home roast dictates too fine a grind?

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
LeoZ
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#1: Post by LeoZ »

It seems that, and i could be wrong, but it seems that when i roast myself, i have to grind finer than if i buy preroasted beans. comparing Caffe Frescos last order (which was still fresh, obviously, i received it 2 days after roast) to my roasts, if i dont get the grinder down to having the burrs rub, my shots come out 5-7 secs too fast. since i roast 99% of what i drink, this is obviously a problem.

Ive swapped beans with a friend who commented the same, without me mentioning it to him. same bean/blend, same pull (double ristretto) and my beans have to be ground finer.

any ideas why? is it a grinder thing? a roasting thing?

Thanks.. :?

Zzyzx

#2: Post by Zzyzx »

For me the grinder (Macap M4) adjustments seem to very from coffee to coffee, not sure why, maybe a different molecular compositions or something.

So, just on my home roasts I don't seem to be making adjustments for a finer grind, just when I change to a different coffee altogether.

Let me add, I use a RK Drum for my roasting

ZZ

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another_jim
Team HB

#3: Post by another_jim »

I think it's air versus drum roasting. I noticed this too a few years back and wondered what the real reason was. Then a friend and I did an experiment, same beans, same roast profile, me on an air roaster, my friend on a hottop. Sure enough, the hottop beans needed a coarser grind.

The flow in espresso is controlled by fines. Presumably drum roasted beans are more brittle than air roasted ones and produce the same amount of fines at coarser grinds. Since one generally needs to grind finer when beans age and get soaked in oil (in the raw bean, the oil is held in vacuoles); I'm guessing air roasting somehow accelerates this effect.
Jim Schulman

LeoZ
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#4: Post by LeoZ » replying to another_jim »

makes perfect sense. my friend is using a hot top.
thats rather frustrating. dont want to ruin my grinder b/c it cant keep up with air roaster bean needs :/
thx for the reply jim

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farmroast

#5: Post by farmroast »

Leo How was the comparison of roasting times and general profile. There are so many ways to get to a roast level and it would seem like each will change many dynamics in the finished product and its brewing character. The amount of air convection must have an effect on the beans but I'm not sure whether it's a good one or not. Only have about 125 roasts with my BM/TO roaster and I've still got many more before I will truly understand my roaster. It takes a lot of practice to learn to play an instrument well.
Ed
LMWDP #167 "with coffee we create with wine we celebrate"

LeoZ
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#6: Post by LeoZ » replying to farmroast »

times are hard to compare. hot top roasts tend to be in the 19-20min range, and the most ive gotten out of my SC/TO setup is 13-16mins.
i tend to hit first crack around 7-8 mins, second around 11-12. im wondering if i should try to extend first crack to start at around 11.
im pretty baffled at the roaster setup too. certainly seems to be more variables than my popper before this.

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farmroast

#7: Post by farmroast »

Been aiming at about 11min fc too. Tried one about 7-8 last week and didn't like it as well. today tried a 2# roast and stretched to(slower to start but ramped up just before fc) 13 fc and finished a little into second but not yet rolling at 20 even. Had a nice finish smell. Been using some really nice Costa Rican that I stocked up on in sept. so my bean when I roast is the same for test purposes. I really like the variability in our style of roaster. Think they have the best chance someday of getting a god roast!
Ed
LMWDP #167 "with coffee we create with wine we celebrate"

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cafeIKE

#8: Post by cafeIKE »

another_jim wrote:I think it's air versus drum roasting. I noticed this too a few years back and wondered what the real reason was. Then a friend and I did an experiment, same beans, same roast profile, me on an air roaster, my friend on a hottop. Sure enough, the hottop beans needed a coarser grind.

The flow in espresso is controlled by fines. Presumably drum roasted beans are more brittle than air roasted ones and produce the same amount of fines at coarser grinds. Since one generally needs to grind finer when beans age and get soaked in oil (in the raw bean, the oil is held in vacuoles); I'm guessing air roasting somehow accelerates this effect.
I have a HotTop and FR, both moderately modified , allowing me to duplicate profiles very closely between the two devices. When the profile is close, there is not much difference in grind settings.

I experience much more grind variability with single origins than I do with blends. Had to open up 3 full turns on the M4 for a SO Harrar relative to my current blend. Both beans roasted to the same degree on the same profile.