Manufacturing guy-at-large.

Seth Bunsen's Coffee experiment

Added on by Spencer Wright.

OMFG this is great! 

Basically, this guy did an informal (but blind, controlled, and apparently statistically serious) experiment to determine which variables affected people's feelings about a cup of coffee. The short of it:

  • People slightly prefer spinning-blade grinders to burr grinders
  • People actually prefer Aeropress coffee to drip brew. 
  • Seth Bunsen is awesome. 

A few takeaways (emphasis mine):

My longest running experiment centers on coffee grinders. A common belief among coffee pundits is that good coffee depends on good grinding. Specifically, coffee ground with a burr grinder purportedly tastes better because it grinds the beans more uniformly and doesn’t over-heat the grounds like traditional blade grinders. The experiment I setup tested this claim by brewing coffee using a burr grinder or a blade grinder and scored which of the two cups subjects preferred...Based on this analysis, subjects did not show a statistically significant preference to coffee brewed from a blade grinder or burr grinder. Therefore, I opted to save a few hundred dollars and not invest in a burr grinder based on these experiments.


Another variable I was interested in understanding was the impact of different brewing methods on flavor preferences. I wanted to know if house guests preferred coffee brewed via drip-extraction versus coffee brewed with the Aeropress. I setup my experiment as previously described and scored the number of house guest who preferred each brewing method. The objective of this analysis was similar to the burr grinder experiment, but this time I wanted to compare preferences between two different brewing methods...I observed that 15/20 or 75% of subjects preferred coffee from the Aeropress...Thus, there is reason to believe that the Aeropress may, in fact, produce better tasting coffee than drip-extraction.


I’ve examined other coffee variables using a similar experimental approach and found only a few factors that had any measurable effect on coffee flavor in isolation. For example, variables like bean freshness or bean purveyor has little effect on flavor...Until I obtain convincing evidence that support investing additional money in brewing accouterments, I see little reason to deviate from this system. In the words of Carl Sagan, extra-ordinary claims require extra-ordinary evidence.

This is exactly the kind of study I want to do with wine. I'd also love to expand upon Bunsen's coffee experiments to include Moka pot, French Press, and - why not - Folgers. 

With thanks to Marco Arment for the link.