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The sweet potato is cooked
There's a lot of weird descriptions we use in coffee for many different things. It seems to me that a lot of it for me comes down to having a similar vocabulary or else it just doesn't make sense. One of the terms our Taiwan brethren use to describe a specific point in the roast is when the proverbial sweet potato turns from starch to a 'cooked' sweetness. Only the nose knows when that is!
If that makes any sense to you, you might be quite ahead of the curve.
There are a bundle of terms that we have from 'green' astringency to 'pencil lead' bitters and of course the 'baggy' and 'bakey' from a variety of variables. It occurs to me that the bakey descriptor is a hard one to quantify as it can be anything from a full on cardboard 'generic coffee' aroma to a simple oft unnoticed dulling of aroma and fruit. My favorite though is the term 'charr.' It's what we use to describe the caramel note imparted by the
perforated drum. For instance, you may bake corn in an oven vs over an open grill. The latter being our little roaster. Easy to burn and hard to cook through but the reward of getting it just right is an explosive balance of mid tones AND fruit in the same cup.
My least favorite descriptor is acidity and you won't see me use it much to describe a pleasant coffee. Acidity is really a misunderstood term so I propose we simply rethink it or at least use it more sparingly. It's just too all encompassing of the good and the bad without distinguishing either. Many strongly acidic coffees can often be attributed to either a roast byproduct(intentional or not) or a problem with the coffee. A bit green and improperly dried where the astringency is often erroneously described as acidic is something I have seen quite a bit of. When the acidity is pleasantly balanced, not a byproduct of error or defects, then I typically term it as
fruit which it will often resemble. A nice cup of coffee can have ample fruit character without closing your throat or turning your stomach. A fruity cup can be juicy or jammy but it shouldn't curdle your milk!
This one particular coffee we roasted tonight is a strong Kenya. Powerful aromatics and fruit in the cup like a pleasant Lychee or Longan fruit. Something tropical and sweet but I dare not say it's acidic in the classic manner. Past roasts where a green astringency showed through after days of rest were most definitely acidic/tannic/astringent. This roast was decidedly sweet and juicy with a popping aroma which beats down the roast we did only two days earlier that we were wowing over. It has a nice acidity but it's not acid nor acidic, therefore I just call it fruit and be done with it. Maybe acidity is a dirty word in many circles but maybe we just need to understand it a little better instead of throwing a big blanket over it all with one generic term.
I really believe building a vocabulary is key to quantifying many different things. Since we had nothing to point to, no guide, we defined our own roasts in our own terms. Mostly the errors as we saw them and quantifying the resulting tastes of those errors. This must have really confused our Taiwanese friends who did a double take at our desire for less 'roast' flavor in the coffee. I mean, coffee is roasted, so all the flavor is roast but we were so tired of that dull bitter smoke that we referred to it as 'roast' flavor. A singular note that stood out from the rest of the coffee flavors that was often simply akin to hardwood smoke.
Even in espresso, I use the term bile to describe one sour and acidic to describe another because depending on which is prevalent, you may need to decrease or increase the brew temp. Quantifying things in relative terms is just a simple aid to relating and understanding what you are tasting and relating what that comes from. Be it in the roast or in the brew method, a label helps even if it sounds funny or a bit silly.
Labels: descriptions, labels, roasting
The Green Monstah
Labels: bake, drying, green coffee, roasting
Scorching, tipping, baking
I wanted to write an article on tipping and scorching but when it came down to it, I realized we already covered
this bit so we won't go into too much detail.
A quick refresher. Scorching is the ashy dull taste visually indicated by a dark line in the bean. Tipping is a funny little black ashy mark on the end of the bean alluding to much the same off flavor.
Why does it happen?
Too fast, too much drying, uneven roasts, and cooling problems to name a few.
How do you fix it?
Know your roaster and the physics behind it. Use that to your advantage or change what part is holding you back.
In terms of roaster errors, baking is most interesting because it's quite common. Bakey in it's worst is this horrible flavor that dulls out everything in your coffee. It's like a cardboard flavored cake. Not really acidity or bile sour but like an intense gassy sour flavor. Baking is often stated as simply too slow. Well it's not exactly too slow, but if you want more detail, pay me to teach you. Ha, you thought this site was all idealistic and free info for everyone.
It isn't.
That's not really the point though. If you don't know what a bakey coffee tastes like or a tipped/scorched roast flavor/appearance, as a barista, how good are you really?
A roaster who consistently has this problem has no legit excuses but should a great barista understand those flavors when they appear? I used to think I knew my stuff but there were days
I really could not pull a good shot. It wasn't until I stepped out from the bar and really began to learn more that I began to expand my palate and because of the frustrations with a local roaster's inconsistencies that we were almost forced to roast. If you want a good cup, control it all from start to end, right?
Sounds simple but it's hard.
In fact, it sucked. It really really sucked. I can't put enough emphasis on how bad it was. I think we roasted more than 40lbs 250g at a time before we had a few drinkable roasts. Green, astringent, acrid, scorched, baked, flat, baggy, moldy, you name it, it was all swill at first. We tried profiles being floated by pundits and internet personalities, we did a little 'research' on roasters we knew to understand their approach. In the end, we found flaws in many and completely disregarded others going in our own direction.
Why?
Because every machine is different.
We had to learn our machine inside and out, make big changes and then keep roasting because roasting is very machine dependant and so many internal/external variables can affect a roast. Do we feel any closer to perfection, ask me after another 100lbs of sample roasts, but at least our mistakes and research are drinkable now and I am happy with the sweetness though it might need a little more 'Technicolor.' I dare not mention how much we have spent on green or the hours toiled behind a roaster tasting and making gut decisions about what went wrong. Most of the time, only two of us in an 85 degree room with tempers flaring and nothing to show for it.
Good times.
Will I write much more about roasting on the site, no, not in much detail anyway. My cups are pleasant enough that I have nothing to complain about so I will leave you with this.
Scorching, tipping, and baking....
Don't do it and don't put up with it from your roaster either.
Labels: baking, roasting, scorching, tipping
Huky Motor Replacement (aka "Let the Good Times Roll")

Based on the feedback of my recent roasts, I am convinced that the increased rpm (from 43 to 52) contributed positively. The roasts are more even and the heat transfer efficiency increased. The roaster response also increased slightly as the result of the higher rotation speed.
The next step in this experiment is to replace the stock motor with a higher rpm one and install a motor speed controller so the rotation speed can be profiled throughout the roast. After watching ebay for several weeks, I finally found a unit with the right rpm and torque that is affordable as well. I quickly snatched up the motor and eagerly waited for its arrival.
Here's a quick comparison of the new and stock motors (running at 24 VDC):
Stock motor:
Manufacturer: Shayang Ye Industrial Co.
Model#: RB400150-06202
Reduction ratio: 100:1
Rated speed: 54rpm
Rated torque: 6.1 lbf-in (97.2 oz-in)
New motor:
Manufacturer: Pittman
Model#: GM8723G567
Reduction ratio: 96:1
Rated speed: 86.5rpm
Rated continuous torque: 7.1 lbf-in (113.3 oz-in)
The new motor is a much heftier unit and the construction is very solid. It is also not cheap if purchased new. The NOS unit I got is very reasonably priced. As usual, trimming and fitting are necessary to get it go into existing housing. The current coupling sleeve was drilled to accept the circular shaft. I was initially concerned about slippage and mis-alignment, but so far it seemed to be fine.
I had originally planned to purchased a PWM (pulsed width modulation) motor control unit from ebay but after conversation with a very generous co-worker (Dr. Gizmo), he designed/installed a analog motor speed control for me. Below is his schematic of the circuit:

The new motor/controller setup allows me to vary the speed from 20 to 80 rpm. At speed below 20rpm, the tachometer no longer register the speed and I do not think such low speed is necessary. The maximum rpm dropped from 83 to 80 due to the voltage drop at the transistors. Noted that in actual use, the rpm will go up 1 to 2 more when the roaster is fully warmed up.
This latest mod puts the little huky a step closer to a "commercial" sample roaster that I desired. I am very excited to start experimenting with speed profiling and anxious to see if it can solve one of the remaining deficiencies of the roaster.
Labels: gear, huky 300, roasting
Tachometer for Huky300

Bicycle tachometer modified to fit and measure drum rotation rpm. This is done in anticipation of future motor replacement (of a higher rpm unit) and addition of variable speed control. Goal is to have drum rotation as part of the profiling, in additional to gas and air settings.
I replaced the stock 20vdc adaptor with a 24vdc unit, which "restores" the stock motor to it's default speed. The "as-purchased" configuration down-rated the motor (reason unknown). Drum rotation increased from 44rpm to 52rpm.
Trial runs already showed differences in the profile. At first glance, roasts seemed to be much more even at the higher drum speed. How it affect the cup will be determined in the coming weeks...
Labels: huky 300, modification, roaster, roasting
The beauty of the 'Double Roast'
A double roast is not something I would recommend for any good coffee. It's a roast where a normal profile is begun but as the coffee coffee progresses in drying to a point where it begins to gray, you dump it and cool the coffee. You then warm the roaster up to a much higher temp and drop the now cooled green back in and attempt to continue the roast. The resulting cup will be a polished, very low acid and extremely 'coffee' tasting coffee. It will have no fruit and little unique aroma, the roast flavors and the woody coffee notes will be all that remain of what is now an entirely generic coffee.
I guess I could understand this for someone roasting C-Grade who desired heavy body and low acidity. Then again you would wonder why someone like me would even be talking about this.
We were roasting today and were struggling getting efficient drying on what we believed to be a particularly good coffee. Knowing it was good made it more frustrating. At one point during a drop, a mistake in the flame setting caused the roast to begin to tail near the end of the drying phase. On the spot Ben decided to just dump it and cool it. He pulls out the old Japanese book on slow roasting and chronicles the 'delights' of the double roast. Having accomplished most of our goals for the afternoon, we decided to go for a double roast. A roast later, we had our double roast and a few new observations.
We pondered the exhaust and how the heating element was reacting with the barrel. Then it came back to the flue. Most roasters simply have an on or off while the Japanese and Taiwanese models have a variable control. Based on the discussions sparked by the double roast, we were able to ascertain we needed more efficient venting. Ten minutes of tinkering and we had a ghetto fabulous chimney fan combo increasing our drying efficiency. An ugly but entirely useful hack!

Sometimes things we know are dead ends are worth pursuing simply for the experience.
Labels: musings, research, roasting
Tipping the roast
Tipping and scorching are roasting errors which lead to an uneven roast. You can read more about this topic in this brilliant article by Willem Boot.
Photography by Ben KaminskyA
friend once addressed me saying that I surround myself with many people who don't scorch or tip and I began to see that as the norm. I didn't disagree but the truth is we have dealt with this particular subject for a long time to the point it is affectionately called the
New Flava Roast or the 'single bean melange' in mockery.
The particular flavors that come from this are not enjoyable in the least. You have vinegar and ash in the same cup where I can honestly say it would take an odd palate to put wonderful descriptors to this one.

Photography by Ben KaminskyInterior scorching is identified by this layered coloration. You can have defined unevenness which will lead to a fuzzy taste profile and a murky cup. There are no layers or clarity in the cup and no distinct flavors. Often unpleasant and if you didn't take the time to crack open a bean and examine the interior, the outer coloration would look normal.
Pay attention to your roasts people!
Labels: roasting, scorching, tipping
Video: Roasting and Sugars - Mr. Arno Schwenk
Ladies and gentlemen, Mr. Arno Schwenk!
Roasting class from the Nordic Barista Cup thanks to Kaminsky for making me post this.
Brilliant.
Labels: Mr. Arno Schwenk, roasting, video
New Flava Roast!
Fan of Philip Morris?
Think
Jay's signature drink is heaven in a cup?
Then you will love the New Flava Roast coffee.
With this signature style of roast, you get a STRONG, ROBUST but SMOOOOTH smoky flavor in your coffee, REGARDLESS of degree of roast.
Now you can enjoy your bright and lively Kenyan with a overtone of cigarette, or your mild Brazilian with a touch of pipe tobacco.
It's like drinking coffee and smoking at the same time without the side benefit of lung cancer and nicotine addition.
Simply amazing!
Labels: roasting
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