Yeast Cake = quick fermentation

I pitched onto a yeast cake for the first time Sunday night, actually monday morning. I brewed an Old Peculiar clone, 1.062 OG, pitched it onto a northern English Brown Ale yeast cake of wlp015. As of late last night airlock activity was down to almost nothing, once every few mins. I'll check the gravity tonight. Is a 3-4 day fermentation normal when pitching onto a yeast cake?

The reason I'm asking this question is because swmbo put 2 frozen 2-liters in my ferm tub rather than one which dropped the bath temp VERY low. This coincided with the reduction in airlock activity. Luckily my ferm temps never droped below 63. But just in case I immediatly fixed the bath temp and swirled the fermenter....

Thoughts? General fermentation times when pitching onto a yeast cake?

Schlante,
Phillip

And to think I thought I was beyond asking "newb" questions.... pfffft!

Take a gravity reading, other than that no way to truly tell.

this fast fermentation sounds normal to me.
as there are vastly more yeast cells actively chewing on your wort from the get go (even compared to a hefty starter!), the initial phase does complete more quickly

definitely check for incomplete fermentation, though!