I plan on brewing a porter this weekend and want to put it on the yeast cake from a pale ale that is currently in my primary. I've read several different threads on this and it looks pretty straight forward. However, the one thing I never see mentioned is whether or not the wort needs to be aerated?
Do you aerate the wort as you would on any other batch? If so, should the aeration be done before it is poured onto the cake or can it be done after?
A lot of that stuff in the "cake is going to be hop matter, dead yeast, and other junk. to reduce this you can put it in sanitized container with a little bit of the pale ale and swish it around. Let it sit and decant the beer looking stuff into the fermenter. The yeast that is still suspended in the beer is the strongest of the bunch and should get going pretty fast.
I just used this approach for the first time 2 weeks ago. I went from a Pale Ale to an Oatmeal Stout and so far everything has gone great.
__________________ Brewing Next: Stout Fermenting: APA with Pils and Saaz, German Pilsner, DunkelWeizen Kegged: APA
I just pitched a porter onto a pale ale cake a few days ago. What I did though was put the cake into a sanitized container, clean and sanitize the primary then put the wort and the proper amount of cake back in (using an online yeast calculator). In less than 24 hours it was going crazy.
I didn't bother washing the yeast. Some recommend doing it if you are going to save the yeast but since I wasn't waiting I didn't bother.