Hi Guys,
Want to warn you beforehand that this might be the stupidest thing you might read all day. However, I just wanted some opinions on this thought I had earlier today:
This thought stemmed from the whole particle size distribution/uni-modal grinder discussion that is doing rounds on pretty much all coffee blogs. The basic reason behind the formation of microfines, as I understand, is the brittle structure of the roasted coffee bean. When the brittle bean is broken/crushed fines are produced.
On a completely different note, there is a consistent discussion going on in homeroasting forums about the roast level of the internal bean vs the external bean.
When we combine both these discussions a question comes to mind: Why not grind the bean before roasting it? Green beans are way less brittle and hence would produce very little fines. Since there wouldnt be an internal and an external 'bean'(!!) anymore, there wouldnt be a question about uneven roasts.

I know it sounds REALLY weird but would love to get opinions on this!

Cheers,
Sid

It's not a stupid question. Just one problem of many that come to mind would be the grinder that it would take to effectively grind something into a certain particle size that consistent, if such a machine exists, it's not going to fit in my coffee lab (living room).And I doubt it would be cheap enough for a large portion of the 3rd wave coffee to adopt either.

Second, what sort of machine could roast pre-ground coffee? Again, some complex industrial unit with very controlled filtration of air flow, maybe, but I doubt it. If there were a way to do this and have it even slightly more affordable than pre-existing mass industrial roasting methods, then I imagine it would have been done already for the instant coffee world, but why would they go thru all the effort? They aren't chasing quality, they're chasing quantity and economy.

And for the imaginary world where we could somehow do this effectively at home, for a reasonable cost, what would you do if you needed a different grind? You certainly couldn't grind it again.

What I can't understand is how greens could be ground at all without 'loading' the cutter be it a burr or whatever else would be used. Greens maintain a certain moisture content. My guess is that it would be the same concept as processing wheat or corn for flour. And as Tom mentions, how can that be replicated to fit a home user?

I am sorry I didnt clarify in my previous post. I meant that if we were to use say a burr grinder to grind green coffee we would get practically no fines due to them being a bit more flexible due to the higher moisture content. Am i not right in saying this?

TomC wrote: And for the imaginary world where we could somehow do this effectively at home, for a reasonable cost, what would you do if you needed a different grind? You certainly couldn't grind it again.

My stream of thought didnt go that far. However, it could be effectively incorporated with a roast -> grind -> brew kind of machine that another thread here. The biggest criticism of that idea on that thread is that there wouldn't be enough time to degas. In all probability you wouldn't require degassing time in pre ground coffee. Obviously all this is speculation at this stage!!

I know we currently dont have a machine that would be able to roast ground coffee but I think if we could try it out in a wok or something we would get an idea about whether its an idea worth exploring more or not. What do you guys think?

stoned_survival wrote:I am sorry I didnt clarify in my previous post. I meant that if we were to use say a burr grinder to grind green coffee we would get practically no fines due to them being a bit more flexible due to the higher moisture content. Am i not right in saying this?


My stream of thought didnt go that far. However, it could be effectively incorporated with a roast -> grind -> brew kind of machine that another thread here. The biggest criticism of that idea on that thread is that there wouldn't be enough time to degas. In all probability you wouldn't require degassing time in pre ground coffee. Obviously all this is speculation at this stage!!

I know we currently dont have a machine that would be able to roast ground coffee but I think if we could try it out in a wok or something we would get an idea about whether its an idea worth exploring more or not. What do you guys think?

Eh, not sure I want a single grind as TomC pointed out.

Also, you'd be losing crack as a data point, I'm not sure the ground coffee would do much in the roaster other than bake.

And without drying the beans somewhat, you'd likely end up with green coffee butter clumping to the burrs. And I'm sure the delicate aromatics would appreciate all that friction and heat build up.

I'm pretty certain it wouldn't work at all for any kind of espresso prep, you couldn't grind fine enough and roast it properly. But I guess as an off the shelf test, someone could stop a typical roast right at the drying stage, then let them cool down a bit, run them thru a grinder and then get creative on the roasting. But I bet the wok idea would result in burned particles (and their flavor compounds) mixed with lots of improperly developed particles. But it might be fun for someone to play with. I highly doubt it would lead to better end results, that's for sure. So I'm not too motivated to try.

It's not a stupid question.

Although I suspect that all of the reasons for "it can't be done," raised by previous posters are correct, like your hypothesis (roasting ground greens can be done), their counter-hypotheses can't be tested absent actual, physical experimentation.

The question is not a thought experiment either. Those don't require empirical testing. My favorite thought experiments were constructed (thought?) by Einstein, demonstrating aspects of special relativity. But wiki cites Schrodinger's Cat and Maxwell's Demon as illustrations.

BDL

So the beans in a sealed drum roaster exist in two states, or one super-state, of being both roasted and not roasted, until you look?

What you propose means the end of the first crack for sure as although the particles will still expand, I doubt they would pop. Will there be a second crack? What about the sugars inside the whole bean? It's almost comical, but not a stupid question at all. HMMM!

kajer wrote:So the beans in a sealed drum roaster exist in two states, or one super-state, of being both roasted and not roasted, until you look?

Yes but only within the Higgs field.