Best method for roasting? Propane, electric, natural gas?

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
moreshots

#1: Post by moreshots » Aug 19, 2011, 9:17 am

Looking for your input and suggestion on what is the better method for roasting also pro's // cons if you have any

Infrared ?
Propane ?
Natural Gas?
Electric?

Thanks

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Randy G.

#2: Post by Randy G. » Aug 19, 2011, 9:33 am

You left out Wood, Solar, Geothermal, Nuclear, and Chemical.

Infrared is not a fuel source. It is a radient energy (radiation); one of the three methods of transferring heat in a roaster: radiation, conduction, and convection.

Thermal energy is thermal energy. Any of those you listed, and a few of the above, are all effective or can be applied poorly. The "con" of electrical is that is responds slowly to changes and is generally used for smaller batches (relatively speaking). The choice in gases would be decided by cost, availability, and portability...
all the above IMO.
Espresso! My Espresso!
http://www.EspressoMyEspresso.com

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endlesscycles

#3: Post by endlesscycles » Aug 19, 2011, 9:50 am

I would say electric is the most versatile, safest, and could be the cheapest via solar. It's also easy to control, and emits no reaction gasses of its own. It's reaction time is a function of element thickness and airflow. It could be the fastest to respond under good conditions.
-Marshall Hance
Asheville, NC

moreshots

#4: Post by moreshots » Aug 19, 2011, 10:18 am

I work in the Nuclear indusrty and already have a small reactor !!!LOL!!!!

So for infrared you can use electric or Propane?
Randy G. wrote:You left out Wood, Solar, Geothermal, Nuclear, and Chemical.

Infrared is not a fuel source. It is a radient energy (radiation); one of the three methods of transferring heat in a roaster: radiation, conduction, and convection.

Thermal energy is thermal energy. Any of those you listed, and a few of the above, are all effective or can be applied poorly. The "con" of electrical is that is responds slowly to changes and is generally used for smaller batches (relatively speaking). The choice in gases would be decided by cost, availability, and portability...
all the above IMO.

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another_jim
Team HB

#5: Post by another_jim » Aug 19, 2011, 10:30 am

A really small gas burner has 9000 BTU/h. That is about 2.5 KW, which is a a substantial electric heating element. In other words, for small quantities of coffee, a half pound or less, in domestic settings, electricity is convenient. For anything more, or any time use cost is a factor, use gas or propane.
Jim Schulman

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Arpi

#6: Post by Arpi » Aug 19, 2011, 10:48 am

moreshots wrote:So for infrared you can use electric or Propane?
Yes. Infrared is "light" emitted by hot bodies (your body is emitting right now 'light'). It is made up of the same stuff as radio waves or visible light (electromagnetic radiation). Usually people confuse long wave and short wave infrared. Short wave infrared behaves very similar to visible light so like in security cameras, you use a source and it bounces off from people. Long wave infrared is absorbed by bodies depending on their outer layer reflectivity to this wavelength (beans would absorbed it very well). For example, glass reflects long wave infrared but passes through visible light.

So if you heat up a piece of iron (or any other object), then it emits more long wave radiation (the type you want for roasting beans) which would be absorbed by the beans. Whether the heat source is electricity or gas, it does not matter in terms of emitting radiation. The only thing that matters is its temperature and its outer surface coat (emissivity).

Propane has the advantage that it heats up the air a lot, but that is not radiation. It is convection (a form of conduction).

Cheers

moreshots

#7: Post by moreshots » Aug 19, 2011, 12:41 pm

Arpi,
Thank you ,
I will be using propane for this build

I was looking at an Infrared burner for the propane but hard to find a small one
Thanks Bill

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endlesscycles

#8: Post by endlesscycles » Aug 19, 2011, 2:25 pm

I use 40lbs of propane/month to roast about 900lbs. My cost is $40, or about $0.044/lb coffee. I think the same amount of power in electricity would cost me $50, or about $0.056/lb coffee. In other words, I don't think the cost of the fuel should be of consideration when it comes down to a penny a pound.
-Marshall Hance
Asheville, NC

germantown rob

#9: Post by germantown rob » Aug 19, 2011, 2:42 pm

My 2 cents on natural gas. The gas supply to a home is around 5"wc and my machine wanted 6-7"wc, I did resolve this by turning up the gas pressure at the main but this effects my burners on the stove a bit. It also locks you into one place to setup your roaster, not that my roaster is all that portable at 130lbs but still something to consider. On the plus side I will never run out of fuel mid roast. If I could do it again I would probably go propane and have a contract with a local company and a large tank.

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Randy G.

#10: Post by Randy G. » Aug 19, 2011, 5:18 pm

Arpi wrote:Yes. Infrared is "light" emitted by hot bodies (your body is emitting right now 'light')
...

I just put eight ounces of green coffee beans in my shorts to find out if you are right! :shock:
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http://www.EspressoMyEspresso.com