roasting time paradox

[shimrah]

Hi,

I have a FreshRoast Plus 8 (I think the "8" refers to the switch, which is a max 8 minute timer + cool-down) coffee roaster, and something is puzzling me.

The roaster is similar to the popcorn maker (Hamilton Beach) that I used to use to roast coffee. When I was roasting with the popper, I kept reading about how the ideal way to roast in the popper is to keep the temperature LOW, resulting in a roast that takes somewhere between 6 and 8 minutes (generally 4 or so minutes to first crack).

Then I get this roaster that pops (er, I mean roasts) coffee in about 3 minutes. At first this seemed like a problem, but I'm actually finding that the coffee is tasting a lot better (which, in the end, is the true measure). Can anyone comment on this?

I'm wondering if the beans were somehow getting "dried out" in the popper because of the long roast time. (Maybe this only affects air-roasted, as the aair would cause more evaporation of volatiles?)

Thoughts?

Cheers,
Shim

 

[RoastingGuy]

Relationship with the power and coffee quantity

Everything is in relationship between power factors, type of roasting and weight of coffee. If your roaster doesn’t give you a good developing and if you got black spot on beans you can decrease or increase the coffee quantity and try again. It’s de base of the roasting principle.

Best Regard,

 

[topher]

ummm...black spots can also mean you are going to fast...using too much heat and not enough time...

 

[RoastingGuy]

Relationship with the power and coffee quantity

Sure, this also a usable parameter. Read this.

Everything in roasting is in relationship between (power factors), (type of roasting : contact, convection, radiation, etch…), (heat transfer efficiency percentage), the volume of the coffee confine by the weight of coffee. If your roaster doesn’t give you a good developing and if you got black spot on beans, or if the taste is bad you can decrease or increase the coffee quantity, also the heat, and try again. It’s de base of principle. Therefore, if you got good green coffee, faster you roast it more you keep the good flavor of it. If you got bad green coffee more you keep the bad taste of it. If your roaster gets good heat transfer faster you can roast. If the heat transfer is poor you need to roast slower or you get black spot on the bean. A good roaster is roaster with minimum 80% heat transfer capability. But all other roasters are not so bad. To make a good roast with bad roaster you just need to reduce power and coffee quantity on it, to make (power factor and transfer factor relationship) that it.

Try that, and give me new on.

Excuse my English.


Best Regard,

 

[rollman]

Hey Roasting Guy

How do you tell when a roaster is running at 80%?
or at 80% or more heat transfer capability?
How fast does a good fast roaster roast?
Radiation?

 

[RoastingGuy]

When roaster is 80% or more you can consider a good roaster but, no name for that, is efficiency. Heat transfer % capability is the capability of the heat source to go easily inside de beans.
It existing 3 types of roasting methods.

First: Contact. If you use 100% contact heat (heated metal to transfer heat to the coffee bean) it’s named contact roasting method.

Second: Convection. If you use hot air in movement, it’s called convection roasting.

Third: Radian. If you use radian source, it’s called radiation roasting.

The best roaster is the roaster able to combine that 3 heat’s method’s together and where you able to adjust the percentage of each like you want, to roast the coffee as you wish.

How to calculate the efficiency of heat transfer: Take the energy inlet power and subtract to outlet.
That’s it.

 

[rollman]

Not bad

Hey fellow you are sound!

I have worked on a roaster or so and If you can
get the lingo down I understand mucho of what you are talking about.

On transferiing heat to Roasting coffee I agree you have covered the big three! Amount of heat, transfering heat by air flow, and that drum cracking direct heat (the no-no heat) You need some but only to get the drum material to a temperture slightly above the air temperture no more.

Does the quality of the flame ( leanness or richness) make a difference
on how the coffee tastes?
What effect will this have on the Flavor of the coffee if the roast times are the same?
Can the flame quality effect the amount of time that the roast will take to finish even it the roaster is at the same temperture and air flow?

For bonus points

How effective is a heat exchanger on a coffee roaster? like when you are going to use fuel oil for the heat source but do not want to smell up the coffee?

If you knock this out I'm moving you to the A team.

I could not have answered them without some engineering help from the staff recently.

I will send you some customers

 

[rollman]

For the record

Roasterguy answered all my questions by a private posting.
He answered them all and even got extra points on the final question!
I have never met the guy but hats off!

Culligan might be in trouble!

Hey RoasterGuy!!!

or

My Machine is a well. you know?? a real good one..... one of type

Roaster Guy will work on!!!