How to get that sweet taste in own blend ?

[Steve]

Ambient and bean temp are indeed difficult to work out. Its changes through out the roast, but on my roasters you can guess bean temp around 20 Fahrenheit lower than the ambient, until around or just before first crack when the exothermic reactions kick in and then its around 20 deg Fahrenheit above the ambient. But this is all very basic and not very scientific.

Steve
(waiting to be shot down for dumbing it down to much)

[Gouezeri]

(waiting to be shot down for dumbing it down to much)

My kinda level

[CakeBoy]

Sorry ... I don't understand the dumbed down version

[Monsooned_Bean]

I got a question about pyrolysis process for coffee beans. Does anyone know exactly what's happening chemically inside the beans after first crack ?

I'm wondering about what would be the best way to treat different kinds of beans after first crack - i think that's where it's getting interesting.

Should you lower or keep heating temperature constant after first crack, because the exothermic reaction will produce enough energy / heat to raise the interal bean temperature itself. If so, by what amount ? For how long ? When should you start to raise temperature again, before beans get killed because of too long held temperature ?

And furthermore - why does it kill a beans taste when it's kept to long at a certain temperature ? Because all acids of a certain kind are reduced completely then ?

I know all this will depend on the origin and treatment of the bean you're roasting, but there must be some general things about it to say.

Perhaps someone can share his / her knowledge about that or will know link on the net with some info on it ?

EDIT: Here's a link I found, unfortunatly only in german:

http://www.uni-bayreuth.de/departments/ ... affee1.htm

[Steve]

How long is a piece of string same old answer I'm afraid.

First crack and second crack is the oils inside the bean beginning to boil (simplifying again sorry) and causing the bean to expand. That expanding is what creates the heat in the bean. Its important to keep some heat going into the bean as this will soon die off, its not a great deal of exothermic reaction.

It must always be an upward curve.

The taste changing with drawn out roasting and beans that drop below there temp then back up is like cooking food. If you over cook something it becomes tough and baked and not nice. You get two chances with the cracks and if you don't get it right its no good. Coffee is a very complex food group with over 800 parts making up the taste.

You will have to excuse me but I seem to have lost the skill of articulating myself over the past few days, a weekend resting is what's needed.

Steve

[Monsooned_Bean]

Thanx Steve for your answer. Well I don't see your problems articulating yourself - but I wish you a recreating weekend though

I guess my programs on the I-Roast all keep an upward curve, like:



What I was looking for is some kind of table or general overview, which could look like: [But my hope is decreasing such a table might exist]

Name of Acid / Substance / Matter / Group of chemical Substance behaving the same way: "Funny Acid"

Kind of Reaction: "Funny Maillard Thing"

Beginning at temperature: "Funny amount of degrees"

Effect of Acid on Taste: Tasting not funny in high concentrations

Acid Derivates: Funny Derivate, caused by funny effects

So that you could make thoughts about where to keep temperature constant and where to rise faster in order to keep more or less of the acids unchanged.

Surely not possible for all 800 parts making up the taste, but for the most important and yet known. And not even talking about chemical differences which depend on the origin of the roasted bean.

Jan

[Steve]

The acidity is controlled far more by the processing and growing than roasting ever would. I think your search for the table will result in that it doesn't exist. There are just far too many variables involved (more so than espresso even).

Roastings a tough job that's 60% science and 40% experience and trying to pass that experience on to some one is so tough. When do I know something is ready, why do I know this style of roast will suit this particular origin? I cant tell you most of the time, its just what I do. Let your taste buds do the work, ultimately that will tell you if something is right or not.

and the weekend will be used to try and relax the brain

Steve

[CakeBoy]

Having had the honour of watching Steve roast a batch and witness the calm way he just made it look like nothing as switches were flicked on and off to adjust temperatures and produce a profile - all from his experience and pulling out a few beans to assess as things progressed - to me it appeared more of an art form requiring a true gift. Needless to say, I was one impressed puppy

In fact, my whole regime improved 100% just from watching and listening to Steve.

[CK]

Use some Daterra in your blend.
Or PB Sigri.

[Monsooned_Bean]

Does anyone know about differences in sweetness concerning sweet yellow Bourbon from Brazil ?

What I mean is : Is the Daterra that much sweeter than other beans of the same kind but not from Daterra farm ?

[Steve]

Each farm has its own properties, so its really difficult to say. The Dattera coffee's tend to follow the sweet profile, but then so do many other Brazilians

Steve