tempted by the tc4c as well, but I've performed other less expensive mods (look up RAF on Homeroasters.org) that are giving me a very satisfying roasting experience.  The tc4c would allow more consistency for sure, but I'm beginning to appreciate the art form of roasting more and more.  Either way, the HotTop is a blast to use.  Now if it just could roast larger batches.......  Down the rabbit hole I go.

I simply LOVE the TC4C on my Hottop - best upgrade ever! But I am sorely tempted by other roaster choices with bigger capacity (aka Huky).

I get my best results on the Hottop with only 195g. I normally do 4 roasts each week, which takes about 3 hours (including cool-down). Sometimes it is hard to carve out that much time on a Saturday.

Like you I had been roasting using batches from 175 to 195 gm to get my best results. I bout a variac so that I could maintain adequate voltage year round and it has made all the difference. At full power and 118-119 volts (for reference) I get equally good roasts of 227 gm. The variac is a great tool that I would not be without any longer. Perhaps my ET's are a touch higher but I've never seen tipped or scorched beans. Just a thought for you to get more output.

[rgrosz78]

Like you I had been roasting using batches from 175 to 195 gm to get my best results. I bout a variac so that I could maintain adequate voltage year round and it has made all the difference. At full power and 118-119 volts (for reference) I get equally good roasts of 227 gm. The variac is a great tool that I would not be without any longer. Perhaps my ET's are a touch higher but I've never seen tipped or scorched beans. Just a thought for you to get more output.

+1
I have been using a variac with my Hottop from the beginning (back in 2012). It was necessary in the summer time, due to heavy power draw of our air conditioners.

My recent experiments with roasting greater loads did not make me happy - it just extends the roast "a bit too far". I'm probably a bit too picky, but to me the coffee is not quite as good:
230g took 11:40 for 1st crack, 14:10 total roast time
200g took 10:20 for 1st crack, 12:50 total roast time

[ptrmorton]

230g took 11:40 for 1st crack, 14:10 total roast time
200g took 10:20 for 1st crack, 12:50 total roast time

Curious, how hot is your charging temp and how long for your BT to get up to 300F or 149C?  My development time is very similar for 230g, but I reach 1st C right around 10 minutes.  I do use a variac and have insulated my roaster among other mods.  Thanks in advance.

[GC7]

I dump the beans between 305 and 320 degrees (on the hotspot panel- about 350 or so on the ET thermocouple) depending on bean hardness. It takes 5-5 1/2 minutes to get to 300* bean temperature and first crack between 9 to 10 minutes with 227 gm beans

[ptrmorton]

Very similar.  Thanks.

[GC7]

Turn temperatures on my bean temp probe are generally 175-185* and I keep the voltage at 118-119 when on full power. It is a very reproducible.

[ptrmorton]

Turn temperatures on my bean temp probe are generally 175-185* and I keep the voltage at 118-119 when on full power. It is a very reproducible.

Interesting.  My turn temp is slightly lower (165-175), but we end up in the same spot after 5 minutes.  Lots of factors to account for that.  Thanks for the confirmation and information.

[GC7]

My roaster is insulated. There is a whole thread on it from back in about 2010 or so. That could account for the difference.  As you stated there could be lots of factors affecting roast times.

[ptrmorton]

Mine is also insulated, but I've reversed the air flow.  Actually, I'm impressed how similar they are.  Thanks again for the info.  Always looking for more knowledge on roasting!  I love it.

[GC7]

I had to replace the heating element last year. Perhaps that's part of the small differences we see in roast times? My top filter has insulation in it as well. I find our results remarkably similar and that is nice to see. The reverse flow interests me. I never thought the hottop utilized convection as well as it could-

[rgrosz78]

Curious, how hot is your charging temp and how long for your BT to get up to 300F or 149C?  My development time is very similar for 230g, but I reach 1st C right around 10 minutes.  I do use a variac and have insulated my roaster among other mods.  Thanks in advance.

I too have insulated my roaster, and replaced the heating element in September 2015. I use a wide range of charge temps, anywhere from 225F up to 425F. The time to first crack varies widely for different coffees that I roast.

For this particular bean I charged at 275F:
230g load - hit 300 at 6:30, took 11:40 for 1st crack, 14:10 total roast time
200g load - hit 300 at 5:50, took 10:20 for 1st crack, 12:50 total roast time

[ptrmorton]

I too have insulated my roaster, and replaced the heating element in September 2015. I use a wide range of charge temps, anywhere from 225F up to 425F. The time to first crack varies widely for different coffees that I roast.

For this particular bean I charged at 275F:
230g load - hit 300 at 6:30, took 11:40 for 1st crack, 14:10 total roast time
200g load - hit 300 at 5:50, took 10:20 for 1st crack, 12:50 total roast time

Thanks.  Almost the entire difference in our roasting time is at <300F.  Probably due in part to my higher charging temp.  I appreciate the sharing as I'm always looking to improve my roasts.  I'll try cutting back on the batch size and lower my charge temp and see what happens, but my previous experience is that profile changes below 300 F aren't as crucial. as long as they are not too extreme.  Of course, my taste buds could be damaged from all those years of bad coffee before I discovered the joys of roasting!

[aletab]

I've had my hottop for about a month and run 3-5 batches each weekend. So I am starting to get a handle on it and can get good roasts from it at this point. But one thing I still do not understand is the fan. I am using the standard paper filter.

I ran some experiments to get a feel for how quickly it responds to changes in heater (slow!) and fan settings. What is weird is that I see no difference between 10% fan and 100% fan. For example, if half way through a roast if I drop the power to 0% and watch deltaBT drop off – it drops off at the same rate with the fan at 10% or 100%. Or maybe it is subtly different but not enough that it is going to make a difference. I was hoping that I could get it to react faster by using the fan but that doesn’t seem to do what I expect.

Now I can see that part of the function of the fan is to clear smoke but shouldn’t it also draw outside air in and cool the environmental temp faster at a higher setting? Does this sound weird? Normal? Am I missing something?

I like this roaster a lot and using Artisan with alarm files is cool but I am mystified about the fan.