Random Musings of a Coffee Technologist

Hey Neal- I have a new 2.5k Diedrich we are working with and I guess it is normal, according to Diedrich, to hit full gas at only half way with the knob- so only half of it is utilized- and actually it only is really adjustable about 40% of the rotation- sooo...just curious if you have noticed this, I would think I could change out the knob with a different resistance to utilize the full rotation? Any advice appreciated ;)

Thu, 23 May 2013 21:50:39 -0500

That doesn’t sound normal to me and mine aren’t like that. My advice would be that if you’re planning to swap out parts, make damn sure you know what you’re doing so you don’t either break the machine or create a safety issue.

Roasting for Espresso

Thu, 23 May 2013 14:03:25 -0500

Today I got an email asking for my thoughts on roasting for espresso and I thought that readers here might be interested in my approach to that. This is most of my reply in which I largely don’t answer the question.

—

It’s very rare that I will roast anything specifically for use as espresso. That isn’t to say that you might not want to do something different when roasting for espresso compared with other extraction methods or that there isn’t a benefit to having a different approach for espresso. Rather, it’s an honest admission that it tends not to be required to get what I’m looking for in an espresso blend (I’ve had a few good single origin shots but that’s not what I’m interested in selling at the moment) from the sorts of product mix I tend to have available to work with. YMMV. Instead, I’m looking at how the coffee performs on the cupping table and following up with verification by drip brewing when I develop my roast profiles. Then when I need to update my espresso blend I will try the coffees that I have to work with individually as espresso and then start mixing things and again trying as espresso until I have something that matches the flavor profile that I’m looking for. Rarely that doesn’t work and I need to think about either custom roasting some component of the blend just for use in espresso (which is annoying since I also like to use fresh coffee as espresso) or blending before roasting (which solves the freshness issue but has its own limitations) or sometimes a combination of the two (which gives the worst of both worlds from a management perspective but taste trumps ease of production).

When I think about espresso, it is something that I can enjoy drinking every day. I want something that is intensely flavorful, something with a complex flavor profile, something that is slightly sweet without being astringent, and something that is well balanced. The only thing that’s a bit vague there is complexity. Properly prepared espresso has a very low surface tension which means that it will get deep into the tongue as you drink it and unless you wash your mouth out you can still taste the espresso up to two hours after drinking it. I’m looking for something that continues to be interesting throughout that time. It seems that this sort of flavor profile also always does well in milk drinks. I’ve tasted some espresso blends that were designed with a milder flavor to appeal to a broader audience where my feedback has been that even in an 8 ounce double cappuccino I could no longer taste the coffee. Similarly, there are some who eschew balance with mixed results in the presence of milk. There are markets for both approaches but neither is what I’m interested in selling.

To achieve this I tend to use a blend consisting of coffees that range in degree of roast from just into the second crack through a French roast and using coffees from the Americas and the Pacific islands. Rarely an African. Never any robusta. Almost always 10-20% coffee from Papua New Guinea. Nothing in a proportion of less than 10%, usually 4 or 5 ingredients, but sometimes 3 or 6. At present it’s 50% Guatemalan, 20% East Timor, 20% Java, 10% Papua New Guinea, which is a bit atypical for the lack of a Brazilian coffee. All of those are washed coffees, but I’ve used non-washed coffees in the past. There again, espresso was not something that I was thinking about when deciding how to roast those.

If there is any advice that I would give on roasting for espresso, it is to evaluate your roasts as espresso (I would suggest that cupping has no place in espresso development) to build up experience that you can call on when you’re having trouble getting what you want out of the coffee you have. Beyond that, you may get some very different answers if you know any roasters in coffee producing areas that are developing markets for specialty coffee consumption. Almost all of these seem to be focusing primarily on espresso at the moment and have unique constraints in that they are not able to import coffees from other countries. So, for example, if you meet a roaster from Brazil you may want to ask them the same question.

Photo

Thu, 23 May 2013 09:15:01 -0500

There’s a webcam pointed at this intersection and this...

Tue, 21 May 2013 21:35:24 -0500

There’s a webcam pointed at this intersection and this very nearly happens to tourists doing this with some frequency.

Twitter can be odd sometimes. While I do believe that a proper...

Mon, 20 May 2013 11:19:29 -0500

Twitter can be odd sometimes.

While I do believe that a proper interpretation of the 2nd amendment grants every American the right to own and arm a fighter jet and as nice as it would be to deal with the FAA instead of the TSA, I did not buy a fighter jet. I also did not go with a vintage motorcycle.

I got a lightly used grey Kia Soul. If I could only pick one adjective to describe it, I would say it’s boring. Acceptable fuel economy, good price, handles well enough, enough space in back to transport the occasional book shelf, arcade cabinet, or coffee lab.

How cat girls are made.

Mon, 20 May 2013 06:05:23 -0500

How cat girls are made.

jacquiracquel: I need this in my life forever.

Sat, 18 May 2013 17:20:20 -0500

jacquiracquel:

I need this in my life forever.

So it’s 100% fat then?

Tue, 14 May 2013 09:35:57 -0500

So it’s 100% fat then?

Photo

Mon, 13 May 2013 21:11:20 -0500

dreadtroll: maebird-melody: paragonpostcards: Literally the...

Mon, 13 May 2013 14:35:57 -0500

dreadtroll:

maebird-melody:

paragonpostcards:

Literally the American employment system.

Seriously! I’m not the only one who’s had this problem!

best buy, toys R us…

i actually WANT to help customers and do a great job because i take jobs seriously

none of your current employees are even trying

are you really sure that i’m unqualified??

I generally (there are exceptions) prefer to hire people without prior barista experience. That way I don’t have to get them to un-learn all the wrong stuff their previous trainer taught them in addition to training them to do things right.

hanniballecters: “Friendship, knitting, ….murder” omg

Fri, 10 May 2013 08:12:47 -0500

hanniballecters:

“Friendship, knitting, ….murder”

omg

Touhou x Utena

Wed, 08 May 2013 22:00:16 -0500

Touhou x Utena

derpycats: gpoy when I try to smile for a picture. That cat...

Wed, 08 May 2013 11:36:24 -0500

derpycats:

gpoy when I try to smile for a picture.

That cat has a lot of fish pictures.

hey neal, been wanting to set up a logging system for my diedrich ir-3. saw several of your videos and am looking forward to using typica. basically all of my questions are in this unanswered thread on coffeeforums/roasters where should i add thermocouples, di-145 support working? and is it worth adding 2 thermos instead of using the existing one. thanks! brian

Tue, 07 May 2013 12:32:10 -0500

I’m not sure what thread you’re referring to (is tumblr still not allowing links in asks?) but if I miss something and you want to do a follow up, shoot me an email.

DI-145 support: Working in the development branch on github, I’m using this myself now, will be in 1.6 (real soon now) with in-program configuration and channel calibration. Currently that support is Windows only. Should work with everything from XP through 8. Want to get it going on Mac/Linux as well but that won’t be done for the 1.6 release. I intend to put together a video before this goes out that covers how I have my IR-1 set up with that hardware which you might find informative.

Thermocouple placement: You should already have one placed appropriately for bean temperature and if you’re asking about the DI-145 I’m guessing you intend to just use the port on the roaster. That’s what I would recommend. On an IR-3, particularly now that Typica supports rate of temperature change data I probably would not bother adding the second thermocouple, but if you did the best place would be near the top of the drum, central, far enough away from the edge that moving parts aren’t going to bang into it but close enough to it that it won’t be covered in coffee beans except perhaps as the batch is first falling into the drum. Note that if you want a secondary thermocouple logged you’ll need either another data acquisition device to hook that into or another signal conditioner to amplify and linearize the signal if you want to hook it into an unused channel on the DI-145. To install that you’ll also want access to a drill press, an appropriately sized cobalt drill bit, and a tap wrench with tap appropriate for the threads on your mounting hardware.

I really need to do something better with data series color...

Tue, 07 May 2013 07:31:17 -0500

I really need to do something better with data series color selection.

The timing on introducing the rate of temperature change monitoring feature in Typica’s development branch was good. New coffees recently arrived so these have this information in their target profiles. I’m saving new target profiles for the rest of the coffees as I get to them and most of those now also have that data (I don’t want to auto-generate the data). Now that these new profiles are turning up and I’m using the extra information to better match roast profiles I can say that I’ll recommend turning this feature on. Note in particular the slow section at first crack. This was really easy to maintain a match on and around and combined with the profile translation feature (3 seconds in this case) I expect our already low inter-batch variation on QA metrics to get even lower. The use is similar to using air temperature monitoring to better gauge control adjustments but easier since it nicely abstracts out differences in batch size and retained heat. Thanks all who requested the feature. It’s more useful than I expected.

I still have a few other areas where I want to polish things a bit more before the 1.6 release, but that should be happening very soon. I’m also hoping that I’ll be able to get some time in to assemble a couple videos, in particular one going over how I have all of the new stuff set up at the lab roaster, but there again I’m not going to hold the release up for something like that.

Magical scout has a very low luck stat.

Tue, 07 May 2013 06:18:14 -0500

Magical scout has a very low luck stat.

Finally got my back log queued.

Tue, 07 May 2013 06:16:27 -0500

Finally got my back log queued.

I seem to have landed on this part of YouTube again.

Sat, 04 May 2013 20:50:04 -0500

I seem to have landed on this part of YouTube again.

Cost of Green for Roasted Coffee Reporting

Sat, 04 May 2013 08:41:02 -0500

Today I spent some time working on a new report for Typica. This one calculates the cost of green coffee per unit of roasted coffee. Implementation is simple. First it acquires a list of the roasted coffee items you currently produce. This is the same as the list of roasted coffee items in the New Batch window so if you’ve been keeping that current there’s no extra data entry that needs to be done for this. If you haven’t been keeping that current you’ll just have some extra data in the report.

With that list of roasted coffees it then determines what proportion of which green coffees are used to produce that roasted coffee. In most cases this will be 1 green coffee that makes up 100% of the roasted coffee, but since Typica supports pre-roast blending the report needs to handle that. This set of current recipes is based on the most recent roast of each roasted coffee item.

Next we want to get some aggregate information on all batches of a particular roasted coffee item using a particular set of green coffees. Specifically, we want to calculate the minimum, maximum, and mean of the expression 1 / (-1 * ((G - R) / G) - 1) where G is the weight of green coffee and R is the weight of roasted coffee. That expression gets you how much green coffee is needed for 1 pound of roasted coffee. We limit that to batches where G > 0, R > 0, and the batch was approved. These aggregates are then multiplied by the sum of the proportional costs of the green coffees used to produce for each coffee a set of numbers that can be used to estimate the cost of green coffee for each current roasted coffee item. Generally you’ll want the mean value (median would be better and more reliable but I don’t think PostgreSQL has that built in, I might have Typica add a user defined aggregate function for that in a future release as that’s not hard to add), but the minimum and maximum are provided so that it’s easier to see if there’s something weird in the data that might throw that calculation off.

Note that this doesn’t attempt to capture all of the costs associated with roasted coffee production. It doesn’t capture fuel costs, electricity costs, labor costs, packaging costs, any fees such are warehousing or freight costs that are separate line items from the green coffee, or any kind of general overhead costs. All this captures is the cost of green coffee and weight loss for each of your roasted coffee items.

The report needs a little more clean up (I wanted to make sure that it worked properly before adding more features so right now it only reports cost per pound and it needs to also be able to report cost per kilogram if that is your preference and the ability to sort on anything other than the name of the roasted coffee item would also be nice) but it doesn’t currently make use of any features that are not already in the latest release version of Typica so if you want it early you can grab the file from github (look for the Raw button to get a file you can save), drop it in your reports folder, and start using that now.

I mentioned this yesterday, here it is with a date and time.

Fri, 03 May 2013 10:20:36 -0500

I mentioned this yesterday, here it is with a date and time.