Turbo Crazy (or dead horse)

[southernroaster]

I've roasted 6 batches on the Turbo Crazy roaster that I built. It's been very trial an error so far. I ruined a lb of beans the other day due to bad agitation. I had beans ranging from city to Vienna. It has been very hard to get a to a FC. One of my roast times went into 18 mniutes and still only came out to a City+. Basically I'm trying to learn roasting in an affordable way but I'm thinking maybe I should just sell my soul and purchase a roaster. My goal is to just make enough to cover the cost of roasting and maybe a little extra. The real reason I do this is for the coffee. And the fellowship that it brings. I love everything about it. But the Turbo Crazy is driving me insane. 22 minute roast times. Absolutely zero heat control (unless your're and electrical engineer and can add a variac to the thermostat). Thinking about just buying a Behmor 1600 plus. Ive looked at the reviews for it and other than the fact that it is still just a home roaster it seems pretty cool. Any thoughts?

 

[peterjschmidt]

I've roasted thousands of lbs. on my two SC-TO's (no variacs) and find them to utterly controllable, producing great coffees.

What do you mean 'by bad agitation' and how did that ruin your coffee? It sound like you're starting with too much coffee. What are your batch sizes?

 

[southernroaster]

I've roasted thousands of lbs. on my two SC-TO's (no variacs) and find them to utterly controllable, producing great coffees.

What do you mean 'by bad agitation' and how did that ruin your coffee? It sound like you're starting with too much coffee. What are your batch sizes?

Hey peterjschmidt, that was basically my frustration rant of the week mixed with anger from wasting good organic beans from Bali haha. I realize that this will take way more patience than I initially thought.

The only modification that I made to the stirring arms was clamping on some 1/2 inch long copper wire clamps facing upwards to act as somewhat of a stir paddle. And yes I went for the full pound to see if it how it would turn out and my insufficient agitation caused the beans to roast unevenly. Its a work in progress. I just thought that it would be a bit more "plug in and go". I have yet to do the stirring shaft mod though I do have copper cap on top of it, insulated with some aluminum foil. So far I have not seen any signs of melting. My heating issue is basically that it is hard to maintain the temperature when it finally does get there. Say for instance, I like to dry my beans for the first 3-4 minutes @ 300 degrees and then ramp up the temp to 360 until I hear first crack, maintain it til first crack is finished, then prolong the time before 2C. but it is hard to maintain the temps i need because the element shuts on and off and i end up stalling the roast.

A few questions I would love to have answers to:

How long is your average roast time for, lets say, a Full City roast
Are you basically at the heating element nob the whole time adjusting it
How do your beans compare (taste-wise) a regular roaster. (I saw from a previous post that you own a roaster as well)
Any tips would be greatlyyyy appreciated.
Thanks!

 

[peterjschmidt]

Try less coffee; I'll roast 12oz, or less. When you go too big on batch size, the perimeter will roast too quickly; the TO takes up air from the center, and after heating it, pushes it down the outside. There is no good way to agitate the beans so that they move from center to perimeter and back.

I treat the knob and t-stat as the on-off switch it actually is. Greens go in, knob is at 500. Beans hit 280 (as measured by a thermocouple), knob is turned low enough that the heating element light goes off. Beans coast up to 300, and after a 1.5min. drying time, knob is turned back to 500. Beans hit 345, knob is again turned below that temp so the beans can coast for 1.5min up to perhaps 355 - that's the sugar caramelization zone. After 1.5min, knob is turned back to 500, ramping to 1C.

You simply need to use less beans, and learn how to predict coasting time and how much time is needed for the element to come back on and heat up so that temps begin increasing again. Once you have that down, it gets to be a 'zen' kind of a thing, and you'll be able to roast without constantly moderating the knob. I'd suggest doing the shaft mod only if it fails. And then, the easiest/cheapest/bestest mod is to drill into the body of the shaft and insert a hanger bolt.

The SC/TO, when mastered, will produce a roast that is only slightly inferior to a commercial machine.

Good luck! Don't give up; it's a very rewarding way to roast once you get the knack of it.

 

[southernroaster]

Thanks Peter, I've ordered a scale. These are such newbie issues but I have to get through them somehow. Thank you very much for your help.

 

[peterjschmidt]

I understand.

Every stirring arm modification will have its sweet-spot. The stock arms aren't bad, right around 8oz. IIRC. If you go smaller you get the "angel wings" effect where you just have two clumps of beans being pushed ahead of the arms. And if you go too large in batch size, the stock arms will just glide underneath without disturbing the beans mass much. That's why people like to add barrier strips etc. to the arms. But that just moves your sweet-spot up a few ounces and to get them to agitate in their sweet-spot can mean getting the batch so large that you don't get evenness from the center out to the perimeter.

Keep at it, and remember, even your beginning roasts are better than 95% of what you can buy.