SC/TO Profiles / Q&A / Tips & Tricks

[headchange4u]

 

This is the thread to post any questions, tips, or ticks for improving roasts using the Stir Crazy/ Convection Oven roasters. I also thought it would be cool to post the roasting profiles that you use when roasting with a SC/TO setup.

GCBC SC/TO Threads:

John F's SC/TO Thread
SC/CO Roaster Information
Turbo Oven Life Expectancy
Stir Crazy Power Cord
SC/CO Thermometer Options
SC/CO Mods/Construction

Other SC/TO Links:

Constructing a SC/TO 1
Constructing a SC/TO 2
peter's Nice Roaster Setup
Stir-Crazy vs. Salton UFO Popper (CoffeeGeek)
GCC SC/TO Forum
Sweet Maria's Homeroast on the SC/TO
Buy a Pre-made SC/TO Roaster

If you have anymore links, post them and I will add them to this first post.


I'll get us started as I have a couple of questions.

Someone recently mentioned that they used different sized spacer rings for roasting different types of coffees. Is this a common practice? How to you choose the spacer ring height for each coffee? Trial and error?

A friend of mine also gave me Galloping Gourmet clone convection oven top. He had broke the bottom casserole dish. The temperature dial is messed up. The heating element will come on but only when physically hold the knob to it's highest position with some pressure. If you take you finger off the knob the blower continues to run but the heating element kicks off. What I would like to do is bypass the temp dial and add a toggle switch that would allow me to manually turn the heating element on and off. Can anyone give me some advice on where to install the switch? Could I just disconnect the wiring going to the dial and then connect that wiring to a toggle switch? I can, and may have to, open the unit up to take some pics.

[headchange4u]

Here a nice looking profile that peter posted in another thread:

I use a SC/CO. Bottom heat rarely if ever used.
Beans go in the roaster.  Heat is on.
Beans hit 300?, kept there for 3-4 min.k, beans are tan before going further.
Heat is back on, beans hit 350?, kept there or inching up for 2-3 min to 360?.
Heat is back on 'til 1st, beans go through 1st lazily to keep them from taking on heat and racing right from 1st to 2nd.
1st ends, temps hold or sloooowly rise.
If FC or beyond is the target, heat goes back on.

That's my profile.  I haven't found the need to vary it much for various beans.  When I'm roasting samples for the Cabal to cup I try to be careful and keep the profile consistent to remove as many variables as I can, so posting a profile for each sample would be redundant.  So look at that profile, understand that it happens sorta kinda like that, and ask yourself 'even if it was exactly that profile, is that the type of information that will help me?'  With your roaster, and ambient temps, and all, it may be a starting point.

My basic profile is to add beans and set the temp to ~400. At the end of about 4 minutes the temp should be at about 250-260*F. After 4 minutes I crank the temp to the max, ramping the temp up to 360*F, usually at about the 7 minute mark. When temps hit 360* I cut the heat back and let the beans roast at 360-370* for about 3 minutes and then kick the heat back on high. This usually puts first crack at about 11:30 - 12 minutes. If I am trying for a light roast I will let the heat continue to rise and after the temp hits 415-425* I cut the heat back and let the beans finish the last minute or so at a lower temp, usually 40-410*.

[kuban111]

Thanks for posting this,


The weather is on the warm side here in New Jersey..think I'm going to fire up my TO and roast some coffee....need to give the Behmor a rest anyway.



Thanks.

[peter]

Shaft Mod

When the threads melt, or get old and brittle and snap off, here's a cheap and easy fix that maintains the proper alignment of the motor/shaft/stirring arms.

Most good hardware stores and Home Depot-type places, in their specialty hardware section carry something known as a hanger bolt.  It's a small rod with threads on both ends; one end has wood screws, the other machine screw threads.  Find the hanger bolt that has 1/4-20 machine screw threads on the one end.  Grind down the plastic threads on the SC shaft until flush.  Drill a hole down the center of the shaft, just smaller than the wood screw threads on the hanger bolt, just slightly deeper than those threads are long.  Screw the hanger bolt into the shaft, so that only 1/2" of the machine screw threads are protruding.

You'll now have the original shaft with new metal threads, rendering it nearly indestructible.

[headchange4u]

Cool mod peter. I have a stock SC sitting in a closet at home. I may try this method.

[SusanJoM]

Question about my UFO/TO project.

I spent a drizzly morning combing through wet and nasty bits at the salvage yard and the narrowest strip of still bendable aluminum I could find was 3".  Has anyone used this for a spacer?  Will it keep the roaster from getting hot enough? 

I see that Peter uses 1". 
Tex recommended 2".
Springform pans are usually 3".

What say you?
Should I pursue finding a narrower bit?

Susan

[Tex]

...at the salvage yard and the narrowest strip of still bendable aluminum I could find was 3"...

Find the nearest Ace Hardware store, Susan. They carry all sort of metal goodies - pick up a 1/16" x 2" x 4' piece of aluminum bar stock (~$6). They'll also have the 6 mm wing-nut you'll need, plus the nuts & bolts for holding the chaff ejector open (I use a short spring to keep the chute open - it slips over the screw).

[SusanJoM]

...at the salvage yard and the narrowest strip of still bendable aluminum I could find was 3"...

Find the nearest Ace Hardware store, Susan. They carry all sort of metal goodies - pick up a 1/16" x 2" x 4' piece of aluminum bar stock (~$6). They'll also have the 6 mm wing-nut you'll need, plus the nuts & bolts for holding the chaff ejector open (I use a short spring to keep the chute open - it slips over the screw).

Okay, okay, okay.....
back out into the rain....
Yucko...

Susan

[peter]

Aluminum yardsticks are a good (inexpensive) way to go.

I strongly suggest mounting the spacer to your SC so that the ends overlap, but spring shut.  That way you get the choice of having it open to let chaff and heat out, but also can close it to keep heat in.  Just make sure you check the direction of the TO circulation so that the spacer/chaff ejector opens the right way to scoop the chaff out when open.

[SusanJoM]

Aluminum yardsticks are a good (inexpensive) way to go.

which must mean that 36" is long enough to make the circumference ....

hmmmmm....
okay then....

[barko78]

anyone have experience roasting 4-6oz in the SC/TO set up?  I'm considering building one to use as a sample roaster and most likely would use 4-8oz batches.  Also, one of the links on the original post show the heater in the SC disconnected.  I'm thinking to keep the heater connected and maybe put it on a dimmer or switch in case additional heat is needed, especially with high grown centrals.  Does the TO provide enough heat to get the beans on a nice ramp on it's own??  Thanks everyone.

Ben

[peter]

With the right arms, and the bottom heat switched off, you can do a half ounce if you want.  Because of how my thermo-probe works, it makes it harder to measure temps with small roasts, but the set-up is flexible enough to do whatever you want.

[ButtWhiskers]

The biggest problem when going to a really small batch is proper agitation.  As peter said, with the right arms you can direct the beans toward the center which allows for similar bean-to-bean contact and agitation that you get when roasting more.  Without any mods, tipping is likely.   I also find that I have to start out at lower oven power, and wait about 6 minutes before ramping up, on very small batches (2 oz).

[barko78]

Thanks for the suggestions Peter and BW.

I built a simple control box type thingy with some spare electrical parts I had laying around.  I still have to mod the arms of the turbo crazy (today) and figure out a thermocouple placement.  The turbo crazy was ordered from the manufacturer and hopefully will be here this week.  I'll post pics/comments later today.

Anyone try to bring the thermocouple up from the bottom of the stir crazy?  I'm thinking of bringing it up from below about an inch from the center spindle and having it 90 keeping it shallow.  The stir arms could be bent up slightly (notched) at that location to pass over the thermocouple.  Just thinking outloud.

[peter]

If your temp probe is permanently mounted in the SC, it will be a pain to dump.