Does type of heat affect roast profile

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

#1: Post by espressme »

I have heard that a gas flame from a properly adjusted burner has a moisture content and is therefore different than a dry heat. Does or would this be a factor in roasting? Just to name two roaster types. Say between an electric drum roaster and a gas heated drum roaster?
Richard
richard penney LMWDP #090,

CoffeeOwl

#2: Post by CoffeeOwl »

Richard,

there is a difference in bread baked in electric oven and in gas oven. Chinese medicine also claims type of heat has importance - basically it says that electricity is not enough substitution for fire and from that we can have a sort of lack of energy, vitality and similar problems.
Now moving onto the unhealthy examples, smoking. I used to smoke (I happily quit and recommend it to everyone 8) ) and I smoked cigarettes, cigars and pipe. I experienced how the type of heat affects the taste of the smoke. The gas flame is worst, matches are better, petrol lighter tasted best and also a very unique was the taste of the smoke started from a fireplace - like with a piece of burning twig etc. Maybe the type of the twig would also matter. I haven't tried coal as lighter.

Yet for the coffee beans my intuition suggests that electricity would do. Yet again this same intuition (but accompanied with a bit of reasoning) sets me against freezing (both greens and browns).


EDIT

Oops. I read it 'does type of heat affect coffee taste', sorry for the off-topic :oops:
'a a ha sha sa ma!


LMWDP #199

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John P

#3: Post by John P »

I think the short answer would be "no".

This of course implies that you are adjusting to the roaster at hand rather than transferring profile 1 from roaster A to roaster B.... you may need profile 1a.

If the roasters are exactly the same, but one is electric and one is gas, the difference will be that the gas ones tend to respond more quickly in to adjustments in heat. For electric ones, you need to think ahead perhaps 20-40 seconds depending on the roaster.

If they are two completely different roasters, then they need to be treated just as any different sets of roasters would. Direct heat? Ambient Heat? how much convection... etc. Is the air flow comparable? how is the drum design? drum speed? etc. So the resultant flavor may be more to the overall roaster design than just to what type of heat it uses.
John Piquet
Salt Lake City, UT
caffedbolla.com

scottfsmith

#4: Post by scottfsmith »

Gas-fired gives you much more natural convection -- the air moving in to feed the flames generates a significant flow. When I was a kid my parents had a fireplace with glass doors you could shut so only a vent was letting air in. You could feel some major airflow heading in there. With electric all you get is the "heat rises" variety.

Scott