Wort on top of a Yeast cake?

[DNKDUKE]

Brewed a Doppelbock that turned out to be a disaster
https://www.homebrewtalk.com/showthread.php?t=601386

So I am going to brew this again - this time with the CORRECT INGREDIENTS and would like to use the yeast. The fermentation has stopped and so I was going to brew the new batch and rack it on top of the yeast cake after draining that carboy.

Question 1: There's alot of hopps trub in the carboy, should I 'wash' this yeast in the carboy first to remove the hopps?
#2 Can I just rack ontop of the whole shebang? Will the trub affect the flavor?
#3 It's sitting at 55degF right now...should I warm it a little - rack the new wort on to it - and then take it back to 55deg?

Thanks.

 

[flars]

Pouring a new wort on the entire yeast cake from the previous beer would be a massive over pitch. It would be better to harvest the yeast without washing/rinsing. Check out this thread on harvesting.
https://www.homebrewtalk.com/showthread.php?t=579350

If you are using carboys the procedure to get cleaner yeast is even simpler. Swirl up the remaining contents of the fermentor. Lay the carboy on its side blocked to prevent rolling. Wait about 15 minutes until you see a thin layer clearing at the top. Pour into a couple or three pint canning jars. You'll be pouring off mostly beer and yeast. After a couple of days to compact in the refrigerator you will be able to estimate the number of yeast cells harvested. One of the pint jars will probably be enough yeast for your next brew.

 

[SoggyWood]

I just kegged a Saison that was simply dumped on a cake of WLP500/530 blend and it turned out awesome.

Don't overthink it.

 

[Bauzer]

One thing I have found on these forums, is you can get every single answer to every single question. I've heard some crazy things in my homebrew club that I just wouldn't have considered doing, and they swear by it.

I can't knock flars' response though, as I read something similar before, and took it as gospel. But I found yeast washing is time consuming and I find I lose motivation really fast (I usually just make a starter and pour off some to build up later instead of this).

So this is just based on some of the conversations that I've had with our homebrew club, and its just another side to things. In the end, do what you think you are comfortable with. Its all a learning experience, and we all have different experiences.

I haven't heard about a situation regarding a lot of hops in your trub, but I'd figure this would affect your taste consider you say 'a lot'. If you didn't, then you could pour the wort on top of the yeast cake/trub fine. I know a guy who swears by this and I have tried his beer and it didn't suck.

If it was me, and the beer turned out terrible, I would just start it all from scratch. Though if you didn't save any yeast, then do flars' technique to harvest the yeast, and build a starter up. you may need to build it up 2 or three times depending on how much you get.

If you decide to just roll the dice on pouring the wort on top regardless, I'd try and get the carboy near the same temp as you would for 'pitching temp', just so you don't shock them too much with the different temps.

 

[DNKDUKE]

Pouring a new wort on the entire yeast cake from the previous beer would be a massive over pitch. It would be better to harvest the yeast without washing/rinsing.

What is slightly confusing to me is that pitching ontop of a yeast cake used to be a common practice.
Did something change?
Also, everyone talks about the woes of an UNDER pitch but no one talks about an OVER pitch...what's the downside?
Having asked all these questions, I'm still concerned about the hops in the yeast cake having an affect on the new beer....this is supposed to be a Doppelbock not an IPA Doppelbock.

 

[flars]

Off flavors can be the downside to an over pitch just as off flavors can be a downside to an under pitch. With some yeasts an under pitch will produce off flavors that are desirable in some styles of beer. The same yeast with a high pitch rate, but not massive, can change the resulting flavor to what the brewer prefers in the style. (I'm thinking of a Hefeweizen brewed with WY 3068. Phenols over esters.)

Since this is a lager the cleanest flavor profile possible will give you a better beer. Harvesting the yeast will remove some of the hop debris because it will settle out faster than the yeast in the fermentor. If you pour into quart jars you can repeat the harvest by allowing a few more minutes of settling time and pouring off again.

You might be able to harvest enough for the next lager but I would plan your brew day for after completing a starter with the harvested yeast.

 

[Mainer]

This summer I did three saisons using a single yeast cake of WY3711, and didn't wash in between. All three came out fine. I wouldn't worry too much about the trub, as long as you don't plan to leave it on the trub too long. I racked all three of mine off to secondary. (Two of the three had fruit additions in secondary.)
However, @flars makes a good point: you're using a lager yeast, so if you want a clean lager-y profile, that will be way less tolerant of off-flavors than my saisons were.

 

[Cavpilot2000]

I think it is nearly impossible to overpitch a lager (I brew a lot of lagers - about 50% of my brews).
That said, I would worry more about the hops in the cake than the amount of yeast, especially for a Doppelbock (being that hops are generally close to undetectable in a Doppelbock). I generally never repitch on a yeast cake that has been dry hopped.

Did you dry hop the last batch or just carry a lot of trub in from the kettle? I ask because I wonder why on earth you would dry hop a Doppelbock.

Honestly, I would probably pull a decent sample from the carboy and use it to make a nice, big, fresh (un-hopped) starter.

 

[DNKDUKE]

Cavpilot,
During the boil, it seemed that ond of my hop socks tore and dumped an unusual(for me) amount of solids in the wort.

 

[Bauzer]

Ah ****. Ok
Balls.
I really hate to say it man. But I'm backing up the yeast wash. Or if you are ok with the cost. Buy new yeast.
Additional reason.. we like to narrow down why we liked something. Or hated something. This would give too many variables to focus on.

 

[Bauzer]

Ps.
I would otherwise say **** it and pitch on the cake. Lager style especially needs lots o yeast.

 

[DNKDUKE]

Ah ****. Ok
Balls.
I really hate to say it man. But I'm backing up the yeast wash. Or if you are ok with the cost. Buy new yeast.
Additional reason.. we like to narrow down why we liked something. Or hated something. This would give too many variables to focus on.

Bought new yeast. I want my first lager to have no variables.
When I harvested, I got very little yeast and a ton of hops...maybe I didn't swirl enough?

 

[Bauzer]

Perhaps. After the second or third time trying to do yeast capture and washing.. I was done. Make big yeast starter and pour some off in a sterilized container for another time (especially if it turns out great and you are happy with the yeast!!).

Hope this run goes better!

 

[DNKDUKE]

Just started a new starter (HA, I KILL ME...)

 

[Mainer]

I hate to waste yeast, so if I feel like it's not right to brew with for some reason, sometimes I'll harvest from primary and use the yeast to bake bread. It's not bad.