[lfuller]

As I've seen several comments on this here - people have used spritzes of water to reduce static when grinding coffee for years, but the interesting part of this study was the finding that beyond reducing static, adding enough water prior to grinding actually reduces flow rate and increases extraction by preventing the creation of coffee clumps / aggregates.

So it confirms the anti-static properties that everyone already knew, but has interesting implications for increasing extraction without changing any other variables.

[c0pium]

It also bears pointing out that the amount of water needed to achieve these anti-clumping effects is probably twice what people are using following existing RDT (water spraying) methods.

[searealist]

WDT was already super popular, so the declumping properties aren't very useful. And the static issue is mostly limited to non-traditional light roasts.

[stouset]

The clumps in question are electrically bound, so WDT likely won’t do much to break them up.

[jbverschoor]

Is this the same when you try to mix coco powder with milk? You need to first use a little bit of milk or water to get it to form a sauce. After that you can easily mix it with milk

[searealist]

Coffee grounds aren't neodymium magnets.

[stouset]

No, but the clumps in question are small and are unlikely to be broken up by gentle stirring.

[searealist]

You are an expert on this new concept you just learned of the same day.

[stouset]

I did read the paper, and I am generally familiar with the physics of charged particles.

And of course I caveated everything with “likely” and “unlikely”, to hedge against misunderstanding. What else would you like me to do?

[checkyoursudo]

I am not a coffee historian or even very knowledgable, but I thought that light roasting is the more traditional (even ancient) way of making coffee and that the roasting has gotten darker over time. Not so?

[AdmiralAsshat]

"Ancient" coffee roasting was probably very uneven. The beans were often just roasted in a skillet over a fire, not unlike toasting pine nuts. If you've ever tried toasting pine nuts on a stove, you've gotta be very careful with the heat control and keep the nuts moving frequently, or else you'll have some that are still blonde and some that are bordering on burnt.

[xethos]

> For instance, lighter roasts have more internal moisture than darker roasts, and the latter is more prone to clumping

I suspect you might have it backwards regarding the issue being limited to non-traditional light roasts.

[searealist]

Lighter roasts channel more than dark roasts and also make more of a mess coming out of a grinder (more static).

[noSyncCloud]

It says in the linked article that darker roasts have less internal moisture content (obviously, they've been roasted longer) and therefore produce more static/clumping.

[searealist]

It does not say dark roasts have more static, and in the real world light roasts are much harder to brew.

[laweijfmvo]

I imagine that the clumps being discussed here are much smaller and much more electrostaticly attached than a NDT can deal with.

[searealist]

WDT would be an extremely obvious thing to test in both the original paper as well as the follow-up videos by Hoffman/Hedrick. It is absent in all three.

Also note that Hoffman found RDT only helped in _some_ grinders. WDT also only helps with some grinders.