First oil

[simonp]

"First oil" - this is a phrase I've seen a lot quite recently, and reading the roast instructions for Malabar Gold, this is also mentioned here.

I have yet to observe this with the modded popcorn machine. I have tried darker roasting than my "norm", say to 45 seconds into 2nd crack, but no oil on the beans, though I do see visible smoke. The airflow is quite strong on the popcorn maker so I'm wondering if the oil is getting burnt off making this point difficult to dtermine. Anyone else experienced this?

[mnemonix]

I have speculated before that air roasting may produce a roast that, initially at least, shows less oil. I haven't dared roast far enough to get completely shiny beans but can get spots of oil (what i'd describe as first oil) and it occurs quite some time after visible smoke !

I think the only way to get a feel for it or research it further is to bravely roast on to charcoal and observe the stages. You probably only need do it once, and best start off with the assumption you're not going to be drinking that batch (unless you're Tisri )

Chris.

[simonp]

I did try once, I roasted WELL into 2nd crack, about 1 1/2 minutes aftre the first pops, 2nd was still rolling well with no slow down, but I chickened out and stopped, still no visible oil, there were a few spots a day after the roast, but not that much. The beans didn't taste that dark either, not much of a smokey taste, but did require a finer grind than my usual roasts.
It makes me wonder just how dark Charbucks go to get that really dark taste!

I might try going the whole hog this weekend (weather permitting) and going to the end of 2nd, it just seems a shame to waste good greens. I wonder what beans would not be completely ruined by this level of roast?

[mnemonix]

robusta ?

SMs recomend roasting Aged Sumatran Lintong to Vienna, but personally i'd just choose something more innocuous to experiment with. I might try with a regular Sumatra.

Is there a possibility that the roaster isn't getting hot enough to produce this dark a level of roast ? i would have thought the smoke indicates that it does, but never having pushed a roast for long enough i wouldn't really know.

Chris.

[simonp]

I never run at full heat with the Rival, the temp rises rapidly enough befroe getting to full heat. I was thinking of lintong too.
You have a Rival too don't you? I must admit I am impressed with its durability, you hear a lot of stories about poppers not lasting long doing long roasts, but I have done lots of circa 20 minute roasts with no problems, even over-running the motor at 24V smmes OK, but I guess there is little load on the motor, so the current is quite low. I also find that you can do up to 160g roasts (with chimney) which is good.

[phil]

One thing to remember is that when you dump a roast you may briefly see spots of oil which disappear back into the bean fairly quickly as it cools. I have seen this with otherwise relatively light (but into 2nd crack) Hottop roasts a number of times.

I don't know what people actually mean by "first oil" but I could reasonably speculate that the above is it.

[tisri]

Since I've been named again I'll chuck in my experiences of getting the oil to show in a roast. I've found that the beans get slightly oily some time after second crack starts but, as Phil says, the oil often soaks back into the bean.

The only thing I've roasted really dark (well, by my standards anyway ) are espresso blends which often appear slightly oily in the drum of the Hottop, then appear drier after agitation in a colander (to shake off any remaining chaff) and subsequently become oily again when left to rest in a vacuum bag. The last batch of espresso I roasted was particularly dark (I think about 90 seconds from when second crack got underway, or a total of about 21 minutes) was oily enough that I could wipe it off my hands after handling a couple of beans.

[tisri]

You probably only need do it once, and best start off with the assumption you're not going to be drinking that batch (unless you're Tisri )

Awwww.... this is turning into the "Pick on tisri" forum

Even I haven't managed to charcoal a batch yet!

[simonp]

One thing to remember is that when you dump a roast you may briefly see spots of oil which disappear back into the bean fairly quickly as it cools.

Never seen this with the popper, the bean surface always appear dry throughout the roast, the only time I see oil is after some time (1 day min) in the one-way valve bag.
I guess the spots just get dried away by the high, hot airflow.

[mnemonix]

The advantage of going home for lunch is that I can roast...

120g Sumatra Iskandar Triple-Pick
1st snap of 1st crack 203ºc, 10m 30s
1st snap of 2nd crack 234ºc, 14m
smoke at 240ºc, 15m
oil showing 247ºc
shiny beans and stopped at 253ºc 16m

profile graph and picture of beans below.

[mnemonix]

oh, and smoke alarm, 16m 30s

and i forgot to mention 2nd crack was still going when i stopped the roast.

chris

[simonp]

Thats WAY darker than anything I've roasted , it does look rather like Roberts dark roast blend (forgot the name) or H&V San Giorgio, but may be darker than it looks as my monitor tends to display things on the light side (TFT).

247C is 477F, which is much higher than I've seen people say for first oil, so perhaps the first oil that you see on a drum roaster doesn't show with a popper.

Are you going to try the beans?

[mnemonix]

Well the temperature is 'subjective' and shouldn't be taken as an absolute due to the variations caused by thermocouple position, calibration and so on, your measured temperature may be different from mine.

Of course i'm going to try them ! they're by no means charcoal and look to me very much like any other dark roast i've seen in coffee shops and cafés... they might even be an improvement for my cappucinos though probably still not dark enough for tisri. oh... i really didn't mean to say that. sorry tisri

[simonp]

My thermocouple is a bit low in the chamber, about 1" from the bottom, but I keep forgetting to drill another hole. My temps are probably a little out due to this, first crack often doesn't start till 210-215C.

[tisri]

Those beans look good to me. That's what I'd call a good dark roast. For espresso maybe go a little darker, but not much.

Just to keep everyone surprised, I'm going to review a coffee and am expecting to have to say something that will shock everyone....

And Gah! I'm still being picked on