Factors contributing to static issues

Grinders are one of the keys to exceptional espresso. Discuss them here.

#1: Post by Bastian987 »

Hi all,
I just upgraded from a Eureka MCI to a Lagom P64. As expected, a very nice improvement in terms of quality in the cup and workflow. I'm very happy with the P64. However, the P64 also has much more static (acceptable with RDT, but still) than the Eureka MCI, which basically has no issues with static at all.

I'm curious what the factors are that lead to the increase in static issues:
1. more static due to higher rpm?
2. higher static due to flat vs conical even besides rpm?
3. more static because of bigger burrs?
4. is it about the coating or material of the burrs?

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Team HB

#2: Post by baldheadracing »

Things typically settle down after a few kilos of coffee have been ground.
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

Bastian987 (original poster)

#3: Post by Bastian987 (original poster) »

Ah interesting, I was not aware about that.

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BaristaBoy E61

#4: Post by BaristaBoy E61 »

I would say, beware of plastics and lack of proper electrical grounding.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

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#5: Post by Tinkershot »

I imagine it has to do with two factors, one being the speed of the grinder introducing more friction between the burrs as the space between them shortens, charging the ground coffee. The second being fineness of the coffee grind particulates in relation to bean roast length. This is why beans with more oil (darker roasts) may not need much RDT if any, and why it may be more helpful with lighter roasts, because there isn't as much oil saturation on the particulates of coffee, namely water introducing surface tension for the ground beans to cling to and less free floating coffee in general. A nicer grinder will likely grind faster with more efficient burrs (and spacing), creating static on the more uniformly ground coffee due to increased electrically charged particals and the volume of air between the grains (fluffy) and subsequently more surface space for it to act upon.

TLDR; Speed introduces more friction and static as a byproduct, more evident on smaller grind size. RDT creates more surface tension for the grinds to cling to eachother, reducing surface friction. Use more or less RDT based on speed of grinder vs roast type. Also why using darker and more oily roasts with RDT on a fast grinder will likely choke it and need to be cleaned more often.
Wine is fine but coffee is divine!


#6: Post by erik82 »

After a couple of KG's it'll be much better. The coffee oil coating on your burrs will cause static to become much less. Same here with my blind shaker that grounds in it are crazy static till up to 2 weeks after cleaning it and after that it's good again.

Still some beans or types of weather cause more static but with my last 5 grinder I've only used RDT for the first 10-20kg and after that it was all fine.