I want some coffee!

I just roasted a bunch of coffee. To try to keep the roasts consistent using what RT3 (the roasting software) refers to as Recipes. Recipes are a set of button pushing commands to the roaster that can be based upon Time (the default) or Temperature AND Time (that's the logical AND meaning both). They provide consistency that seems to be lacking when I just follow the button pushes of an earlier roast. Easy-peasey. But the results have been inconsistent and I end up with roasts that have a graph that varies a lot. And I mean a lot . Thru some odd accumulation of good fortune I did a roast that seemed to have all the right shapes to the curves that are recorded during the roast. At the same time I needed to answer a few questions from the software developer about how the Recipe feature works in RT3. So... I decided to create a new version of the Recipe using the roast that had come out *looking* like I wanted. But instead of using the in-built roast-to-recipe conversion which is mech...

...but it was 5 lbs of some really nice organic coffee from the Chiapas region of Mexico. I just posted a map of the Chiapas region a few posts back so I'll insert a chart of the roast instead. This is the first of 4 roasts and is representative of how they all went. I've been using Drum speed to manage the Rate of Rise curve (RoR) and that seems to be working pretty well. The plan is to get RoR to fall steadily to something below 10F° from first crack to the end of the roast without stalling the roast. I did a fairly good job on this one but I can't *really* say I did great till I get to taste it in about a week. But at least I have coffee to pass out tomorrow that I don't have to worry about since this is the variety we're enjoying right now. Sweet and chocolatey which is my main criteria. And this is pretty much the look of the new software as development for RoasTime 3.0 starts winding down. The changes aren't dramatic but it just feels a lot better. It'...

 I've been struggling with managing the slope of the Bean Temp curve (data from the thermocouple) after 1C. The slope of the line would just tank after 1C got going. Nothing I did seemed to adequately affect that plunge and that threatened to stall the roast. I had looked at a bunch of roast data (most of the 350 roasts I've done plus roasts from other people) and I saw varying degrees of the same problem (at least I see it as a problem). I had tried several things involving power changes and varying fan speed but they just didn't seem to have the controlled effect I was missing. Then I recalled that I had been working with slow drum speeds at the start of the roast, gradually increasing drum speed from D4 to D8 just before 1C. When I thought about what slow vs fast drum speed meant to the beans, I realized that at slower drum speed the beans are staying in contact with the drum for a longer period. Yes, they drop away sooner because of less centrifugal force but the total...

 ... was a foundation built on sand. I'm still struggling with a plan to manage heat at the end of the roast. What I thought I knew, now that I did a chart-by-chart review of over 300 roasts, turns out to be a bunch of roasts with poorly managed heat. I've had this issue from the beginning and apparently just excused the error with "I'll do better next time" with no real plan how. Back to the drawing board.

In the last post I was wool-gathering about heat management at the end of the roast. A little research has helped plug a few holes in my memory.  I reviewed some of the early roasts I did 17 to 20 months ago. I was certain I did things better 'in the good ol' days'. But the evidence was undeniable- I had convinced myself about the good ol' days, but they existed only in myth. As Merle Haggard reminded us, "things were exactly as I choose to recall". What I saw in the charts, however, was the same collapse in RoR starting at about 1C. Exactly what I'm whining about today it's just that I wasn't conscious of the issue. I also looked more closely at the greatest difference between a recently cleaned Drum Temp sensor (IR) and the Bean Temp probe (thermocouple). These days I see about 45F° max difference, but over a year ago that max difference was about 65F°. I had speculated that the difference (65F° vs. 45F°) had to do with using higher Preheat, but ...

Before Blogger shit-canned my work for the 3rd time, what I wanted to post about is my issue surrounding the runaway loss of heat at the end of the roast. I didn't have to deal with it when I started with the Bullet back in Jan 2019, but it's a familiar quirk these days. I whined to an internet acquaintance about it and Stuart's feedback was phrased in just the right way to make me see what I've changed that needs to be unchanged. He said: As you note, one of the perils of the Bullet with it lacking any significant thermal mass is once you drop off the cliff with thermal momentum, you’re kind of screwed. I had whined that I was already at P9 (the highest power setting on the Bullet) and 'there's nothing left in the tank to get heat into the drum'. This has been happening at the end of the roast as 1C starts. Rate of Rise (RoR; the 1st derivative of Bean Temp) measures how fast temperature in rising in Fahrenheit degrees per minute (F°/min). As long as the ...

Kind'a out of the blue I received a shipping notice. I had guessed So. Korea was still shut down but there was unreported activity at the December Dripper factory! The 2 drippers arrived in perfect shape and work exactly as advertised. What's unique about their design is that they are throttle-able. You can set the base to expose 3, 2, 1 or 0 drain holes in the base of the dripper. That means the user can control the flow rate and ultimately the amount of extraction time during brewing. My first try was with some decaf which came out so strong I thought I might grow hair on my teeth. Apparently S. Koreans are studly coffee drinkers and have my utmost respect! Using their recommended ratio of 300 gm water to 20 gm coffee (15:1) was more than I could handle. Our usual ratio is 410 gm water to 20 gm coffee (20.5:1). A second try a few days later gave me about what I was accustomed to with better flavor extraction. At first blush I'm very impressed. But the process is complicat...

The new Berkey 'Royal' water filter is really everything it was said to be in terms of water taste. But the proof is in the cup and I was emphatically not impressed with the first taste of Colombia Timaná; C, however, thought it was great. When it comes to water, one of the things that can ruin a cup of good coffee is water that lacks minerals (think water softener). But the Berkey does not remove dissolved minerals from the water. And as good as it tastes I have to think that's right. We use #6 Melitta filters to drip our coffee (not this but close). I expected good things with the great water coming from the new Berkey. But to my taste the coffee was blah and I thought more acidy. Both C and I have years of using Melitta filters, in my case going back to about 1955. I remember reading the instructions that came with that porcelain filter holder telling the user to pour about 1/4 of the water to wet the coffee, let it sit about 45 sec, then slowly add the rest of the water...

I posted a little about buying green beans from Sweet Maria's. SM really makes it easy since they cup everything they sell and make those result available to the customer. Helps me feel I can rely on the descriptions they write (not a universal approach with coffee importers). Even with detailed cupping notes it can be hard to choose what we are going to like. There are a lot of coffee flavor & aroma subtleties that are lost on me. But thanks to buying enough coffee that just didn't work for me, I have settled on a few personal guidelines- If it doesn't say something about "chocolate", I probably won't bother If the notes suggest a light roast, I won't bother If it makes reference to tea flavors, it will probably be lost on me, so I won't bother The obsession with chocolate flavors (I'm talking dark chocolate here, not the too-sweet version that comes from Hershey's) is kind of a negative interpretation stemming from disappointment with cof...

The Aillio Bullet I use to roast coffee has a few features that help make those of limited skill (that would be me!) appear to be smarter than they are. As I mentioned before, the 4 determining sensory inputs that guide the roast are sound (1C and 2C), sight (mostly color), smell (which can be illusory) and temperature. One of the reasons I wanted to buy the Bullet is that it has what I think is a good temperature measuring system. The Bullet provides... Bean Temperature from a thermocouple Drum Temperature from an infrared sensor Bean Temp (smooth green line at left) originates from a thermocouple probe located in what the designer hopes is the center of the bean mass as the beans tumble inside the drum. The user can defeat that carefully chosen geometric location simply by choosing a different batch size than what was intended. As a user I don't know if my typical batch size of 550 gm of green beans causes any errors or not, but being consistent from batch to batch should cancel...

Outdoors! To paraphrase Mark Twain's Connecticut Yankee in King Arthur's Court : there's more than one way to skin this cat. A few ways of roasting that come to mind are to roast the green beans... over a fire in an iron skillet (remember Dances With Wolves?) in a hand cranked popcorn popper on your stove in a hot air pop corn popper in a purpose-built hot air roaster (called a fluid bed roaster) in a purpose-built and sophisticated gas fired drum roaster or a simpler version like a BBQ mounted drum on a spit in a purpose-built electrically-heated drum roaster , either inductive or radiated in a flour sifter with a heat gun (yes, I'm serious!) and, according to Thompson Owen of Sweet Maria's, you can even use a gas fired oven or a last resort, with a heat gun and a dog bowl ! Flour sifter roaster What won't work is a microwave or anything that involves water directly. And roasting in your oven will get it done but (as linked above) the likelihood of a good t...