Espresso - Techniques for Home

After a few years of making espresso at home,  it's time to write up some methods and observations about home machines, grinders, coffee beans, and results.

The espresso machine:  Espressione Minuetto Professional  (~$149)
The grinder:  Capresso Infinity  (Jura, Inc)  (~$99)   Conical burr grinder.

Modifying the portafilter basket for finely ground coffee.

Top of basket showing array of fine holes in first wall.
The second wall is less than a millimeter below the first one.

Many home machines come with double-wall baskets.   The first wall has the same small holes as a single wall basket.  A second wall,  with a single larger hole , is used to slow the water flow when a  coarser coffee grind is used.   If you use finely ground coffee, the total resistance could be too high.  This can lead to a slow extraction  (see below for times,  etc.)  I used two approaches:  1. enlarge the hole in the second wall, and 2. remove the second wall entirely.   Both approaches risk penetrating the first wall which will render the basket useless. 

First method:  I used a drill to  enlarge the single hole in the second wall.  I damaged a basket by drilling though the first wall.  On the second try, I was more careful.  Second method:  I removed the entire second wall by carefully grinding around the edge of the basket.

Basket with second wall removed by
progressive grinding around the edge.

. 

Basket with enlarged hole in second wall.  

 Note the risk of drilling through the first wall.

Espresso Making at Home

It's easy to "choke" an espresso machine with a too fine grind or by pressing too hard with the tamper-  choking occurs if the flow rate is very small, or zero, when the basket is pressurized.   Note: Never attempt to remove a portafilter under pressure.  If the machine is choked turn it off and wait for pressure to subside.   Most machines have a pressure relief path in the off postion.  Be patient.  

Finding The Right Grinder Setting

The two finest settings on the grinder are useful for espresso.  The others are too coarse.   I found that the optimum grind depends on the bean characteristics.  Sticky beans need to be ground a bit coarser than dryer beans.  

Tamping

A solid metal tamper is required. The tamper must match the basket diameter closely - around half a millimeter smaller.    

Caffeine: Traditional Sources - Plants

Caffeine is the most used drug on the planet.. (see Wikipedia link for details).   This post is related to where, and how much,   caffeine is in plant sources. 

• Coffee -   The plants are called Coffea Arabica  and Coffea Canephora .   Cheaper, easier to cultivate,   robusta coffee comes from the Canephora varieties and has almost twice the caffeine of arabica.   Espresso blends contain significant amounts of robusta beans.  Concentrations of caffeine are usually quoted in percentage of dry bean weight.   Using 2% as an average -  one scoop of coffee (about 12 gm) would have  240 mg of caffeine.   The amount extracted from drip methods could be about half. 
•  Tea -  Camellia Sinensis .  The leaves contain an average of 3% caffeine by dry weight.  
• Maté -   Ilex paraguariensis   and Ilex Guayusa.  This South American plant has leaves which contain about 1% caffeine.
•  Guarana -  Paullinia cupana .  The seeds of this Amazonian climber contain about 2% caffeine.
•  Cola (Kola) -  Kola Nut  from Cola Acuminata . The nuts/fruits  contain about 2% caffeine.
• 
  

Drip Coffee Making Techniques

Some rules from decades of drip coffee making using German-made machines - Melitta, Braun, etc.

• Measuring is crucial. Most manufacturers use their own measures. Typically,   one drip coffee measuring spoon/scoop makes one drip coffee cup (water volume) of brewed drip coffee.  Neither measure is standard so it's useful to find out what your machine really uses in standard units - metric or English.   
• A drip scoop of finely ground coffee is close to 2 tablespoons in volume.  In metric units that's about 30 ml (milli-liters).  Sometimes weighing ground coffee is convenient.  The density of  uncompressed (loose) dry ground coffee is about 0.25 grams per ml  For compressed finely ground coffee, it's closer to 0.4 grams/ml..  So one scoop weighs about 30 x 0.25 g/ml,  or about 7 grams.  You can test this by weighing several scoops on a small postal scale.  One ounce (not fluid ounce) weighs 28.35 grams.   Two scoops should be close to one ounce. Zero out the empty container weight first.  (We all forget to do this at least once)..
• One "cup" of drip coffee uses five to six  fluid- ounces of water. In metric units that's 150 to 180 ml.    Note: these are volume measures.
• Make just the right amount.   Don't attempt to use the full capacity of a ten cup maker.   And making one cup at a time won't work well with a large coffee maker. 
• Selecting the right grind is important.  If the grains are too fine, they will clog the filter. If they are too coarse,  the extraction will be poor.  
• Water contact time and temperature are important parameters.  Properly calibrated drip coffee makers do this for you.   I like to use Melitta style paper filters (line-bottom cone) in combination with the gold mesh.  Simplifies clean up. 

Coffee, One of the Essential Elixirs



My cuppa espresso -
the reason I was able to post this

I read this article, in paper form, in the best coffee house in my neighborhood (their espresso is sublime and ineffable). It's from the Guardian Weekly, a digest which includes international news, analysis, features and book reviews from the Guardian, plus select articles from the Observer, the Washington Post and Le Monde. The Guardian company has a long history.  It started out as the Manchester Guardian in 1821.  The company nows owns the London Observer,  a venerable Sunday newspaper (1791).  

Can coffee wreck your marriage? Poisonous brew or the thinker's drug of choice?  A new book of essays about coffee and philosophy seeks to uncover the truth
Stuart Jeffries, The Guardian, Thursday 14 April 2011

On 29 December 1675, King Charles II issued a Proclamation for the Suppression of Coffee Houses. He'd had it right up to the top of his vast wig with the Peace and Quiet of the realm being disturbed by Idle and Disaffected Persons hopped up on proto-espressos.

Bad to the bean: a coffee house at the time of King Charles II
Photograph: Lordprice Collection / Alamy/Alamy

Looking back, perhaps he was right. In 1675, the number of coffee houses in London was roughly 2,000; today that's the number of London baristas who said "Chocolate on top?" in the last minute. We've reached saturation point.

Back in 17th-century England, King Charles wasn't the only person who thought coffee was a social vice. The Women's Petition Against Coffee of 1674 claimed all-male coffee houses were responsible for "a very sensible Decay of that Old English Vigour . . ." by promoting "the excessive use of that Newfangled, Abominable, Heathenish liquor called Coffee, which . . . has so Eunucht our Husbands and Crippled our more kind gallants they come from it with nothing moist but their snotty noses, nothing stiffe but their Joints . . ."

But, to the disappointment of those petitioners, Charles bottled it. Two days before his proclamation was due to take effect, he backed down, fearful that his head might go the way of his executed father's – such was English fury about the suppression of an institution that had created the nation's first egalitarian meeting places, the so-called "penny universities".

The debate about coffee's merits has raged ever since. Is it a pernicious brew that causes impotence, arterio-sclerosis, heart failure, indigestion, insomnia, premature old age, pancreatic cancer, birth defects and bad breath, as well as poverty among the farmers who grow it? Or is it an inky nectar that helps prevent Parkinson's, Alzheimer's, liver cancer, gallstones, type 2 diabetes and colon cancer, improves motor skills and reaction times, promotes fair trade to the impoverished south and stimulates both intellectual acuity and social interaction?

The answer is, according to a new book of essays about coffee and philosophy, quite possibly all of these.

Coffee: Grounds for Debate, a title in the Philosophy for Everyone series, argues that coffee is a performance-enhancing drug for thinkers. "The appropriate analogy is that coffee and philosophy go together like foreplay and sex," insist editors Scott F Parker and Michael W Austin. "You can have one without the other, but the latter is better with the former and the former often leads to the latter." Philosopher Basam Romaya says: "With the use of coffee, critical thinking abilities are sharpened, attention to detail enhanced." This is a venerable claim: in the 16th century, Sheik Abd-al-Kadir, an Arab scholar, said: "No one can understand the truth until he drinks of coffee's frothy goodness."

Well, maybe. There is a big problem for such assertions, namely that coffee (an Ethiopian plant first cultivated in Yemen around AD575) wasn't around when some of the world's leading brains were working at full tilt. Aristotle never sipped a macchiato, Socrates didn't have a Caffè Nero loyalty card. Worse yet, some of the greatest later philosophers – Kant and Nietzsche, for example – were coffee refuseniks. Yes, Voltaire reportedly drank 60 cups of coffee a day, but not even the most ardent rookie philosophers should copy him. Costa hasn't created a nation of geniuses.

The book will also stimulate those seeking to understand the aesthetics and ethics of coffee. California philosophy professor and self-proclaimed coffee snob Kenneth Davids lists criteria for excellence: 1. Acidity is good; 2. Smoothly viscous or lightly syrupy mouthfeel is good. 3. Aromatic and flavour notes that are complex and intense are better than simple or faded ones. 4. Natural sweetness is good, too much bitterness bad. 5. Natural flavours and aromas such as floral, fruit, honey and chocolate are better than flavours that come from mistakes made during drying, such as mustiness or moldiness. 6. Long, sweet, flavour-saturated aftertastes are good. 7. The robusta bean makes worse coffee than the arabica.

Marvellous – except that many coffee drinkers don't have the same taste as Davids. for instance, there is something called the "rio note" – a harsh medicinal sensation apparently created by certain moulds. Americans like Davids hate it, but it is widely enjoyed in the Middle East and central Europe. Mmm, yummy – mouldy coffee.

So what about impotence? That does seem to have been overstated. The Women's Petition Against Coffee prompted a broadside from men who argued that it "makes the erection more Vigorous, the Ejaculation more full, adds spiritualescency to the Sperme". Initially I wasn't sure what "spiritualescency" means, either, until I read in this book that caffeine increases sperm motility. That said, some say coffee may harm the sperm while speeding it on its way, which makes a kind of sense.

All in all, the debate reminds me of what Homer once said about alcohol in The Simpsons – that it was "the cause of and solution to all of our problems". Coffee is like that, only more so.
-- end of included article--

P.S.  Note added for EKO, a fellow coffee aficionado.    Many coffee mavens (a shtikel of yiddish here) consider decaffeinated coffee to be an abomination - verging on the sacrilegious.   What is the  physiological basis of this extreme response to an otherwise rather pleasing product (when well made).  The answer probably lies in the molecule called  caffeine and it's many effects on neural and neuroendocrine systems.   The pharmacology of caffeine is summarized in it's wikipedia page (click "caffeine" link above).  It's a competitive inhibitor of adenosine at adenosine A1 receptors (see other subtypes) but also has a wide range of effects on many systems in the body.