Re-using yeast cake after cold crash; possible?

I've got a pumkpkin ale that I have plans to cold crash when the primary fermentation finally stops. It's been going for about two weeks. When the yeast finally tucker out, my plans are to cold crash it, rack it straight to the keg, and throw a porter on top of the cake. How cold can I crash the beer, while maintaining the yeast?

Ale yeast will floc and settle out after fermintation, but cold crashing to the low 40's will not hurt anything. A porter will probably work out fine, since there are so many flavors in there anyway. If you have had a good ferment, go for it...

Sounds good to me

I've even stored a cake near freezing and used it two weeks later.

Of course. Commercial breweries large and small harvest yeast in just that fashion.

Wait until the ferment is complete, chill to force any still-active yeast to go dormant and flocculate, harvest after it's been under 40F for a few days.

Note I said harvest the yeast. Simply knocking out into a filthy fermenter onto such a massive amount of yeast is very poor brewing practice.

Cheers!

Bob