After attending the get together in SF, I've begun cupping, but I have a simple question: I grind a coarse grind, add the water on top and I get no crust. The grinds just sink to the bottom.

How do I get a crust? Or does it matter? Other than that, it's going well and quite useful.

Thanks,

dan

The crust is not all grinds - it's mostly a sort of foam with fines mixed into it. The majority of the grinds end up sinking to the bottom. Is your water hot enough and your coffee fresh enough? I'm just throwing out wild guesses because I've never seen a coffee prepared for cupping that didn't have a crust.

The coffee is very fresh and I am using 208 degree water. From a hot pot. Maybe that's the problem.

Phaelon56 wrote:The crust is not all grinds - it's mostly a sort of foam with fines mixed into it. The majority of the grinds end up sinking to the bottom. Is your water hot enough and your coffee fresh enough? I'm just throwing out wild guesses because I've never seen a coffee prepared for cupping that didn't have a crust.

This is incorrect; when cupping, all the grounds are in the crust, you can see this if you use a glass cup. It should work fine with coffee direct from the roaster or up to a week old, although SOP is to cup from 8 to 24 hours post roast.

One possible problem is temperature. Use 208F water if you decant it into a jug, and then carry the jug to the cupping table to pour. This is the preferred alternative. You can also fill the cups directly from the water heater, but then it must be set at 195F (assuming you have one that follows the Zojirushi standard of 208F for black tea, 195F for oolong, and 175F for green tea).

The other problem is too much or too little agitation. Don't dribble the water into the coffee, pour it with authority. Move the pitcher as you pour (or the cup, if you are filling directly from the heater), so all the grounds get soaked; but do not swirl the cup or stir.

If you did all this, and still didn't get a proper crust, I'm flummoxed.

And different amount of crust coffee floating on the cups can be an indicator to primarily judge the quality of one cup than the others? Or it's just because the coffee's roasted too dry, or with different level?

I've noticed that extremely lightly roasted coffees (even lighter than a standard cupping roast) will tend to have a sinking crust. I'm guessing it's due to a denser cell structure and a greater level of remaining free-water molecules.

What roast level are the coffees at?

I cupped the *bucks (xmas blend, didn't know roasted date) one with a couple local pro ones (maybe FC or FC+).
*bucks' beans looked much darker, however, the crust sank more quickly.
I didn't know the roasted level, just only looked at the outside color of the beans.

I always think that the darker one should sink slower, maybe I'm wrong about this.