A Volcanologist and a Chemist Walk Into a Coffee Bar...

[chromedome]

...and write a paper together.

 

Okay, the chemist has actually done studies on the mechanics of espresso brewing in the past, but this time he looked into the savvy barista's habit of lightly spritzing the beans before grinding to see if he could validate a scientific reason for doing so. The experiments were successful, and the volcanologist took away some useful insights as well. First link is a layperson's explanation, second link is the underlying paper.

 

https://arstechnica.com/science/2023/12/study-why-a-spritz-of-water-before-grinding-coffee-yields-less-waste-tastier-espresso/

 

https://www.cell.com/matter/fulltext/S2590-2385(23)00568-4

 

 

[dcarch]

1 hour ago, chromedome said:

...and write a paper together.

 

Okay, the chemist has actually done studies on the mechanics of espresso brewing in the past, but this time he looked into the savvy barista's habit of lightly spritzing the beans before grinding to see if he could validate a scientific reason for doing so. The experiments were successful, and the volcanologist took away some useful insights as well. First link is a layperson's explanation, second link is the underlying paper.

 

https://arstechnica.com/science/2023/12/study-why-a-spritz-of-water-before-grinding-coffee-yields-less-waste-tastier-espresso/

 

https://www.cell.com/matter/fulltext/S2590-2385(23)00568-4

 

 

 

 

What I don't understand,is the following what they say, "--------a single squirt of water to coffee beans before grinding can significantly reduce the static electric charge on the resulting grounds. This, in turn, reduces clumping during brewing, yielding less waste and the strong, consistent flow needed to produce a tasty cup of espresso----"

 

Isn't it basic physics that similar static charges repel each other therefore less clumping? as in the famous physic 101 experiment of your hair rising if you get yourself charged by static electricity?

 

dcarch

 

 

[chromedome]

Unsurprisingly I was not involved in the actual research, but my mental picture was of the charged coffee particles clinging together like clothes in a dryer (obviously, a dryer without a Bounce sheet). Dampness inhibits static charge, so it all seemed logical.

[Deephaven]

Didn't read the link yet, but the Ross droplet technique is super common in particular to stop the static mess on the grinder.  I have a negative ion generator built into the spout of mine greatly reducing the need.  As for better espresso, that part is new to me.

[haresfur]

I was a volcano obsessed kid and love the article. 

 

I don't understand how spraying the beans before grinding could work with a commercial grinder with a reservoir for the beans. I do know my main hangout adjusts the grind many times a day to keep the flow correct.

[Deephaven]

Hoppers are going away with a preference for single dosing.  Of course there are other mechanisms to single dose with a hopper, but none work as well as a dedicated setup 

 

As I stated above, the static is where rdt really helps.  The article states it reduces clumping but most good coffee shops are using grinders that really don't clump.  I have a pretty cost effective 83mm burr grinder and it never clumps.  Even if it did wdt solves that and is a much better cure for clumping and poor distribution than using a water spritz.  

If wdt is new term, it is Weiss distribution technique where you "comb" your grounds before tamping to break up any clumps.  Typically done with a cork and 4 acupuncture needles or a commercially available version of it.

 

So if you grinder is covered in staticy coffee use water otherwise for clumps give it a stir.  

 

[weinoo]

17 minutes ago, Deephaven said:

Typically done with a cork and 4 acupuncture needles or a commercially available version of it.

 

Before or after they’ve been used in treatment?

[Duvel]

5 hours ago, weinoo said:

Before or after they’ve been used in treatment?

I‘d say for the acupuncture needles it doesn’t matter, and for the cork - if used as a household remedy for explosive diarrhea - better before …

[Deephaven]

Ha, was just giving you the cheap way of making one.  Just buy a wdt tool.  Sometimes they are called puck rakes.  I bought mine on Etsy.

[Laurentius]

I tried this technique today.  Marginally reduced static cling, and no change in flavor.

 

I just brush out that which clings into the filter.

[Deephaven]

Yep, that is all that it does.  Of course, if you have a grinder with a lot of static retention it may improve the flavor of the first shot of the day if you have a .5 gram of coffee from yesterday stuck in it, but that is not a function of the water but of having the wrong tool for the job.

[Deephaven]

Adding an anti-static plasma generator (false name, ion generator really) to your grinder is a better idea than spritzing IMO.

[paulraphael]

My grinder (for brewed coffee) is a static factory. I've used a little atomizer for this technique for a couple of years now. It works. I mostly have to do in the winter when the air's dry.