The Latte Process

As someone who appreciates the scientific process, I am aware that variances in the latte preparation can skew the taste.  As a result, I try to limit the possible variance to the latte making process by maintaining ratios of solids and liquids.  I initially settled on a simple Aeropress process in 2012:

  • Grind approximately 25g to 30g beans. Espresso grind setting.
  • Add approximately 100g to 120g of hot water at 98C. (4x weight of ground beans)
  • Stir hot espresso slurry for no more than 5 minutes.
  • Use Aeropress to extract the coffee into a cup.
  • Weigh recovered espresso liquid.
  • Add 210g to 270g of Horizon 2% Organic cold milk. (3x weight of espresso liquid)

Since 2012, I’ve been experimenting with the variables in making my latte.  The variables include the bean grind, the water temperature,  the ratio of beans to hot water, the extraction time and even the milk ratio.  I’ve noticed is the ratio of hot water seems to extract more flavor but sometimes at the cost of more bitterness.  The bitterness seems to vary which leads me to believe some combination of where the coffee bean originated, how they were dried and/or processed and how they were roasted contribute to this bitterness variation.  The flavor profile also changes to a more earthy, nuttier taste and sometimes a more cocoa imbued aftertaste.  Sometimes higher ratio ends up diluting the latte.  What’s surprising is that the length of extraction time doesn’t seem affect the flavor noticeably but the is a dark brown froth instead of a normal light brown.

Nowadays, with each bag of beans, I first brew with 4x beans to hot water and followed by 3x of milk. My blog posts tends to represent this latte.  Subsequent brews vary between 3x and 6x ratio of hot water and between 1x and 3x of milk.

What I’d like to introduce the use of the coffee aroma and flavor profile wheel from the Specialty Coffee Association.  There are various iterations of this flavor profile wheel.

SCA Flavor Wheel