Thursday, November 29, 2012

Coffee Talk - Better Coffee Through Chemistry; Chemex


Lets face it, it's more of an Icon than a coffee pot.  It's part of the permanent collections of museums such as the Museum of Modern Art in New York, the Smithsonian, the Philadelphia Museum and the Corning Museum.  Mary Tyler Moore used one on her show (the Mary Tyler Moore Show) and Mia Farrow used one in Rosemary's Baby.  Ever the vehicle for "Brand Placement", even James Bond likes his morning coffee brewed in one (From Russia, with Love, 1963).  And you can't possibly have missed the one sitting on the counter in Monica's apartment on Friends.

(Photo Courtesy of Austin Baker; Friends episode circa 1998)

Invented in 1941 and patented in 1943, the Chemex was the brain child of Chemist Peter Schlumbohm. He combined a modified laboratory funnel with an erlenmeyer flask to create this ingenious 1 piece brewer that has become a classic in Mid-century Modern design.  Originally hand blown into a mold by skilled Corning workers in NY, these Boro-Silicate glass (Pyrex) coffee receptacles' are still being produced today.  Sadly, most of the ones available on the market now, are machine molded in Taiwan, though human "mold blown" ones are still available for a much higher price.

The timing for the premier of this modern marvel could not have been more perfect.  Most metal fabrication had shifted to armament production as America's forced entry into WWII loomed ever closer.  This all glass brewer did not stress wartime resources and thus was a big hit.  On a side note, most of the vacuum pot makers, such as Cory, switched to a ground glass seal design to relieve the need for a rubber gasket during wartime.

Though a Chemex, for all intensive purposes, is nothing more than a manual drip brewer, there are a few differences.  Chemex uses a proprietary filter paper that is about 25% thicker than your standard auto-drip filters.  Originally this filter paper came flat packed and needed to be folded into quarters.  Luckily, they come pre-folded now.  This is a godsend to persons like myself who are incapable of even the simplest of tasks in a non-caffienated state.

This special filter paper performs 2 important functions. First and foremost, it slows the brewing time.  This gives the water more time to mingle with the grounds, allowing them to "bloom" properly, thus improving extraction. This is where I bash the Keurig and Nespresso, because this is true of ANY proper coffee brewing method.  It takes TIME.  I admit the pod brewers are convenient, but they brew so incredibly fast that there is no time for the full flavor of the coffee to be extracted.  You can rush a cup of coffee, but you can't rush a great cup of coffee..... I'm just sayin'.

The second purpose of these thicker filters is to capture the less desirable volatile oils as well as the fine sediments that can make your coffee bitter and muddy.  This leaves you with the richest and smoothest cup of "Joe" you ever sipped.  It's like liquid jazz in your cup.  Seriously, I kid you not.
I have heard complaints from "purists" that you can taste the paper.  That may be, though I don't so much notice it myself.  As a result, several companies have come out with stainless steel micro filter cones.  Before anyone spends $100.00 on a stainless steel micro filter for your Chemex, it should be noted that those filters will only trap the fine particles, so the "undesirable compounds" from the grounds will still make it into your coffee... It should also be noted that if one wets the filter with hot water first, before adding the coffee, it tends to lessen the "paper flavor".

Chemex is one of the most "hands on" ways to brew your coffee, even more so than a French Press, which is really more of an infusion than a brew.  With Chemex, it's all in the ritual of P and P (Prep and Pour), that is Preparing your Chemex for infusion and the Pouring of the water.

First, THIS is my Chemex. 

According to the Patent number stamped on the bottom (2,411,310), it was manufactured in 1946 by Pyrex in Corning, NY.  The way I understand it, the patent number changed in 1947 to 2,414,901.

Because of it's age, I know that it was mold blown; meaning that it is borosilicate glass that was blown into a mold (as opposed to the mechanical mold pressed ones made today).  I bought it used, obviously, since it is 23 years older than I am.  It seems to have been much loved by the previous owner(s).  It was brewed hard and put away wet, as it were.  The finish on the wooden collar is almost completely worn away and there appears to be some overheating scars as well (where the wood has blackened) no doubt from being kept warm on the stove burner (yikes!).  I usually keep my resulting coffee warm in a thermal carafe, for it is true that the Chemex will cool fairly quickly after brewing.  But this is also true of the French Press and Vacuum, so I am use to using thermal storage devices for unconsumed coffee.

Eventually, I plan on replacing the collar, bead and tie; but it's not really a high priority and would take away from it's vintage "aged" look.  The glass is in perfect working order and the collar is still secure so there is really nothing wrong with it at all.  A perfectly serviceable piece of vintage coffee brewing equipment to make 40 oz (that's eight 5oz cups) of rich, dark and sultry elixir.

OK, Lab Glass?  Check!

Chemex filters can be ordered online, but the cost of shipping doubles the price.  I found that Cost Plus/World Market carries the filters (prefolded and unbleached) in boxes of 100 for $7.59.   They also carry the newer mold pressed version of the Chemex, made in Taiwan.  (I love World Market)

Filters? Check!

OK, start heating a kettle with the appropriate amount of water. (in my case, 40oz)

Grab  filter and separate 3 layers from the 4th layer to form a cone.

Insert the "cone" into the top of the Chemex infuser with the 3 layers towards the pouring channel. (This will prevent the filter from blocking the pouring channel, which acts as an air vent during the extraction process)

OK, now is the time to add coffee...  The directions usually state 1 rounded Tablespoon per 5 oz cup...

Personally, with this particular brewing method, I think it needs to be toned down a little to a level tablespoon per cup.  So I am using 8 Tablespoons of Peet's Major Dickinson's Blend that has been ground for an auto drip machine. (Basically, "standard" grind)

"Preparation" is complete.....

By now, your water should be pretty close to a boil.  When it does boil, remove from the heat and allow the water to set for a minute. (this will bring it down to about 205F degrees)

Now it's all about the "Pour".

Drizzle just enough water from the kettle to moisten the grounds.  Then stop. (This allows the grounds to absorb some of the water and bloom)

After 20-30 seconds, you may pour in a little more water, just until the grounds look saturated. (They may even begin to bubble up from underneath... This is a good thing)

Now, slowly continue pouring the water over the grounds, keeping them wet, leaving at least 1 inch of space below the top of the carafe. (it should take you about 4 minutes to pour 40 oz of water through the grounds

The ground should be saturated at all times throughout the process.  The key to a great "POUR" is to ensure the grounds never have a chance to get "dry".

Once the water has drained through the filter, you will notice that the remaining grounds look NOTHING like they would if you used an auto-drip machine.  They have almost become a gelatinous mass due to this "blooming" and infusing method of brewing coffee.

Take the points of each of the corners and lift to remove the spent grounds and the filter. (Dispose of them in the trash or in your compost bucket)

There you go.  Coffee via chemistry.

Now pour yourself a cup, move the rest to a thermal carafe, and kick back while listening to some Jazz... The perfect accompaniment to a perfect cup of coffee.

Cin Cin!!

1 comment:

Patti T. said...

Shane this was a very interesting post. I love the convenience of my Keurig, but I guess I know now why I never get a really good cup of coffee from it.