My First Home Coffee Roast

I recently watched a recorded talk given by Asher Yaron on fresh roasted coffee:

I admit that I was absolutely floored by the bold claims that Asher Yaron made in his presentation. I’ve owned an Aerobie Aeropress (~$25, for the past year and a half, and I’ve been happily pressing cups of coffee daily since. I had to investigate for myself whether fresh roasted coffee would make a difference.

At the time, I was nearing completion of yet another bag of Starbucks whole coffee beans. Soon I would be due for a re-up. A couple of weeks ago, I took a visit to Java Coffee & Tea Co. (2727 Fondren Rd, Houston, TX 77063) to discover what I might find in store.

I explained to the man behind the counter that I’d heard some wonderful things about fresh roasted coffee, and that I’d found Java Coffee & Tea Co. after a cursory search for a local coffee roaster. I asked him for the freshest roasted coffee that they had available – he advised that the Costa Rican “La Minita” Tarrazu fit the bill. I picked up a half pound of this, as well as a quarter pound of green Tanzanian Peaberry, and immediately set out to try the fresh roasted La Minita.

I finished the La Minita a couple of days ago. Eager now to try my hand at home roasting, I read up on the skillet roasting method at

I used a copper wok that I have at home, working under the assumption that copper’s even heating properties would be of some value in this enterprise. The Polder digital in-oven thermometer (~$30, that I had at hand only measures up to 392˚F, significantly shy of the 500˚F air temperature that I saw mentioned on Sweet Maria’s. I measured out four scoops of Peaberry and started the roasting process.

I didn’t time myself, but I listened for the “cracks”. The Peaberry is meant to roll easily, making it a good candidate for skillet roasting. It’s possible that I didn’t roast the coffee to the second crack. There was also chaff remaining on a significant number of beans. I observed that they took longer to grind than I am accustomed to. I brewed myself a cup shortly afterwards and noted that the flavor was.. green?

The results of this first roast could have been better, but it was a fun learning experience, and I’m prepared to take another crack at it. Update to follow.

In response to a young student

Hello, I saw your Engineering notes and I am thoroughly fascinated. Woah man, those problems involving porosity in rocks seem so alien and complicated. Are you a genius? How does one even understand and pursue this field? It appears to be very rigorous and math intensive. As a young student, do you have any advice for me sir? What discipline do I choose sir? Also, we are both (redacted) I noticed! Fascinating.

(message dated Sunday, August 10, 2014)

I’m really glad that you wrote, and I hope that you won’t feel offended if I post your letter in a more public forum. I desire to share my thoughts more broadly, so please understand my decision in responding to you here. Additionally, I thank you for your patience in awaiting my response: I am probably the biggest wash-up out of all the petroleum engineering graduates that I know of (the only one in my graduating class to not land a full-time position in my field of study!), but that doesn’t excuse me from writing a half-hearted letter.

I am no genius, though I have always been a strong test taker. This ability to gloss through materials and to quickly commit the necessary parts to memory has served me well, though it has gained me unwanted attention in the past. There is an incident that stands out in particular.

During my time at the International School of Kuala Lumpur, I dedicated two years to the pursuit of the International Baccalaureate. This course of study requires initiates to select three courses to take at a standard level, and three at a higher level. I won’t bore you with the details, though you may read up about the IB Diploma on Wikipedia if you wish. I had not decided on a particular career for myself, but I knew that I was drawn towards the sciences. I took both Physics and Chemistry at the higher level.

There were two sections of IB Higher Level Physics: I was enrolled in a section of IBHL Physics with some friends who’d taken on a couple of new students into their group. One of the new students was in the other section of IBHL Physics, and he managed to sneak out a copy of a pop quiz to be held later in the day. I happened to find them circulating this quiz amongst themselves during the lunch hour, and I was miffed that they hadn’t included me. Before our section of Physics started, I went to class before anyone else, where I approached the teacher and let him know that some members of the class had prior knowledge of the quiz.

The teacher took this in stride and changed the quiz question for our section, announcing this on the whiteboard. The modification tripped up the would-be cheaters. Confounded by the change, they were subsequently caught because their answers didn’t reflect the new circumstances.

Afterwards, my friend approached me and confronted me for turning him and his comrades in. He and I took an introductory Chemistry class together in the previous year, and I used to help him study. He accused me of telling on them. I told him that I hadn’t given the teacher any information on who had gotten advance knowledge of the pop quiz, but he didn’t believe me. When asked why they’d tried to cheat, he said, “You study for just a few minutes, and you are able to get 100% on the tests. Some of us have to spend hours, and we don’t get the same result.”

After this incident, I was further alienated from their group. They felt that I wasn’t trustworthy. Worse yet, they had me pinned for a rat.

What can you learn from this situation as a potential student of the hard sciences?

Any problems that appear alien to you now can be understood through careful study. There is no way around this. The good news is this: the more experience that you have dealing with problems, the sharper your intuition come the end result. Developing your intuition is essential, because it can alert you to problems that you made along the way to the solution. This is also why it is of paramount importance to show every step that you take towards a possible solution.

Any engineering discipline will require a solid grasp of mathematics, but don’t be deterred by this alone. I was never a strong mathematician, as evidenced by the great difficulty that I faced in IBHL Math and in my college Calculus III class. Yet I was able to complete the bulk of my undergraduate petroleum engineering courses without a problem.

The truth is that most engineering problems (at least in school) do not hinge upon a very strong understanding of mathematics. You can see it in the formulae used to arrive at the solutions that you see in the vast majority of my petroleum engineering notes. Very rarely did we have to rely on our knowledge of calculus to present a test solution. Oftentimes, a strong grasp of algebra was sufficient. The calculus and differential equations came into play as we copied down derivations from the professor’s notes.

The situation is very different if one attempts to pursue an advanced degree. I had the opportunity to audit Dr. Ovadia Shoham’s Two Phase Flow Modeling course during my junior year of college. The mastery of mathematics required there was on an entirely different plane from that needed in my regularly scheduled classes.

To answer your questions on how one chooses petroleum engineering and how you can best go about choosing your discipline of study, I provide a brief introduction to my personal choice, and thoughts on how to narrow the field. Petroleum engineering at the University of Tulsa felt like a natural fit for me because:

  1. I was born in Tulsa
  2. My father had made a successful career for himself as a graduate of the University of Tulsa

When I finished high school, I had two attractive college options. I could commit to either the Electrical Engineering program at the University of Texas at Austin or the Petroleum Engineering program at the University of Tulsa. I reasoned that the field of electrical engineering, being closely linked to computers, might evolve too quickly. Both of my father’s brothers hold Bachelor’s of Science in electrical engineering, and I balked at the large number of computer texts that my xiao shushu (“little uncle”) maintained on his bookshelf. It seemed that the rapid pace at which computers evolved would necessitate more study than I cared to sign up for at the age of 18.

My little uncle’s career had taken some twists and turns throughout the time that I’d cared to know about it. My big uncle went back to school to earn his MBA, and he pivoted out of engineering altogether. By comparison, my father’s career was luminous. I knew from the time that I was five that being a petroleum engineer could translate into international assignments in the world’s major metropolitan centers.

Finally, I decided that I would go back to Tulsa on merit of the fact that I had a history with that city. I was born there, left at the age of two, and had only gone back on a couple of occasions. It felt like the right thing to do: a true homecoming, and an opportunity to forge my own path as a world citizen upon graduation. It helped that the University of Tulsa was offering me substantial scholarships to study there, and that they waived enough credit hours for me to earn my degree in three and a half years. Furthermore, petroleum engineering ranks amongst the best undergraduate degrees for return on tuition and time invested. Few other fields, outside of computer science, will see young graduates entering the working world to salaries of $80K USD.

I recognize that my situation may have been more loaded than the one that you will face, so consider these fundamental questions:

  1. What do you like to do?
  2. What are you good at?
  3. What will people pay you to do?

(Borrowed loosely from Alan Watts, amongst others)

All three are important, though the last one is a controversial one. Money should not be your prime motivation for pursuing anything: it is an unstable foundation upon which to build a career. The truth is that one needs very little money in order to enjoy a good life. It is of far greater importance to focus on building a system that will have you waking up, eager to approach each new day. That being said, even the best budget can’t correct for insufficient income.

In my studies at the University of Tulsa, I quickly found that I was a minority. Few of my peers had any tangential link to the oil and gas industry. I learned that most of the international students who were there on scholarship were given these opportunities because they had excelled in their studies. The oil and gas industry is important to every nation on this planet, so national oil companies pick from the brightest scholars to sponsor. I held great respect for those who were lending their minds to the development of their home countries.

Untold scores of young people will choose a field like petroleum engineering because it offers the potential to make bank. Can you imagine how grueling it is to go to class when this is your prime motivation?

My background and desire to apply myself in the engineering discipline helped ease my tortuous journey through my college years. When asked by recruiters why I had chosen to pursue petroleum engineering, I sometimes leaned too heavily on the extrinsic benefits of being a petroleum engineering that I mentioned earlier: the generous salary and opportunities to work across the globe. At my most honest, I would tell them that I wanted to work on major projects that would impact many scores of people. Why be a doctor and touch the lives of a few when you can work as a petroleum engineer and power every aspect of modern industry?

I believe that the best engineers are the ones who really want to contribute in a meaningful way to the world. I wanted to work with the best and brightest minds and to see the fruits of my labor stand the test of time. It would never be enough to leave behind a pretty headstone as my only lasting legacy. I wanted my work to power cities, to literally grease the machinery of global commerce.

Don’t choose something unless you can really, truly grok it.

There are two things that I want to leave you with, if nothing else. The first is a favorite saying of Dr. Frank S. Manning, a long-time professor at the University of Tulsa (50+ years!), who taught Thermodynamics to both me and my mother:

Anyone can be an engineer. You just have to know how to read.

Secondly, believe in yourself and in your ability to do good in the world. You must commit yourself to success in your chosen field of study. I risk sounding trite here: it will not be easy, but you can truly accomplish anything that you set your mind upon.

Alex Zheng

Minor edits made post-publication, courtesy of the learned Justin Zheng

SFF (Mini-ITX) NAS Build using Intel Avoton

While searching for parts and ideas for my FreeNAS build, I came across Intel Avoton. Per Intel’s page on Avoton:

Intel® Atom™ Processor C2000 product Family (codenamed Avoton and Rangeley) is the next generation System-On-Chip (SoC) built on Intel’s 22-nanometer process technology. This highly-integrated SoC contains up to 8 64-bit Intel® Atom™ processor cores …

Okay, so far so good.

These SoCs were created to address the needs of the Microserver, Entry Communication Infrastructure and Cloud Storage markets

Perfect! This sounds like it fits the bill perfectly for a low-powered NAS build.

I was drawn by just how little power the Intel Avoton family of chips needs. To give you an example, the most powerful chip of the Avoton family, the C2750, is rated for a max TDP of a paltry 20W. I’ve reproduced the table from the Intel Avoton page below:

Product Name Launch Date # of Cores Max TDP Recommended Customer Price
Intel® Atom™ Processor C2750
(4M Cache, 2.40 GHz)
Q3’13 8 20 W TRAY: $171.00
Intel® Atom™ Processor C2730
(4M Cache, 1.70 GHz)
Q3’13 8 12 W TRAY: $150.00
Intel® Atom™ Processor C2550
(2M Cache, 2.40 GHz)
Q3’13 4 14 W TRAY: $86.00
Intel® Atom™ Processor C2530
(2M Cache, 1.70 GHz)
Q3’13 4 9 W TRAY: $70.00
Intel® Atom™ Processor C2350
(1M Cache, 1.70 GHz)
Q3’13 2 6 W TRAY: $43.00

Motherboard + CPU: The Intel Avoton family of processors are available as SoC. One should make a selection of processor based on the NAS’s anticipated workload. At the time of writing, the C2750 is available with boards from Supermicro starting at $377 USD.

These products would pair nicely with Silverstone’s DS380B and that company’s fully modular 450W SFX PSU.

Case: Silverstone Tek DS380B Mini-ITX Small Form Factor NAS Computer Case, Black (Amazon)

The Silverstone DS380B is pretty unique – it provides users building on the Mini-ITX platform with a SFF box that features support for up to 12 drives: 8 hot-swappable 3.5″ or 2.5″ SAS/SATA and 4 fixed 2.5″ drives. It has earned strong reviews from a litany of hardware review sites.

PSU: Silverstone Tek 450-Watt SFX Full Modular Power Supply, 80 Plus Gold ST45SF-G (Amazon)

I like that Silverstone put out a fully modular PSU because space is at a premium in any SFF build. The ST45SF-G’s 80 Plus Gold certification doesn’t hurt, either.

I am confident that these parts will result in a very compact, quiet, and energy-efficient NAS that will cover basic needs. The cost of a SFF NAS will exceed that of a comparable, larger machine, but the smaller footprint does lead to interesting possibilities.