Pitching wort on top of yeast cake

[DonT]

I searched around but couldn't find exactly what I was looking for....
I'm brewing a NEIPA tomorrow using 4oz hops for DH (4oz in WP too) and Cosmic Punch. Also adding some Phantasm... My plan is to brew again using the same grain bill and hop schedule (using different hops) on the day I'm planning to keg batch #1, and just racking batch #2 on top of B#1 yeast cake.
I've yet to do this so I guess I'm looking for some insight on how that will work... will the old hops affect the new batch? This would a massive overpitch... any issues with that? Am I overlooking something?
I can't dump the yeast, I use a Spike Flex+. My wort chiller won't get it below 80F usually, but the yeast cake will be at ~40F... how will that affect things?
My glycol chiller can bring that down pretty fast though....

Thanks for your input!

 

[Joshua Hughes]

It will be fine

 

[user 338926]

There's another thread I just read yesterday where a guy details what he does. If I can find it again I'll link it.

90

(Edit) I can't find it. Not even sure which forum it's in. He talked about and even had pictures of going directly from the kettle into a 15 gallon corny keg in which he had both fermented and served from. I want to say he scooped out half the yeast cake first but that may have been another person said that. In any event, they preferred it to other methods.

 

[homebeerbrewer]

I do that often. I've used the same yeast cake for as many as three batches without issues. I would suggest to try to get the wort and yeast cake close to the same temp before pitching. In my experience, the yeast seem to take longer to get started after being shocked by the temp difference. When they're close in temp, they get to work immediately.

 

[DonT]

Thanks Guys! I was pretty sure it was going be ok... since I've never done it before, just wanted to be sure...

 

[scogan]

Thanks Guys! I was pretty sure it was going be ok... since I've never done it before, just wanted to be sure...

I did it a few brews ago, it took off fast and finished in 36 hrs.I did need to clean the blow off tube a couple of times ! Can’t remember if there were hops in it or not.I suspect there will be a few who say hop debris makes it in advisable , but those of us that serve from the fermenter worry less about hop contact time.I think when I asked about it recently ( so search my posts if you need the original thread )someone said about a quarter of your trub is about ideal.

 

[seatazzz]

I've done it a few times, but mostly I just jar up the slurry after racking into the keg, refrigerate it, and use it for the next brewday; I'm not often brewing two beers subsequently that use the same yeast. +1 to what was said above; scoop out about half of the yeast cake, unless your next beer has a pretty high SG (1.065 or higher). There's differing schools of thought on overpitching, but I try to avoid it if I can.

 

[Whisky River]

I’ve done exactly what you described in a Flex Plus and it went alright, sort of. For me the hops weren’t the issue but the second beer over attenuated and turned out very thin, probably due to the massive overpitch. I’m currently trying it again with an IPA to see if that first one was a fluke or if it was really due to the over pitching.
Please let us know how yours turns out so we have some more data points.

 

[mac_1103]

Why would overpitching cause overattenuation?

 

[Whisky River]

Why would overpitching cause overattenuation?

I don’t generally speculate. I shared my observed experience to help inform the OP of potential issues that may or may not arise as a result of using this technique.

I will add that the wort I pitched onto the yeast cake was for a brown ale that should have finished around 1.015 leaving some residual sweetness. The fermentation was instant and vigorous as others have reported and likely resulted the thin watery mouthfeel that is commonly associated with over pitching.
This beer also attenuated just passed the high end of the published range for the yeast, which I believe may have contributed to the dry and thin taste of the finished beer.

 

[mac_1103]

So IOW, it didn't actually overattenuate?

 

[Whisky River]

So IOW, it didn't actually overattenuate?

Since you clearly don’t have anything better to do on a Saturday afternoon than troll around here and try to start an argument, I’ll humor you with a response. Depending on the level of your reading comprehension you may or may not have been able to figure out that both things happened to the batch of beer I was describing. It had the commonly reported thin character associated with overpitching, and it over attenuated. If they were both caused by pitching onto the yeast cake we may never know.
Enjoy your weekend

 

[mac_1103]

Sorry dude, but no I wasn't able to figure out that "both things happened." IMO, overattenuated means something different than you seem to think it means.

 

[homebeerbrewer]

This beer also attenuated just passed the high end of the published range for the yeast, which I believe may have contributed to the dry and thin taste of the finished beer.

I don't understand. You say it overattentuated, but finished passed the high end of the published range. Can you clarify that please?

 

[JohnDBrewer]

I pitch on my yeast cakes all the time. Never let a good yeast cake go to waste, especially for lagers. I've never experienced over attenuation, but if you cannot control your fermentation temp, it can remove some malt character and subtle favors. So ferment at the lowest range the yeast can handle, which means getting your wort down to that temp when putting it into the fermenter since the fermentation takes off so fast. For lagers, I make sure the ferm temp is 48 degrees and keep it at that for the first week. I use a freezer with a temp control on it as a ferm chamber. I also run a fan in the ferm chamber as I believe this helps level out the temp fluctuations.

 

[Dland]

I've gone up to 11 batches on one pitch so far, and even then when I cleaned out the fermentor I saw I could have kept on going. I brew in a stainless conicle, so I can't see what is going on without breaking the fermentor's seal.

If pitching on yeast cake repeatedly, keeping it close to fermentation temp is important for viability. It is good to oxygenate the new wort to help the yeast get going again. Trub & yeast solids should be removed regularly.

This works best if brewing regularly, yeast cake viability seems to go down if left more than 2-3 weeks without new wort.

I've never noticed difference between similar beers brewed on first pitch vs ones on developed yeast cake, except the fermentation gets going faster and works out sooner after a couple batches.

 

[faroutadventure]

I use old yeast all the time. Works great. Get strong fermentation. Just make sure and keep everything sanitized and you should be fine.