Monday, February 5, 2018

Overly-extractive coffee

Coffee is a great topic for a Monday morning post.

Many people are passionate about their coffee.

Many of us simply want a pleasant jolt of caffeine.

Both groups are vexed when we purchase a cup of coffee that is extremely bitter.  What causes that?

Over extraction
Coffee that is too finely ground for the brewing process is often bitter.  The wash of hot water first extracts caffeine and flavor.  Then it extracts tannins that make the coffee excessively bitter.

The coffee maker often does not have much control over the process.  Somebody else purchases the coffee and the 'grind' is whatever it is.  Management is unlikely to appreciate us peons tinkering with the guts of the coffee maker.  What is a coffee lover to do?

Mrs ERJ's wisdom
Mrs ERJ was reminiscing of the days when she was kitchen help at a summer camp.

Ever one to step-up and do more than her share, she awoke early one morning and made coffee for the crew.

She remembers, with chagrin, that the coffee was horrible.  It was pale and weak.

In an effort to make the coffee percolate more quickly she had filled the urn with hot water.  The urn perked until the thermostat in the base sensed the brew was hot enough.

The take-home lesson is that the starting temperature of the water is a key variable in how extractive the common coffee urn will be.  The coffee maker might not have control over the grind of the coffee or the thermostat in the base of the urn but they can control the temperature of the water at the start of the process.  Try using slightly warmer water if your perc-ed coffee is too bitter.


  1. If you get an aeropress and a burr grinder, you can precisely control coffee/water ratio, grind size, water temperature, and time of extraction. If you don't want to invest in a burr grinder, you can adjust grind size by buying the bulk coffee at Meijer and using their grinder, which allows you to adjust the grind size.

    With my aeropress, I use 25 grams of coarse ground coffee to 1 cup of water at 195-200 degrees F, let is sit for 30 seconds and then use a slow press that takes about 10 seconds. It uses a lot of coffee but the result is a strong cup of coffee with no bitterness. The drawback is that the aeropress only makes 1 cup of coffee at a time and isn't suitable if you're hosting an event at which many people want coffee.

  2. Grew up on Cajun coffee, as long as it's black and strong, I'm good... :-)

  3. I've been buying green coffee beans and roasting them in a hot air corn popper for years now. Resulting coffee has more subtle flavors, is smooth and not bitter. Most commercially roasted coffee is the equivalent of eating a steak that's overly well done.
    I prefer using a french press to make the coffee as it's not filtered and thus is more flavorful.


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