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.

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.

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.

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:

• a traditional four minute brew (add water and coffee, shake gently at 3 minutes, press)
• a French press skim (Wendelboe/Hoffman technique) 
• a French press shake 
• a Coffee Catcher pull
• a Coffee Catcher press 
• a double Coffee Catcher

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.