When Specialty Coffee Isn't Appropriate?

For the past two weeks, I've been on a home-coming journey to the small, cigar-shaped island of Yapen in eastern Indonesia. The trip was a personal and community milestone packed with celebrations. My siblings and I were formally inducted into our tribe, reunited with long-lost friends, and joined the villages in celebrating the publication of the first book in their language, a translation of the New Testament completed by one of their own people.

This was all wonderful, but what stood out from a coffee point of view was very different. The island of Yapen is on the low side for growing specialty coffee, topping out at a little over 4,000 feet (1,200 meters). Most coffee is grown in individual plots along a single mountain valley in the lower 3,000's (900+ meters). The varietal is untested, but was introduced from Brazil in the first half of the 20th century by Dutch colonizers. I suspect the trees are robusta-arabica hybrids.

The community does a great job with managing their value chain. Crops are grown individually and then sold (either dried or wet) to the local cooperative, which owns depulping, hulling, drying, roasting and grinding equipment. The cooperative processes the coffee, packages it and sells it on the regional market under it's own brand for about $1 a pound. This is a sustainable business and price point, and the cooperative has been running for decades now without provoking either a spiral of deforestation or going bankrupt. In fact, the cooperative has amassed significant savings available for re-investment into community infrastructure projects.

Great stuff, and my first thought was that simply by changing out their coffee varietal, the community could move up market and capture disproportionate returns in the specialty market. Maybe. I think community vision and entrepreneurial willingness are definitely present, and the small family holdings of coffee would lend themselves to gradual, low-risk adoption of new coffee trees and processing methods as families observed a few innovators.

The challenge, I think, is the topography, soil and disease burden of the area. This is not an easy place to grow coffee. The current coffee stands are mature and are being replaced gradually, but they suffer from (I suspect) coffee borer disease as well as a fungal infection. Proper diagnosis and treatment of coffee stands is extremely difficult, as coffee stands are spread out in clumps over difficult terrain far from a qualified agricultural specialist.

Topsoil quality also seems to be a challenge. Without active cultivation, the soil is extremely clayey and apt to slide down the steep valley walls at first opportunity. In fact, a recent earthquake left fresh scars in the rainforest hundreds of feet across all over the island and obliterated the village's only road.

Bottom line, while there's plenty of energy and interest in expanding coffee opportunities responsibly, the low altitude, unstable soil and disease prevalence form a very tough triad that has me stumped in terms of an appropriate varietal.

Any thoughts? I loved getting a chance to see coffee and the dedication of a proud group of coffee farmers! I know they'd do their best with a better coffee varietal if one was found.

Photos courtesy of Ethan Johnson.

Landslide - where's the road?

Wet Depulper

Even the village is built on a steep slope!

Introducing (Properly) the K250 for AeroPress

One of the joys and challenges of working with a small business is that everything needs doing at once. One of those things that has needed doing for a long time has been proper introductory videos to each of our products. Without further ado, here is the first of these, a brief introduction to our K250 filter for AeroPress.



Yes, this film shows an inverted brew method. The K250 filter actually works fine with both inverted and traditional brew methods, but we decided to show the inverted because it's our favorite! :)

- Nate

P.S. Thanks to Velton again for the Colombia Camilio Torres used in the making of this film. Thanks to our AeroPress brew session, we caught a lot of the coffee's sweet complexity that we weren't getting any other way.

The K250 sealed in

...and at rest

On Constructing a Brew Chart

How do you make a brew chart for a brew method that hasn't existed before? After all, I'm still trying to understand exactly how the double catcher press brews. I'm still getting spotty results. Some brews are great, and others are unremarkable -- and I don't always know why!

This evening, thanks to a good conversation with Velton Ross of Velton's Coffees, I finally feel like I can describe and understand the critical instruments that can guide me across this uncharted terrain. What are they? First: proper brew temps and second: proper grind / dose / time ratio. Coffee extraction isn't magical, and while double catcher extraction processes are still unexplored, thankfully the fundamentals of extraction are established.

It all crystallized for me tonight as I watched the same roast of Honduras blossom over the course of three brews. Velton's outside perspective popped the problem open after each of the first two cups, getting my mind out of it's rut of assumptions and encouraging me to look at some other variables in the cup that I'd dismissed.

What changed? Cup 1 tasted under-extracted, like tea, while the coffee catcher bed exploded with aromatics that were not extracting into the cup. I pushed the grind 3 notches finer and tried again. This time the cup was much more thoroughly extracted - but it lacked the acidity, fruit and florals that had emerged on the cupping table. Velton suggested upping the brew temp, observing that the bloom-free water was likely way below brewing temps when the top catcher was pulled at 3 minutes and full brewing began.

He was right. For cup 3, I tried pouring directly from the boiling kettle and gauging my water temp each minute. The temperature really dropped off, even with boiling water to start the brew. For cup 3 I measured 198, 190, 188 and 180 at minutes 1-4, respectively. The dramatic drop on minute 4 happened almost instantaneously as I pulled the top coffee catcher and released the coffee fully into the water.

Regardless, near-proper temps made a huge difference. The bright florals and fruit jumped out of the cup. There was an enticing fizziness, a carbonated "pop" to the cup that I'd observed in previous delicious double catcher extractions. The body and middle / dark notes were still solid, though not as well-developed as they could have been. The extraction was still slightly watery, so I know I have more dialing in work ahead of me. As I start to track fundamentals, though, that's actually just what I'd expect, as I know my brew temp is still considerably below the 195-205 that I want to hit throughout the 4 minute brew process.

I realize finding a method of achieving correct brew temp in the French press is going to be tough. In fact, I know a lot of my barista friends who haven't figured it out with a traditional press method either. I'm convinced it can be done. Specifically, I'm convinced there's a way to bump the initial temp up 7 degrees to 205 and way to block the massive heat exchange during the third minute coffee catcher pull.

What did I learn tonight? Brew fundamentals stay the same, regardless of the novelty of the brew method. Nailing down my temperature will allow me to drop my dose and tweak my grind to the actual range for double catcher extractions. I feel like I have a compass I can use to dial in my double catchers - and to check my pour over and espresso and siphon too.

It's good to get back to basics.

Notice the clean press and the pulled bed, both key features of the method.

- Nate

195 in the Slurry!

As a good barista will tell you, it's freaking hard to hit proper brewing temps in a pour over slurry. Heat loss from the kettle, the dripper itself and the open-air bed combine for far less than ideal brewing temperatures. We tend to compensate for this with higher doses of coffee, but that really only disguises the problem.

Cole McBride went back to basics and eventually devised a hot plate-enabled pour over process that does consistently hit 195-200F in the slurry. He found he used less coffee to yield a more balanced and flavorful cup.

I thoroughly enjoyed both his presentation and the resulting drink. Check out the video below:

Questions? Comments? Get in touch with Cole through his twitter or with me below.

- Nate

Coffee: Sustainability Enacted?

I hear a lot about sustainability in the coffee industry, and much of that conversation is focused on negatives -- what we, collectively, aren't yet doing well. But I want to suggest that many of us already extend to our customers a profound and subtle invitation to sustainability simply by doing what we do.

Frankly, I get tired, worn down and mentally numb from hearing all the things I'm not supposed to do or buy or be because they aren't sustainable. Do I care? Yes, passionately, and that's exactly why I'm a victim of sustainability information overload. I think many of our customers, to varying degrees, feel the same way about the issue. Sustainability has become a buzzword, not only devoid of clear meaning, but ignored because it is over-used and usually associated with negatives -- green Thou Shalt Not's.

Here's where we can break through the clutter. Great coffee is not about what you don't get -- it's emphatically about what you do get. More importantly, a great coffee experience goes beyond the whole getting, consuming thing and offers customers a chance to stop buying for a moment and start savoring, enjoying and exploring again. Sustainability, I suspect, is ultimately about quality.

As rich westerners, it's about learning to value quality of experience, quality of life, quality of workmanship over quantity of stuff. As consumers, it's about realizing that quality experiences demand us to engage honestly with our baristas, and with those who stand behind them in the value chain as if we all had something to offer and something to gain from a great cup of coffee.

It's not about more information, really, because I will never know enough to be sure that the coffee I get is completely "sustainable," let alone the t-shirt I wear, my carpet, or broccoli. The problem with making sustainability mostly about more information is that I as a consumer (or as a coffee professional) already have too much information in my life.

What I need, and what I think most of us lack, is trust. Trust is the relational currency that backs a local cafe's rock solid standing with it's regulars. Trust calls me to value another person's opinion, effort and ideas because of who they are, not because I can check every single thing they do. This doesn't mean that information isn't important, it simply means that information transparency only really functions as it should within an atmosphere of trust.

I could say a lot more on this, but really all I want are more coffee experiences where I'm invited to have a cup of wonderful coffee and conversation and fewer coffees that come with their own sustainability mini-sermon. Thankfully, many of us do a good job at this already, and I think our very ability to offer a customer a chance to be a real human being for 10 minutes instead of a consuming automaton is a powerful act that gets at the very heart of "sustainability."

A coffee farmer's hand in eastern Indonesia, near where I grew up.

18:22!? - The Ironies of Coffee's "Magic Window"

Every coffee lover ought to be familiar with the magic window for coffee: 18-22% of extracted solids are considered the optimum ratios to produce a good cup. Now, this range comes loaded with as many caveats as there are baristas.

While everyone has their own take on the flaws and benefits of the "magic window," I thought I'd scribble down a few of the more confusing ironies that come with having a widely acknowledged but rarely followed industry quality standard.

1. It's really a fuzzy continuum, not a range per se. The range is based on aggregated taste preferences, and the survey itself has not been updated in years (decades?). In other words, the window represents the average preference of the tested coffee drinkers when the survey was conducted. Frankly, it may or may not have any relationship to your preference, and as such it's claim to be normative quality standard (i.e. you "should" brew this way) will always be somewhat shaky.

Here's the really interesting part about that: coffee drinkers seem to prefer different extraction ratios for different coffees and brew methods. Coffee lovers who relish their French press of Sumatra every day may well prefer a technically over-extracted cup, because that's what a good press of Sumatra tastes like to them. Those same drinkers, though, may prefer espresso to be properly extracted. In other words, in the real world context influences our taste perceptions far more than we coffee nerds would like to admit. This alone, I think, should give those of us who work in coffee a degree of humility when assessing the quality of a particular coffee bar. Are they serving to the taste of their customers? Recommendations for increasing coffee deliciousness should proceed with that in mind.

2. The 18:22 window can't describe evenness of extraction, a point ably brought to my attention by James Hoffman. In other words, you may get 20%, but there's no guarantee you're not pulling 24% at the top of the brew and 16% at the bottom, which would likely not be tasty. I've noticed this point myself when experimenting with innovative French press techniques, as I try to avoid problems of uneven extraction problems using a traditional wait-and-press method. Evennness matters because uneven extraction yields a partial picture of the coffee. You're missing some of the taste symphony in your mouth.

3. Some beloved brew methods rarely hit the window. I'm thinking particularly of French press and cold brew here. For the press, the lengthy rectangular brewing chamber coupled with a traditionally coarse grind, lots of bloom and long immersion time yields a wide disparity of coffee concentration from top to bottom of the brew chamber. The resulting brew is loaded with fines and starts with a hint of bitterness that only grows with time. Yet, those coarse particles don't fully extract, as anyone who has compared a cupping table with a French press will attest. Traditionally prepared presses are just not good at bringing out a coffee's delicate notes.

Cold brew actually under-extracts, despite it's reputation for fierce caffeine content. Again, while the cold temps are known for not generating acidity during brewing, they also fail to fully extract the flavors associated with that acidity - that popping green tomato in some Kenyas will fall flat in a cold brew every time. Don't get me wrong, I love a cool tankard of iced in the summer, but I know I'm deliberately trading out nuance for the coffee equivalent of smooth power.

These two brew methods are not the only serial offenders when it comes to routine over or under-extraction. The difference is that many of us seem to enjoy these brew methods prepared this way, whilst there seems to be less patience for an over-extracted shot or a sour, under-extracted pour over.

4. Finally, the window is not equally delicious. As a (very) general rule, it would be ideal to extract a coffee as close to 22% as possible without going over. The problem is that the exact "red line" will vary slightly by coffee (by bean!) and this slight natural variation coupled with the human challenge of brewing consistently yields an exponential rise in risk as a brew approaches 22%. While widespread measurement of extraction percentage remains elusive (another discussion), I think one of the marks of a good barista is his or her ability to walk that line, crafting a great brew that holds as much of the coffee's flavor as possible - without tipping over into bitterness.

Thoughts?

Fragmented tasting preferences: who says your cup tastes good?

Pour Over Spirographs

Just in time for the communal talkathon that is SCAA, we're posting Charity's distinctive spirograph pour over technique. It's named after the path your spout traces, kind of like overlapping slinky circles.

Is it consistent without a timer? She seems to think so. Commercial outfits will likely beg to differ when it comes to clocking pours, but tasty results with fewer tools gets my (biased) vote for home brews.

Thoughts?

Learning Humility with Customers

Some customers are more coffee fuelers than lovers. They may stop in for a quick latte, but they're likely to demand a 16 oz one in a paper cup. While excellent shops can begin to convert these caffeine addicts into connoisseurs over time, it's a tough sell!

You'd think coffee lovers, by contrast, would be the ones we'd love to serve. Not so, at least in my experience. Quite honestly I think they may be harder for us to appreciate and serve well. While a very few home baristas may measure up against competition-level pros in technique and knowledge, the vast majority fall far short. How do you relate to someone who comes in and obviously savors your drinks, buys your beans, takes them home and then slaughters them in the filthy guts of a treasured Mr. Coffee maker?!

Boldy, I'd suggest we start those conversations (and I think we should look for them) around our commonalities -- our common appreciation for coffee as a drink that's more than God's natural alternative to Red Bull, our common stories of important moments shared over coffee. I think we would do well to start by listening to their unique coffee story, even when much of what we hear appears to be completely wrong. And I think listening first will open the door to those coffee recommendations we long to give.

Thankfully, many coffee lovers already ask us for advice, but even there, I think inviting them across that knowledge gap slowly and respectfully will pay off in the long-term, both in terms of increased customer value and terms of valuing and respecting a fellow traveler's love for a beverage that we enjoy so much.

What's in their cup? 

Pour Over Panic: The Problem of What to Watch

Pour overs are something of a discipline for me now. I relish the seemingly insurmountable challenge of the perfect pour in much the same way that I used to thrill at the challenge of climbing 5.12 clean.

In both cases, I fall short. One issue in particular that dogs my pour over practice is the challenge of learning what to pay attention to as I pour. Given one indicator to watch, I feel confident of finding flow and getting past the mechanics of technique into the coffee itself. Right now, though, I find myself more harried back and forth between indicators than anything else

While I know my core parameters are pour position and rate balanced against drawdown rate, I find myself slipping with the kettle because my attention is drawn away from the bed to the clock or the serving vessel. Currently, checking time, poured coffee level and pour placement require three different head movements. I suspect a better brew setup could move all three indicators into a single line of sight - a heads down display, so to speak.

Lighting the brew station properly seems to be another common-sense tweak that would improve the visibility of the process, and potentially sharpen my focus and responses. While I've seen several well organized pour over setups, very few of them address lighting thoughtfully. Interestingly, the popular bottom-lit serving vessel seems to be at best irrelevant and at worse a distraction, as it forces a barista to constantly adjust to different light levels between the vessel and the brewing device. I'd like to build a balanced lighting setup with even light levels and minimal shadows both above and below the bar level.

So, the brew station needs work. Aside from that, though, what should I be watching in the pour itself?

Nik Virrey (@xenvoix) brewing on a well-lit setup at new Zoka South Lake Union.

Pour Over Technique Followup: Cole's Pour

In the last post, I lamented the sad state of pour over documentation. Cole McBride took pity, and offered to put his technique on film. So here it is, the first of hopefully many pour over videos illustrating the rich and varied ecosystem of specialty coffee prep techniques.

Enjoy.

How Do You Pour Over? And Why? - A Running Pour Over Technique List

Yes, this entire post is about the ways you can pour water over coffee. I've heard (and forgotten) more of these techniques than, well, actually gotten to try them. It seems no gathering of coffee nerds is complete without an extensive discussion of technique that usually far outpaces the number of actual pour overs consumed (which may not be a bad thing for our collective caffeine levels).

The problem arises when attempting to replicate the bomber technique previewed at the local confab on one's home brew bar. With conversation flying thick and fast, I find it difficult to pick up the nuances of brewing technique face to face. Hence, this list, and (hopefully) your help. The idea is to have a handy and growing list that can be referenced, updated and linked to easily.

Below I'll start off with two techniques I practice. Yes, only two. I've seen many other methods, but since I don't practice them myself, I'd rather let actual practitioners do the explaining.

Pour over maestros who append their recipes (or link to videos) below shall be included (with full credit) in a full and updated listing here at a time TBD.

1. Continuous Low Disturbance Pour
Container: V60 into 3 cup press
Filter: what else but?!
Metrics: volumetric, 12 oz
Dose: 23-24g
Time: 2:25

Summary: It's as easy-hard as it sounds. Let bloom for 40 seconds and then pour slowly and continuously in the center, keeping the top of the bed about even with where it was during the height of the bloom. Shoot for hitting 12 oz right around 2:25 and then switch in a drip cup and let the dregs drain out.

2. Continuous Circular Disturbance Pour

Container: V60 into 3 cup press

Filter: ours

Metrics: volumetric, 12 oz

Dose: 22-23g

Time: 2:15

Summary: I may be wrong, but the circular pour seems to extract a bit more quickly than the zen center pour in #1. I tend to bloom for 30-35, and then gently pour in continuously expanding and contracting circles shooting to hit my volume for a 2:15 pull out. Bed height is kept low, about where the top of the bloom is. The idea, if any, is to spread the poured water around to increase evenness of extraction and eliminate the possibility of an over-extracted center. In my very limited experience, it seems a bit trickier than #1, but maybe slightly juicier and brighter?

Ok, now it's your turn. How do you pour over? And why?

Reflecting on Luis Garzon, Coffee Farmer

It seems of late that everyone has posted a "why coffee prices are rising," and I do not intend to repeat the excellent explanations offered by the likes of Mercanta or Counter Culture.

I did think it was worth highlighting a post by the New York Times illustrating the human cost imposed by strange weather at coffee origins. The story of coffee farmer Luis Garzon reminds me that any shift in lands suitable for coffee production will be accompanied by real suffering, as farmers see the value of their skills and the viability of their land both devalued by changing weather patterns.

It's certainly hopeful that the GCQRI and academics at origin are working to develop sustainable solutions for specialty coffee, but the process of uncovering the future of coffee will be messy and for now many farmers are going to have great difficulty staying in business.

Really, I suppose the story of Luis Garzon reminds me that there is a flip side to the challenges imposed by high prices on cafes and roasters. Those high prices reflect the difficulty that many farmers are having producing excellent coffee for all of us to enjoy.

Indeed, I could imagine that production problems on a coffee farm would be more challenging that dealing with peak green prices. While we consumers can pick and choose our coffees, producers must stick with their trees or risk considerable expense uprooting them and waiting for a new crop to grow. Worse, many farmers must make these choices with a minimal safety net, literally risking their children's educational future for coffee.

As usual, when I really take time to read about the work and risk that goes into producing my cup, I come away humbled and incredibly encouraged by the passion that farmers like Luis display for our beverage.

New Frontiers in Coffee Research

Reposting a great note from Sweet Maria's about the next steps in coffee research, courtesy of the GCQRI. This sort of work is exactly what I was hoping for in my old post on a Coffee and Perfumery Radar.

The three big initiatives mentioned:

1. Use NIRS (Near Infrared Spectrophotometry) to develop a global "fingerprint" database of green coffees from various regions, chemically identifying coffees by region.

2. Another related project involves rapidly scanning the thousands of compounds in green coffee to identify those related to cup quality. No details on particular methods given.

3. Finally, a project called NextGen Coffee Sensory Evaluation will attempt to correlate specific flavor descriptors identified by a panel of tasters with particular compounds in the coffee, essentially combining human and electronic noses so we understand better why a coffee tastes like sweet cherries and how we can keep it that way.

Reflections on Brewers Cup

Last weekend, I had the privilege to participate in the first Brewers Cup competition. Here are a few of the thoughts I've been mulling since then, in no particular order.

1. Q graders? On the one hand I appreciate the sensitive palates that Q graders bring to the table. I really valued the feedback I got from the judges on my scoresheets. On the other hand, is it appropriate to grade a simulated slow bar with tools designed for the cupping table? I think some brew methods are going to have inherent handicaps with the current system. I noticed, for instance, that no aeropress brew made it to the finals, which were evenly stacked between immersion brew methods and pour over brew methods.

2. With a single, brief practice session and no pre-announcement of the coffee, the first round seemed to be all about how quickly a barista could dial in a strange coffee. This is a useful skill, no doubt, but I think a test of brewing skill would be more accurate with more practice time and publication of the chosen coffee ahead of time. The latter certainly simulates a slow bar experience more accurately.

3. It would be useful to have more guidelines for the presentation. It emerged the day before finals that this was supposed to be a simulated slow bar presentation to a pretend "customer," and sensory aids were discouraged. In particular, I found it unclear where I should or would be graded on things like origin notes. Is that customer service? Taste description? Overall impression? Maybe it's just me, but I find myself concluding from the score sheet that the quality of my chinaware seems to be weighted as heavily as my taste descriptors. This didn't seem to be the case in reality, but that just adds to the confusion. For reference, here is the finals round score sheet.

4. Staging was definitely a challenge for Brewers Cup, and throughout the event I got the sense that all of us were poor second cousins to the barista champions on the main stage. I'm not sure that lack of limelight is necessarily a problem, but I think defining Brewers Cup space more specifically as separate and distinct from the barista championships and the audience would be helpful. At the very least, let's put up a little stage and film competitors, and maybe use a separate room.

5. No siphons? Come on, one of us should at least give siphons a shot in Houston!

Finally, a note to myself: only use a coffee that has been singing for you in the finals! My chosen coffee behaved like a stubborn mule during dial in sessions the night before and the day of, and it kept on being uncooperative right through finals. Maybe I should have switched at the last minute...

Any other thoughts from competitors? Don't miss (awesome!) organizer Nick Cho's Brewers Cup Flickr feed.

Holes in my Coffee Catcher

It might be a good thing, and it certainly could be a blues song.

In the run-up to competition (upcoming post on that) I began to experiment with deliberately increasing interaction between the compressed bed and the pre-infused water in the double Coffee Catcher technique. Results were frustratingly inconsistent, but sometimes fantastic, bringing out more juiciness and body with some coffees than I could get with a non-perforated Coffee Catcher. About a week before Brewers Cup, I made one of my best coffees ever using a perforated double catcher technique with 49th Parallel's Blue Batak coffee.

The first-round coffee for Brewers Cup seemed to over-extract with a perforated Catcher, so I went with a fully-sealed top Coffee Catcher for the first round, and that was (obviously) a good choice. In the finals, I struggled to dial in my coffee of choice, and eventually went with a perforated Coffee Catcher. I didn't get the consistency I wanted between three French presses, but I think the extractions were still better with that particular coffee than I would have gotten with a fully sealed Coffee Catcher.

File this under puzzles I haven't solved yet.

The hole is longer and narrower than the head of a screw.

The Demerits of Frozen Beans

This was too great a video not to repost! The original is over at the Seattle Coffee Gear blog.

It's surprisingly hard to craft entertaining content that answers basic consumer questions in a creative, non-threatening way. Great job, Seattle Coffee Gear!

The Problem of Water: Looking for the Ghost in the Machine

On Saturday evening, I set out on an elusive chase to identify potential taste contamination stemming from my brewing equipment. I taste-tested my pour over brewing kit with boiled, Brita-filtered water.  


The results were surprising.


I tested twice: once on a well-used K250 V60 filter and once on a new filter. In each case, I used a Hario Buono pouring kettle, a Copco Fusion boiling kettle and a glass V60.  Drinking containers were glass or ceramic. Each pour wetted the entire filter in a circular motion.

Tasters: myself (Nate), my lovely wife and Katherine Hartline of Trabant / Mercanta


Each test used three separate cups:

1. First pour through a dry, room temp filter. Approx. 12 oz.
2. Second pour immediately after first through the same filter. Approx. 8-12 oz
3. Third pour straight into a drinking container as a control. My Hario tended to run out of water about this point, so after about 4 oz of Hario water I topped up from the Copco.

In each case, we observed the surface of the water for visible oils and tasted the three cups (not blind). 


For the used filter, the first pour revealed substantial floating oils, a slight coffee taste and a metallic taste. Pour two yielded very little oil, no coffee taste, and a hint of metal. The slight acridity of the metal seemed to balance the sweetness of the Brita. Pour three revealed a distinct metallic taste, somewhere between the first two pours. All three of us preferred the second cup.


For the new filter, results were similar, without the complicating factor of the coffee. Again, we preferred cup two.  


What does this mean? Instinctively, I'd suggest it means that a pre-rinse immediately before brewing and minimal dwell time in the kettle are both key factors for minimizing hints of metallic contamination in the brew. While I'd kept brew time minimal before the experiment, I had also been failing to pre-rinse, so these results suggested a change in routine. Since the experiment, I've incorporated a pre-rinse into a couple of brews and found no discernible metal taste.


Of course, these results aren't bullet-proof.  For one thing, using Brita water simplified the problem by taking the vexing variable of dissolved solids out of the equation. We also didn't get into the effect of cleaning methods / products or the hairy question of taster's bias, which is a particularly pesky ghost in the machine. 


Despite uncovering some new questions, we were able to uncover some reasonably definitive results that changed the way we brew.  Here's to incremental improvement!