How to reuse yeast cake

From the I Love Apfelwein thread:

jmp138 said:

The yeast cake left over when you rack your beer from the fermenter is some of the most viable yeast around. Lots of brewers who need a really high pitching rate for a big beer will brew a "small" beer, around 1.040 starting gravity, ferment it out, and then throw the wort from their big beer on top of the yeast cake from the small beer.

Some of the most vigorous fermentations and best attenuation I have had have been from using a previous yeast cake.

As far as off flavors, as long as you are using the cake from a fairly neutral ale, I don't see that you would have a problem.

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What is the process to reuse the yeast in this case? Does the carboy need to be sanitized in any way? Does the Krausen need to be cleaned out? Or does one rack off the cider and pour ingredients for a new brew directly into the "dirty" fermenter?

Doesnt seem consistent with the careful sanitation needed in brewing...

Are you making apfelwein or beer? If apfelwein, a yeast pack is like $0.70 - better to just buy another pack and use a clean carboy.

If beer, then do exactly what you quoted says - don't clean/sanitize the inside of the carboy (it was clean/sanitized when you took the beer out, so it's still clean/sanitized when you add the new beer in).

I've never done Apfelwein . But I've dumped a fresh IPA on a Safale -05 cake with no problem. It was pretty impressive.

Euler's Identity, very nice. Brewer and a math teacher?

do you just dump the new wort on top of the cake,or do you have to mix?? how many people do this? Do they have to be certain gravity beers? More on this please!

Here's what I did.

Made a beer. Used S-04, whoop de doo.
Then I racked the beer, bottled it, whatever. Plan was to quickly make another beer and just throw it in the bucket on the yeast cake and see what happens. Well, as we know the best plans of any brewer often go to ****. So I had the bucket with yeast in it sitting in my cold cellar for a month. It had a lid on it and airlock, so I wasn't really concerned.

So I finally got around to making that beer, and figured "what the hell, it's better than cleaning out this bucket" and I put the beer in it. A pack of S-04 is what, $3? Look at me, saving $3! Normally I aerate with a fish tank thing, but this time seemed not the thing to do, so I just splish-splashed the wort around as it siphoned out on to the old cake. This is boring so I do this with one hand while trying to hook up my phone to some speakers with the other. It never works and I never remember to play the music first. But I digress.

When it was done I just stuck the lid on it and forgot about it for a month.

Just literally pulled the first glass of it out of the keg an hour ago, and mmmmmmm nice.

The only thing that sucked was cleaning the krausen from the first batch off of the bucket. That crap was stuck on there like white on rice.

So yeah, long story short - just make a new batch and toss it on the old cake. No mixing required, that shizznit is going to go bananas and mix itself over the next couple of days. Oh, and overpitching concerns are for serious brewers, of which I am not one.

Basementboozer00 said:

So, say for example you had a yeast cake from a "lite" beer, what would be a good choice to pour on top of this cake? And heres another stupid question, would I pitch more yeast, or just let the cake do it's thing ?

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I found it's better to skim a bit of the cake off, dilute a bit with water, and pitch that instead. Like a 1/4-1/2 cup of it. Search for this, there's lots of input and photographic instruction.

MrMalty has a setting for pitching slurry - this is what I used with great results. Pitching a new beer on an entire cake of S-04 left me with a beer that tasted like bread - I had to dry hop with citra to fix it. That post I have right above yours? All lies once things settled down. That beer just wasn't as good as it could have been, and I think less yeast would have been the way to go.

Use Mr. Malty calculator to find out how much volume of the cake you should use.

Recently used a portion of a Nottingham yeast cake from a blonde ale for an 8.5% old ale, here was my procedure:
1. While mashing in the old ale, I transferred the blonde ale to secondary.
2. Scooped out the calculated amount of yeast cake and placed into a sanitized covered glass measuring cup.
3. Cleaned out the primary for re-use (I only have one).
4. While pouring the old ale wort into primary I added the Nottingham yeast cake.
5. Used a blow-off tube set up and put the primary into a larger kettle to catch any messy krausen that might leak out.

Had active fermentation within a few hours, lid was bulging the next morning.

I usually stage a double brewday to reuse a cake.

Brew 1st batch, chill till chiller stops, place in ferment chamber to cool to pitching temps

Brew second batch, chill to pitching temps.

Rack brew off cake to secondary, sanitize a ladle and scoop 1/2 cake and pitch into 1st brew

Wipe krausen ring out of dirty fermenter with starsan soaked paper towels and then rack 2nd brew on the rest of the cake