1 Attachment(s)
coffee for mags - a coffee roasting trip report (& free mag coffee)
Quote:
Originally Posted by
doebedoe
Espresso is delicious, bougie, and nerdy but totally unnecessary!
You did leave out one thing: to brew truly excellent coffee a scale is not optional. $11.99 https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Copying this over from the espresso thread for reference since I straight Pio'd my first Kenyan yesterday.
Quote:
Originally Posted by
tgapp
Attachment 405151
red check-shaped line = how hot the drum is
blue check-shaped line = how hot the beans are
blue squiggly down line = how quickly the coffee is heating up (how many degrees a minute the coffee is getting hotter) - this is called rate of rise. the goal of this exercise is to make the squiggly blue line go down at a consistent slope angle. major deviations in slope angle = problems with your roast, and the later in the roast they are, the bigger of a problem they represent.
this profile is of a notoriously hard crashing kenyan. i drew in some unscientific lines in there (the black lines) along the rate of rise curve to demonstrate what a crashed coffee looks like. notice how the slope of the line changes dramatically right around 6:50, roughly ~30 to 45 seconds before the coffee started popping like popcorn (first crack start). this coffee was fine, but not great.
this isn't an apples to apples comparison - different roasters meaning that the temperature numbers are not comparable, so ignore them, but just notice how the shape of the lines are totally different. here is the same coffee but one where i actually managed the rate of rise crash decently well. not perfectly, but decently well:
Attachment 405152
you can see that the coffee started to crash (just like the last one), but then i got control of it and kept it from bottoming out. the average slope angle of both "sections" of the roast are very similar. this isn't a perfect execution - but this coffee is EXTREMELY hard to control, and this roast was MUCH MUCH MUCH better - noticeably sweeter and more delicate.
anyway sorry for the nerdery thanks for coming to my tech talk use a fucking thermocouple JONG and your coffee will not suck
Quote:
Originally Posted by
tgapp
yeah i would not have been able to figure this out if i didn't give away a ton of coffee. so, i'm definitely self-interested here, and it's helped me out a ton. i actually think i could have a decent shot at going pro if i wanted to now, but i'm not sure i want that.
managing a crash is really hard - part of it comes from knowing the beans (fucking goddamn kenyans always crash, all the time) - part of it comes from fucking it up a ton. but the basic theory of gas management (heat) during a roast cycle is that right around 50 seconds into the roast, you go full heat, and then from there, you only turn the heat down (the dial only goes one way, so to speak). i need to start including gas annotation notes in my roast curves, which is what real professionals do. i will shortly.
so in a typical roast, it'll look like this. for reference, i'm using the event "dry end" to measure relative times. none of this is absolute, it's all relative to when the coffee reaches 300 degrees +/- (again depends on the roaster, but this is when the coffee changes from green to yellow and begins the maillard process - like browning on top of your lasagna or your creme brulee - i see you, kitchen torch and fried rice in the watcha cookin thread).
100% heat @ turn (when the check mark starts to go up again - roughly 50 seconds in) - coffee is approx 180 degrees. no changes until the coffee is dry and it starts to brown.
90% heat at dry end (3:00-4:30 in depending on the coffee) - coffee is now 300 degrees +/-
80% heat at dry end + 30seconds - 315 degrees +/-
70% heat at dry end + 1min - 325 degrees
60% at dry end + 1min30s - 335 degrees
50% at dry end + 2min - 345 degrees
40% at dry end + 3min - 350-355 degrees
20-30% at t-minus 30 seconds to 1cs (a roast profiler can estimate when you cross that threshold so you are able to anticipate it)
15% at 1cs + 30 to 45 seconds (so we wait until 1cs gets going to make another adjustment)
0-5% at 1cs + 60 seconds until roast end (many roasts get ended right here, some go as long as 2 minutes after 1cs, especially those intended for espresso because you need the extra sweetness and body to balance a shot that comes from an extended first crack - what we call "development time" and is represented by the percentage of the time after first crack relative to the overall roast time. so, if a total roast time was 10 minutes and two minutes of that was spent after first crack, you would have 20% development time - a decent benchmark for espresso)
if you do not follow some structure roughly like the one i described, ALL coffees flick and crash. if you do follow the structure above (give or take as it is all relative and so much of this is art and practical knowledge), some coffees (fucking goddamn kenyans) will still crash because they are little ungrateful spiteful shits and all they want to do is ruin your day.
so, to prevent a crash in a malicious little shit of a coffee (kenyans, lots of geisha, other high-grown coffees like some washed ethiopians), the basic theory is that right around 1:30 BEFORE first crack start, you would, say, go from 40% gas all the way down to 10% gas. this creates thermal "space" in the roast so that when the coffee heats up from releasing water (remember, during the first part of the crash the coffee gets momentarily hotter), it isn't being egged on by additional heat in the drum. turning the gas WAY down prematurely smooths out the first half of the crash, and then, at around 45 seconds before first crack starts, you turn the gas up again back to 30-40% (in principal violating the first rule of coffee roasting, which is that the heat dial only goes down during a roast), but that, in turn compensates for the second part of this pattern, where the additional moisture in the drum lowers the overall thermal momentum of the roast.
this technique is called a gas dip and is very hard to execute well - you can see i tried to execute it in my 2/1 profile i shared but my timing wasn't perfect - still, i'd say that coffee cupped at around 87, with a total potential to cup at close to 89 or even 90.
anyway sorry this is a ski forum but yeah probably like 95% of commercial roasters don't manage flicks and they also source shitty coffee and that's why i think objectively that my coffee compares to $25-30 bougie bags because it's really fucking hard to train someone making $15 an hour to manage a roast
the roast:
Attachment 422875
coffee for mags - a coffee roasting trip report (& free mag coffee)
Quote:
Originally Posted by
tgapp
Goddammit I am jealous
Let me know if you pull the trigger on the full bag
Sent from my Pixel 6 Pro using Tapatalk
Looks like it’s sold out.
I’m going to trial a few 100g charges of the other Galo this weekend before I try this one.
