Friday, October 29, 2010

Up Dosing in the Siphon

Friday's puzzler for you caffeine geeks: why does a vac pot seem to require consistent up dosing to brew a good cup?  I tried SCAA cupping standard ratios, and the brew tasted acrid and over-brewed.  Upping the dose to 11.5g per 150ml (40% up dose) produced much more satisfactory results.

Why?

My own two cents: The bottom-up agitation combined with top dumping of the coffee means the coffee is particularly hard to mix into the water consistently throughout the relatively short brew cycle.  If it takes 20-30 sec to wet all the coffee, that's 25% of the brew cycle.  A higher dose may be a shortcut to better brewing ratios from the start.

Monday, October 25, 2010

The B.S. Gap in Coffee

The specialty coffee world is well stocked with coffee nerds -- including me.  Unfortunately, precious few of us seem to have majored in the hard sciences at school (this also includes me), and the result is a startling dearth of scientific knowledge amongst coffee's best and brightest.

This doesn't stop us yakking.  In fact, an amusingly high percentage of coffee professionals seem to have permanently locked lips with the Blarney Stone.  Though the last burst of hard research on coffee was in the 80's, we suggest scientific reasons for much of what we do (or don't do).  I hear science invoked in vac pot discussions, pour over disputes, and espresso machine showdowns.  On this blog, I do my part with my ongoing speculations on the French press and the Coffee Catcher. 

So is it bad that we propose seemingly reasonable theories without the hard research to back them up?  I don't think so.  I love the creative dialog that emerges from asking questions and suggesting possible answers.  I think the give-and-take itself helps us to weed out crackpot theories and identify the good ones.  I think we depend on our palates to move the process forward where we can't explain the science coherently yet.

All this talk is much better than nothing, but there's a limit to how much we'll learn without some new coffee chemistry research.  In 30 years of innovation, I think we've accumulated a gigantic scientific deficit of questions, and I think it's costing us a thorough understanding of what we do right now, and how we could improve coffee in the future.

Don't get me wrong, I love shooting the breeze with my coffee buddies, but at the end of the day, I want some answers. I want to understand more about how different brewing and processing methods affect what's in my cup.  This isn't rocket science.  The answers are out there, yet I can't find anyone who is working on finding them!

So here's a challenge: let's get some of the BS out of coffee -- by bringing in a few B.S. degrees.

Credit for inspiring this post goes to Andrew Daday of Stumptown Coffee.







Monday, October 18, 2010

The Double Catcher: Brewing by Vacuum Dispersion?

Credit for this post goes to Kyle Watson, better known as Mr. Crampy to biking enthusiasts around Redmond.  Over a steaming cup of double-Catcher Koke this morning, Mr. Crampy drew on his physics background to explain how the double Coffee Catcher brewing works.

Pulling the first Coffee Catcher creates a vacuum beneath the rising Coffee Catcher. The vacuum isn't perfect of course, but Mr. Crampy thinks it's sufficient to generate an efficient dispersion effect, completely mixing the coffee and grounds to produce a very even extraction. He suggests this even extraction is the reason for the coffee's particularly clean taste.

This is by far the most reasonable explanation I've heard for the phenomenon. While convinced this method tastes great, I'd been stumped as to how extraction worked properly with the coffee locked away for 3/4 of the brew time. Perhaps the agitation and negative pressure Mr. Crampy alludes to accelerates the brew during the final minute.

Here's a movie of the process. Other double Catcher videos over here.

Thursday, October 14, 2010

Tasting Six Presses

I wanted to brew six different presses this week, and taste them blind and side-by-side. In the event, I attempted to brew five and failed miserably.  The six methods I wanted to investigate will be familiar to regular readers of the blog:
The idea was to set up a double-blind tasting, in which both I (the brewer) and my tasting colleagues would not know which cupping bowl contained which coffee.  I even brought multiple coffees and dreamed of repeating the experiment to evaluate the results from multiple origins.

We brewed at Street Bean Espresso, which is a fine tasting venue and which I frequent for it's Trapicitos French Press.  I learned a great deal about how to conduct a future experiment properly, and I think we all had fun, but I did not discover much about the differences between these press variants.

A few reflections:
  1. An experiment involving 5-6 simultaneous presses needs 3 baristas in order to avoid over-brewing several presses.  More on that below.
  2. Voting for coffees can be fun, but only if chits are water-proof.  Paper is flimsy.  Also, voting for 1st to 3rd is a lot less confusing than voting 1st to 5th, since people lose track.
  3. Finally, treat the data with a healthy dose of skepticism.  Here's how the votes turned out:











At first glance, the shake seems a runaway winner, with the double catcher and single catcher more or less tying for second.  The pull is the clear loser.  Closer inspection, though, reveals a number of problems.

  • The graph is displayed in the order the coffee was brewed, left-to-right.  Due to the pulling and pressing and shaking of the left three coffees, the last two presses were over-brewed.  In this context, it's worth noting that we tasted a lot of bitter acrid oils in the French press pull.
  • Not all coffees reached the table at the same temperature.  Due to temperature exchange during shaking, the French press shake coffee arrived substantially cooler than the other four coffees.   Coffees tend to open up and taste sweeter at cooler temps, and temps also influence palate sensitivity.  Finally, first impressions matter.  We all thought the shake was super-sweet and juicy right off the bat.  Did we give the other coffees an equal chance?  Probably not.

Is tasting a quixotic quest?  I don't think so.  I do think we need to develop a set of best practices for vertical tastings similar to the SCAA standards for coffee cuppings.

Thursday, October 7, 2010

Double Coffee Catcher Cleaning Power!

I confess, I still don't know exactly what's going on here. But the visual (and gustatory) differences are stark. Check it out.
The Double Catcher. Note the corona effect. 
Traditional French Press. Note the color and clarity change.







































So - what's going on here?

Wednesday, October 6, 2010

Climate Change & Coffee

Right up front, I'll confess that of necessity this article is speculative.  Climate change is coming, it will certainly affect coffee (and may already be doing so), but we don't know exactly what the future holds.

That said, I'd like to lay out some insights that have emerged as I try to make sense of my online reading and a few real-world conversations.

First, although the map of coffee is shifting, I think that is not inevitably for the worse.

Recent blog posts about the death of Kenya coffee and touching on falling crop yields in Colombia are standout examples of an emerging awareness of the fragility of the current coffee map.  Magnifying the effects of recent crop disasters in terms of global warming, the conversations I've had and articles I've read tend to end on a down note (to put it mildly!).

Climate change, though, is a fickle thing.  Warming climes will expand the coffee latitudes northwards and southwards to regions that have previously been too cool for coffee production.  Fancy a fine Argentine arabica?  What about micro-lots from northern Pakistan? I don't know whether either of these regions would actually be appropriate for cultivating fine arabicas, but I think it's important to note that the coffee map is already expanding.  Where will fine coffee come from next decade?

Altitude is another climate-shaped variable.  An old Reuters article reports that in Costa Rica, 2000 m arabicas are now possible in a region where 1800 m was the previous high.  Meanwhile, lower altitude coffees are struggling.  A stark example of the latter is a depressing map posted by Dr. Hayes-Bohanan of Vanderbilt, ripped from a UN study on Ugandan coffee.

If coffee cultivation begins to move up fragile mountain slopes, that will uncover all sorts of biodiversity challenges for the coffee industry.  Our industry best practices, including labels such as Bird Friendly or Rainforest Alliance certified as well informal direct trade arrangements, will need to be updated to reflect the changing standards required for the new micro-climates in which coffee is cultivated.  In some places, we may need to give up coffee cultivation entirely rather than irreparably damage rare habitats.  Overall, I suspect the biodiversity challenges we've begun to address in the last 15 years will turn out to be the tip of the iceberg.

Finally, I don't think coffee cultivation in warming areas is necessarily doomed.  The key will be managing coffee plant stress in new ways. In the blog post linked above, James Hoffman discusses the development of a new, rust-resistant strain of coffee in Colombia.  Whether or not this particular varietal catches on, the coffee gene pool is a critical resource that is crying out for more attention and protection from the industry.

The standout issue here is the rapid erosion of the coffee gene pool in Ethiopia, coffee's homeland, due to the superior economics of growing khat.  Here are a few insightful posts on the problem: The Khat Economy, and Khat and Development.  While the market is skewed towards robust, quick-bearing, and high-priced khat, the spread of khat can be reversed, as this article from the Yemen Times suggests.  If khat continues to replace coffee, I expect we will lose so much of coffee's genetic heritage that our ability to actively manage coffee's adaption to climate change will be severely constrained.

The other key adaptation for warmer climes lies in innovative coffee cultivation and processing methods.  The previously linked article on Costa Rican coffee cultivation describes emerging best practices of intercropping and shade-growing coffee that reduce stress on coffee plants at lower elevations.  These seem like best practices regardless, and it's encouraging to think that responsible cultivation methods seem to build more resilient coffee cultivation communities.


Here are my conclusions, so far:

1. I think we need to prepare to explore new coffee lands in the next decade.  What does that exploration look like for the specialty industry?  What kind of resources do we need to set aside soon to help construct coffee cultures in emerging coffee lands?


2. In order to manage the challenges to biodiversity that changing coffee cultivation poses, we're going to need some new tools:

  • a new vocabulary covering changing environments, processing methods and standards
  • new cultivation and processing methods
  • conservation principles agreed at all stages in the value chain
  • a new set of evaluation methods, including updated labels

3. I think we need to aggressively address the erosion of coffee's genetic heritage, particularly in terms of the emerging importance of khat in Ethiopia.  One way to address this is simply to pay more for coffee.  Other, more complex mechanisms may be needed, too, such as a type of Payment for Ecosystem Services (PES) that incentives the government and communities of Ethiopia to preserve the heritage of coffee for all of us. The proposed REDD scheme of rainforest payments is an example of a PES. More info here and here. Innovative coffee financing instruments may be needed too, providing coffee farmers with some form of security during the bad years that are likely to come more frequently with climate change.

4. Most of all, I think we need to become more involved with coffee farmers and processors as they struggle to adapt to changing climate.  It's too easy to wring our hands and mourn the loss of our fine Kenyans or last year's Harrars.  We need to get our hands dirty and support the communities who have produced these fine coffees.  That will require cycling back some of our profits to the coffee lands, providing resources to help farmers adapt to the threats posed by a changing climate.  Fine coffee is not a lost cause, but the extraordinary challenges posed by climate change call us to be more proactively and positively engaged with the coffee lands than ever before.