The first place I turn to when seeking new espresso theory is always CNN. Sure theyโve historically gone 0โfer on the espresso tips and tricks, but any good gambler will tell you that that just means they are due. And what do I see amid piles of ongoing impeachment coverage? Why a headline that reads, โScience may have found the secret to a better, and more sustainable, espresso coffee shot.โ Jackpot.
While most articles on brewing better coffee include such revelations as โbuy a grinderโ or โuse fresh coffee,โ usually written by a staff writer with unknown coffee bona fides, CNNโs article is actually more detailed and based on a recently released study by, amongst others, coffeeโs water doctor himself Christopher Hendon (Iโm still waiting on my Peak water filter, Chris). Published yesterday, January 22nd, Systematically Improving Espresso: Insights from Mathematical Modeling and Experiment is a scientific exploration of what exactly is going on when you pull a shot of espresso and how can it be done more repeatably. The answer Hendon, Michael Cameron, and the eight other co-authors came to is, counterintuitively, use less coffee, grind coarser, and decrease extraction time.
General coffee wisdom is to grind very finely for espresso, increasing the total surface area and allowing for a higher yield percentage. But what this new research presupposes is: maybe it doesnโt? According to Hendon et al, by decreasing the total coffee bed size by reducing the amount of coffee used, thereโs more room for water to get into the portafilter and hang out for longer, thus brewing the coffee more and increasing extraction.
For the purposes of consistency and repeatability, the paper suggests a coarse grind, which leads to a much faster shot time, between seven and 15 seconds total. Per the researchers, grinding finer is inherently more unpredictable, with an โinhomogeneous flowโฆ resulting in poor reproducibility and wasted raw material.โ
Beyond the consistency, the benefits touted by this new espresso recipe are twofold: itโs faster and cheaper. The shorter total shot time, it is argued, lends itself to a quicker drink turnaround time, and by using less coffeeโaround 25% per shotโCNN estimates coffee shops would save over $3,600 a year.
Hendon does note that viewing the quality of an espresso shot purely through the lens of extraction yield is reductive. What makes the traditional espresso shot harder to reproduce also appears to be what adds to its overall complexity. Some, like Zachary Gordon-Kane of Atlanta’s Brother Moto tells CNN, want a โthicker, more viscous experience, with more punch and flavor.โ
Itโs no doubt an interesting new theory on espresso extraction and there is no doubt enough here for all you spro bros to argue about on your coffee forums or your podcasts or to unsuspecting customers who just want their latte thanks. And if you do choose to engage in some insprolectual combat, make sure to gird yourself with words like โsolubilityโ and โvarianceโ and maybe โspatial inhomogenization.โ Iโm not sure that that last one actually means anything, but it sounds technical. Or you could just do what I do: drink filter coffee.
For more information, Systematically Improving Espresso: Insights from Mathematical Modeling and Experiment can be found here.
Zac Cadwaladerย is the managing editor at Sprudge Media Network and a staff writer based in Dallas.ย Read more Zac Cadwaladerย on Sprudge.
Top image ยฉ Adobe Stock/Antonio Guillem