Why does cold crashing work?

[Bellmer]

That could have something to do with cold crashing as it relates to coconut, but coconut is just an example solid. Cold crashing also works with yeast, trub and hops.

Right. I was just addressing the floating coconut mentioned in the original post. I think Mylo's observation is a likely explanation of why it drops out.

[stadelman]

I think Brandon has the answer.

When an objects temperature decreases, it's density increases and it becomes less buoyant. Take a lava lamp as an example. The light bulb heats up the wax in the bottom of the lamp and the wax rises. When the wax reaches the top it cools and sinks.

My thinking was that the density change of the solid would be offset by the density change of the water, but I no longer believe that to be the case.

[BDawg]

Are those African or European coconuts?

I'm with those who say it's the nucleation points -- cold beer holds more co2, so there is less coming out of suspension. Less co2 sticking to them is making them sink. Warm it back up, more co2 comes out of suspension, more coconut floats.

[stadelman]

There's any easy way to prove this one way or the other. I'll do an experiment... put some coconut in room temperature water, wait for it to get well saturated, see what happens, if it continues to float, I'll cold crash it and see what happens. I'll report back with photos.

[BayouBrew]

a^2 + b^2 = c^2
Somebody had to drop the pythagorean theorem around here.
It's completely unrelated to buoyancy and density, but it sounds sciencey.