Really quick fermentation!??

Good morning

Racked a Chocolate Porter on top of a fresh yeast cake from a cream ale.
(Racked Cream Ale to a secondary and within a few minutes racked the cooled Porter from boiler right on top of the Cream ale Yeast Cake)
Within a few hours i had visible fermentation with a layer of Krausen beginning to form. This morning it looks like the fermentation is beginning to wrap up..the Krausen is dissipating.
Is this quick fermentation normal when pitching on top of fresh yeast cake?

I've heard it's quicker than just pouring a packet of yeast in but Jeez!

Yes, that's normal. By massively overpitching, you're removing the time normally taken up by reproduction. You're also removing most if not all of the esters so beloved of ale yeasts.

Even when pitching a proper amount of yeast, an ale ferment can be over in 24-36 hours.

Just let it rest for a week so the yeast can metabolize stuff like diacetyl before you rack it.

Bob

Thanks Bob - that's what i figured. I guess for my delicate ales i should not use this technique due to the lack of ester production. With the Porter it's probably not as noticeable...
Thanks Again!!
I love this hobby and the people who are so helpful!