Monday, November 29, 2010

K250: Now for AeroPress

Update: we're releasing our K250 mesh for AeroPress today.  Check it out here.

To sum up: no paper taste, easier on the elbow, and reuseable!

First Look: Kaffeologie K250 Mesh

Say hello to Kaffeologie's K250 mesh line for various pour over devices, and chemex.  Samples are being farmed out to reviewers and coffee geeks, and early results have been pretty positive.

So what's in the box?

The filter itself is a 304 stainless steel woven mesh meeting ASTM 2016-06, which is a set of standards dealing with filtration consistency.  The mesh contains 250 threads of .0016" wire per linear inch, and has an open area of 36%.  In other words, 64% of the mesh area is impermeable.   The mesh is doubled during assembly, yielding a net open area of approximately 13% (36% x 36%) and substantially slowing flow-through compared to a single layer.

Unfortunately, because materials differ there is no clear comparison between this open area and equivalent statistics for classic paper or cloth filters.  Any help in developing a common open area comparison for these other materials would be much appreciated!

With ingenuity, the doubled mesh can be adjusted to any pour over shape.  Cut seams are folded over to prevent leaks and stitched with either Argentium sterling silver or pure titanium thread.  A thicker piece of Argentium wire encircles the lip of the filter to maintain shape.

The filters can be cleaned by rinsing upside down and then soaking with puro-caf.  An early tester learned that turning the filter inside-out and scrubbing the seam (ala cloth filters) puts too much strain on the mesh and yields tiny tears.

We're still coming up with the don't-kill-yourself list of things not to do with your filter.  The only one I can think of currently is: This filter contains hot fluids during use.  Don't pick it up and burn yourself!

Finally, here's the first video of the filter in action.  More videos will appear in due time on the site.

Wednesday, November 24, 2010

Coffee Question of the Month

Here is a question that keeps bugging me.  I can't come up with a satisfying answer for what I'm tasting.

What is going on with this double catcher extraction? Separating the bed from the brew for 3/4 of the  brew cycle seems like madness.  Yet the coffee tastes better.  Brighter, crisper, with a distinctive silky body.  Is the catcher somehow dispersing the bed evenly as it is pulled at the 3rd minute?  This was previously suggested to me, but I'm not sure that dispersion at 3 minutes is a sufficient explanation.  For one thing, a significant part of the bed doesn't disperse, but stays happily atop the bottom Coffee Catcher.

Is it something to do with the final pull of the bed through the mixture at 4 minutes?  That seems a bit late.

I don't have a good explanation.  And I certainly can't account for two tantalizing clues: First, after pulling the first Catcher, the foam at the top of the press looks white, not coffee-colored.  Second, the bed consistently reeks delicious floral / perfumey aromas AFTER the brew.  If you don't think this is weird, sniff a bed from traditionally-brewed French press coffee.  

For those who missed out, here are a few videos: the original guide, plus a clip of the extraction in progress and an extended tasting.

Auto-Agitation for your French Press?

John ran into the Stir Brew device at a Chipotle on the east coast.

I may be un-tutored, but it looks like a patented auto-stir dealie for a beaker of coffee.

Anyone know anything else?

I guess it saves on spoon-wielding or press-shaking.

Thursday, November 11, 2010

First Thoughts: James Hoffman on Cupping, Nick Cho on Clever

First thoughts on two very interesting, and much-linked new pieces this week.

The first, by James Hoffman, details his attempt to replicate the cupping experience in a French press.  He fined up the grind and deliberately allowed the coffee to sit with the grounds in the press for 10 (!!) minutes prior to serving.  Result: high marks at the cupping table and via ExtractMojo.  Hoffman concludes by suggesting we may routinely under-extract our presses.

As usual, James gets points for taking the bull by the horns.  Why do cupping coffees still taste decent after 30 minutes, while French press coffee often tastes rancid?  Some commenters observed that the cylindrical design of the press (low surface area) leads to poor immersion of grounds.

My take: agitation (or lack thereof) is a critical differentiator between real-world french press consumption and the cupping room.  Fines can precipitate out of a still mixture whose surface is occasionally disturbed by a cupping spoon, but mixing the coffee as it is decanted and then lifting, swirling and sipping the cup continually re-involves the grounds in the brew process, pushing the brew toward over-extraction as it ages.  Tastier real-world French presses need to calibrate for quite a bit of agitation over the life cycle of the cup, which might mean a coarser grind than ideal.

The second piece, by Nick Cho, is an experimental video showing a pour over experiment in a Clever dripper using both a SwissGold filter and a standard paper filter.  The idea is to trap coarser grounds in the SwissGold, which can be lifted out of the brew prior to drainage.  Draining is then quicker, which allows Cho to increase immersion times without falling off the edge into over-extraction.

My take: Fascinating idea.  Kaffeologie is working on a Clever filter to go with our new pour over items, and I'll be trying Nick's suggestion with our prototype.  At first glance, the idea seems to increase the similarity of the Clever to full-immersion systems like the French press.  It would be interesting to deliberately map out a new world of pour over - press hybrids.  Way to think outside the box!

Friday, November 5, 2010

Five Tips for Better Drip Coffee

With the possible exception of the ubiquitous press, most of the brewing methods I see and use on a daily basis would be exotic to most coffee drinkers in the United States.  I've never written about the humble and much-maligned drip percolator -- until now!

If you are an occasional gourmet coffee drinker who relies on a Mr. Coffee, this post is for you.

1. Clean your coffee pot and percolator.  Daily!  Especially with the auto-heat function most coffee makers use, a thin film of coffee solids will develop on the bottom of your carafe.  The plastic tray that you place your filter in will also develop a layer of grime (coffee makers are usually made of a dark colored plastic to hide this nasty stuff and keep your percolator looking nicer than it is).  Grime in the percolator or the pot can do nothing good for your brew.  Remember there's no such thing as a "seasoned" coffee maker, and battle the stuff daily.  A wipe down with a paper towel and a hot water rinse does wonders for a percolator tray.  Use dish soap and hot water in the coffee pot.

2. Grind your coffee fresh, even if that means getting a cheap blade grinder.  If you use a grinder, keep it clean too.  One rule of thumb is to wipe down the grinder every time you change your coffee bag.

3. Know your coffee maker's brew cycle, and pour that pot as soon as it's finished.  Coffee ages most gracefully as it cools, and coffee on a hot plate gets stale quickly.

4. Rinse your paper filter under hot water before placing it in the tray and adding coffee.  A gentle but thorough rinse will get rid of much of the papery taste in the filter without damaging the paper itself.

5. Buy fresh, whole bean coffee weekly.  Look for a roast date on the package within the last week, and keep in mind that the coffee will unpredictably go stale somewhere around 14 days after roasting.

These best practices will help, but to be honest, most coffee makers have one fatal flaw that will consistently cause acrid flavors in your coffee: (relatively) cold water.  Coffee fully extracts at temperatures above 190 degrees Fahrenheit, and most coffee makers use water far below this temperature.  The combination of cold water with relatively long brew times produces a burnt, coffee-forward flavor that misses the subtleties in many great coffees.

The four steps above address other problems, but I'm afraid the only way to address the temperature issue is to fork over $300 for a hand-made Dutch Technivorm drip coffee maker. :(

Of course, if you get gourmet enough to buy a Technivorm, why not save cash and use a French press instead?