Pitching a second beer on top of a used yeast cake

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I've seen some older discussions on this topic but wanted to bring up my specific idea.

I'm brewing a Helles Bock (Maibock) with expected OG of 1.067
Will be using WLP 833 (German Bock Lager Yeast) and make a BIG starter

I then plan to brew a Doppelbock with expected OG of 1.095 - 1.1
The idea is to rack the Helles Bock and then pitch the Doppelbock right on top of the yeast cake and let it ferment away.

I've never done the pitching a new wort on top of a used yeast cake, but have some Homebrew buddies who have, and typically turns out well.

Any advice on this idea?
 

Jag75

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people always tell me it's TOO big a pitch when i do.... :mug:

Technically it can be . Depending on the OG . Most of the time too big is fine . Some brewers out there know how much they need and pull some yeast out and leave behind the desired amount. It's still a crap shoot . The only way to know for sure is to count cells . It's a really good way to save $ on brewing, especially commercially.

I know saving $ on brewing is somebody's specialty 😉
 

bwible

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I always re-use yeast by re-pitching on top of the yeast cake from the previous batch.

I follow a couple common sense rules:
- Work light to dark, weak to strong, less hoppy to more hoppy. Same way beer judges judge beer.

For example, I have a 1056 right now that I plan to make 4 beers from. I split the pack and made 2 starters. The first starter went into an Irish Red Ale. When I move that, a dry stout will go on top of that. The second starter went into an APA. When I move that, an IPA will go on top of that.

- Beware of flavor carry overs. In my case, I split my starter because I didn’t want the roasted grains from the stout in the American beers and I didn’t want the American hops in the Irish beers.

Helles Bock into a Doppelbock is great.

There are people who collect and wash the yeast. I can’t comment on that because I never did it.
 
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Nathan Graen

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I'm planning the exact same thing right now. Dr Hans' has a video where he pitched on the same yeast cake for a year. I don't have a conical to take some of the trub out each time, so I'm only planning four different beers.

My small concern is reusing after the Maibock, as it is a higher gravity beer, and I hope the yeast isn't too stressed afterward.
 

odie

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I would suggest having a method to ensure your wort going into the fermenter is as trub free as possible.

I personally use a 200 micron bucket strainer. My yeast cake always comes out super clean.
 

GrowleyMonster

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I have done that with excellent results, the only issue is that with a really big beer, you end up definitely burying your spigot with the second batch. I cope with this by doing a swirl when fermentation slows down, carefully tipping the fermenter back a bit away from the spigot and bracing it in position so it doesn't accidentally get knocked over, and letting it settle at the new un-level level. If left undisturbed long enough for the yeast cake to firm up, I can then tip it slowly back to vertical and have only a little sediment caught in the spigot to be concerned with on kegging (or bottling) day, and I can just use the spigot normally. There is still a bit of sediment in the output at the very end, if that is an issue. Another thing I sometimes do is to rack into a purged secondary using closed loop transfer. I get some settling in the secondary but only a very thin and manageable cake, so I can bottle or keg from the spigot. My fermenters are Big Mouth Bubblers, all with spigots.

If you don't even use a spigot, it is not an issue. With big beers, I don't think you have to worry too much about over-pitching. Introduce the wort gently so you don't completely and massively stir up the cake and you should be just about right there somewhere in the very wide ballpark.

Whenever I poured right onto the existing yeast, I always tried to brew same day I empty the fermenter so the yeast doesn't sit there bored with nothing to do except slowly vegetate and die off. In case that is a thing.
 

Beermeister32

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I’m sure everyone has done it, probably for centuries. Probably every brewhouse too.

Just make sure you are pulling from a yeast cake that isn’t laden with a huge amount if trub and break material as that will carry over to the new beer. Worse case that can begin to cause off flavors. I usually dump off my full yeast cake to a sanitized 2-liter plastic Snapple bottle, refrigerate and save it for later to determine if I want to re-use the yeast cake. Before I re-use it, this allows you to taste the previous batch first so you aren’t re-using a cake that previously made a poor batch.

You can take maybe a third of the Snapple bottle cake, give it a spin on a stir plate for a day or two with about 1 or 1.5 liters of starter wort for a 2 liter re-pitch. Chill, decant and proceed. You will have a strong fermentation.
 
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adguyer

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I would suggest having a method to ensure your wort going into the fermenter is as trub free as possible.

I personally use a 200 micron bucket strainer. My yeast cake always comes out super clean.
Can you explain how you wash the yeast out of the whole cake?
 

odie

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Can you explain how you wash the yeast out of the whole cake?
I don't wash the cake. The cake is already clean.

You let the kettle sit a couple hours to settle & clear. Place a 5 gal bucket strainer insert (micron rating of your choice) on top of your fermenter bucket. Open the kettle spigot and let the clear wort run thru the strainer into the fermenter. About 4 gals is above the spigot. There will be about 1 gal of wort/trub left in the kettle below the spigot. Dump the remaining kettle bottom into the strainer, sludge, hops and all. Only clear wort will drip thru the strainer into the fermenter below leaving only hard & dry packed trub behind. This may take several hours or even overnight.
 

GrowleyMonster

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I don't wash the cake. The cake is already clean.

You let the kettle sit a couple hours to settle & clear. Place a 5 gal bucket strainer insert (micron rating of your choice) on top of your fermenter bucket. Open the kettle spigot and let the clear wort run thru the strainer into the fermenter. About 4 gals is above the spigot. There will be about 1 gal of wort/trub left in the kettle below the spigot. Dump the remaining kettle bottom into the strainer, sludge, hops and all. Only clear wort will drip thru the strainer into the fermenter below leaving only hard & dry packed trub behind. This may take several hours or even overnight.
What is your source for your 200u bucket strainer? Do you DIY this? Or is this paint equipment?
 

odie

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you can find them on ebay and amazon. Or other industrial suppliers.

search 5 gal bucket strainer or bucket filter or something like that. they are about 4-5 inches deep and have a fine mesh bottom. available in numerous micron ratings.

Mine are old ones I bought when I was making homemade "biodiesel" from used cooking oil. I think they were 200 but not 100% sure.
IMG_9639.JPG
IMG_9638.JPG
 

DBhomebrew

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Hmmm. Chill in the sink water bath like usual. That's pretty quick to ~100°. Transfer to my bottling bucket through the strainer as you show. Let it sit and drain for awhile as it continues to cool by itself. Cook, eat, clean up, put the kids to bed. Then transfer the filtered, cooled wort to the carboy. I like it.

For me that would be +~8% brewhouse efficiency.
 

DBhomebrew

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I am loving this paint strainer.

I used to leave up to a 1/2gal or so of wort in the trub/hop matter, pouring it down the drain through the disposal. Now, I dump the drained hops in the trash and they're no wetter than wasabi paste.

Depending on the beer, I'm getting a 6-15% increase in fermenter volume. From 3.5-3.75gal to a little over 4gal out of a 5gal kettle.
 
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