Yet another cold crashing question

[rilo0407]

I know this topic has been discussed a lot recently. Cold crashing is a way to speed up settling, right? I am curious because at a lower temp the density should increase. I understand the principle of density but shouldnt the solids stay suspended longer in colder water? However, when I worked in a water treatment plant the river was always clearer at colder temps but solids were more difficult to flocculate in colder water. I feel kinda stupid because I am a science teacher but it just doesnt make sense.

 

[Bigjuicy]

You are right, density does increase as temperature increases but it is rather slight. As the temperature decreases the yeast goes dormant and starts settling out. Also proteins that are dissolved in solution precipitate and drop out of solution as the temperature decreases.