Pitching on Yeast Cake

[MrBIP]

Ok, there was a discussion on this a while back, but that discussion and everything else I find is saying that if you pitch new wort on top of a yeast cake, you should start with a light / lower OG beer and then work "up" from there.
My question is this: If I plan to brew the same exact beer, can I rack brew #1 as I'm cooling the wort from brew #2 and then pitch this same exact beer on top of the previous yeast cake? Or should I take the time to wash the yeast and make a new starter and do everything "clean"?

 

[Ozarks Mountain Brewery]

if its the same beer back to back I would think its fine to just pour on top if the temperature is correct. (pay attention to the temp of the used yeast vs the temp of the new wort)they need to be close!
if its a bucket it might be filthy around the top edges, you might need to clean the trub with star sans only on the top edges and get a new clean lid

washing yeast properly takes a couple of days so thats an option but what I do very successfully is after 7 to 10 days in the primary I then pull off into a keg and let it settle at 38 for 5 days, then I pull of into my serving keg and save the clean yeast that fell to the bottom, I then add that to a starter and grow it for the next batch.

seams to be easier than washing

 

[MrBIP]

Thanks, yes, good point on temp, I had not thought of that.
I use carboys, so won't be able to clean that top ring.

 

[newmanwell]

Personally I'd wash and start clean. I've tried some homebrew that was pitched on top of a yeast cake and it wasn't as good as it could have been. Thin and astringent are problems that I've noticed. Pitching rates are pretty important.

 

[The Brew Mentor]

Pitching on the entire yeast cake would be grossly over pitching in most cases.
If you are only doing a primary and staying in there for 2 or more weeks, you can easily wash the yeast and then re-pitch a measured amount of the slurry you've collected in 15 minutes or so.
The dead yeast, hop debris, and trub from the prior batch can influence the flavor of the new batch even if it's the same beer.
There are many videos on this process and I'd recommend following a simple washing procedure.
Good Luck
Brian

 

[social_misfit]

if you are going from a low gravity light beer to a high gravity dark beer imperial stout, royal imperial stout

using the yeast cake more then likely would not be a problem

anything else as stated wash and pitch part of the cake would be better

S_M