Re-using last used yeast... by just throwing fresh wort onto yeast cake?

Title says it all really. I'm about to rack a RyePA and wanted to brew beforehand to just add the new wort to the same unwashed fermenter. I understand to watch temps....

Theoretically this would work right? Does anyone have experience doing this?

FWIW, the yeast is GigaYeast VermontIPA and I'm going to brew a pale ale, so the flavors won't be too far off.

You run a little risk with the unwashed fermenter. I have pitched on a yeast cake with good success but I transferred the yeast to a clean fermenter.

helibrewer said:

You run a little risk with the unwashed fermenter. I have pitched on a yeast cake with good success but I transferred the yeast to a clean fermenter.

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Naaahhhhhhh if the beer that comes out is good than the wort going in will be just fine! ROCK-n-ROLL for a time....

Cheers
Jay

Just make sure you have a big blow-off tube.

I think everyone does this at some point. I've had good success, people will tell you that you are way over pitching, and you are, but your beer should turn out fine.
Next batch has even more trub though.
I prefer to use a cupful of slurry and a clean fermenter but have found I don't have the desire to bottle and then brew on the same day.



Sent from my iPhone using Home Brew

Some food for thought:
https://www.homebrewtalk.com/f163/why-not-pitch-your-yeast-cake-166221/

What I do is just as easy as pitching on the yeast cake. I finish a batch of beer, and pour off about 2/3 of the yeast cake into sanitized mason jars and put them in the fridge. Then I use about a 1/2 cup of yeast slurry for the next batch, and have two more jars of yeast for my next batches. ( I make 10 gallon sized batches, so use twice as much yeast as a 5 gallon batch).

That way, I get about 10 batches of beer out of one package of yeast, without pitching on my yeast cake and without any problems at all.

It's not the best practice, but I've done with good results.

what about if i pitch a DIPA w/ OG 1.085 on top of a cake from a pale with OG of 1.055?

Yooper said:

Some food for thought:

https://www.homebrewtalk.com/f163/why-not-pitch-your-yeast-cake-166221/



What I do is just as easy as pitching on the yeast cake. I finish a batch of beer, and pour off about 2/3 of the yeast cake into sanitized mason jars and put them in the fridge. Then I use about a 1/2 cup of yeast slurry for the next batch, and have two more jars of yeast for my next batches. ( I make 10 gallon sized batches, so use twice as much yeast as a 5 gallon batch).



That way, I get about 10 batches of beer out of one package of yeast, without pitching on my yeast cake and without any problems at all.

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How long between batches? Or how long will that sit in the fridge before you use it?

Yooper said:

Some food for thought:
https://www.homebrewtalk.com/f163/why-not-pitch-your-yeast-cake-166221/

What I do is just as easy as pitching on the yeast cake. I finish a batch of beer, and pour off about 2/3 of the yeast cake into sanitized mason jars and put them in the fridge. Then I use about a 1/2 cup of yeast slurry for the next batch, and have two more jars of yeast for my next batches. ( I make 10 gallon sized batches, so use twice as much yeast as a 5 gallon batch).

That way, I get about 10 batches of beer out of one package of yeast, without pitching on my yeast cake and without any problems at all.

Click to expand...

Would you recommend to make a yeast starter from this slurry?

ericbw said:

How long between batches? Or how long will that sit in the fridge before you use it?

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msa8967 said:

Would you recommend to make a yeast starter from this slurry?

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Sometimes it's a long time between batches using the same yeast strain, sometimes not. I have about 6 strains of yeast right now in my fridge.

If it's been a while, more than a month, then I often will make a small starter or increase the pitching rate (using mrmalty.com's yeast slurry pitching calculator).

In all these years, I"ve had one batch that came out poorly that I attributed to a contaminated wort starter. So if I open a jar of yeast, and it doesn't seem exactly right (color, smell, etc), I toss it and don't use it. But I've held them in the fridge for months and months otherwise.

moreb33rplz said:

what about if i pitch a DIPA w/ OG 1.085 on top of a cake from a pale with OG of 1.055?

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You can do that, breweries cross pitch between styles all the time.

Yooper said:

Sometimes it's a long time between batches using the same yeast strain, sometimes not. I have about 6 strains of yeast right now in my fridge.



If it's been a while, more than a month, then I often will make a small starter or increase the pitching rate (using mrmalty.com's yeast slurry pitching calculator).



In all these years, I"ve had one batch that came out poorly that I attributed to a contaminated wort starter. So if I open a jar of yeast, and it doesn't seem exactly right (color, smell, etc), I toss it and don't use it. But I've held them in the fridge for months and months otherwise.

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That's what I thought. A starter seems like a good idea but not always necessary. I've used a scoop of just the sludge from a jar of saved yeast. Not really slurry because there's less liquid.

msa8967 said:

Would you recommend to make a yeast starter from this slurry?

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That would depend on how long the yeast sat in the refrigerator before your pitching it into your next batch. I figure 10% of the cells will die off after each month of storage and after a month or two, IMHO, a starter would be recommended.

I've only poured a new batch of Stout on top of some WLP-004 ale yeast that just finished one time before and the mess that followed was pretty bad so be prepared. I don't remember the Stout tasting bad at all but to me the loss of beer and the mess weren't worth repeating.

Why was there a mess?

moreb33rplz said:

Why was there a mess?

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A huge overpitch means an eruptive fermentation, and it tends to get really active and hot, really fast. Which means it will get even more active as it gets warmer, and then it will get explosive pretty quickly.

A "hot" fermentation will generally make a huge mess.

I love coming back to a started thread after a few days. Good read. I'm definitely going to do it then.

Yooper said:

A huge overpitch means an eruptive fermentation, and it tends to get really active and hot, really fast. Which means it will get even more active as it gets warmer, and then it will get explosive pretty quickly.

A "hot" fermentation will generally make a huge mess.

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Mostly from your comments, I've decided to poor off half to two thirds the trub into sanitized mason jars after racking the beer. The next time I make an IPA I'll use it and see what happens. :fro:

Thanks for all the input to everyone.

This fall I had 2 brews back to back with similar styles. First was a pumpkin ale, the second was a christmas spiced ale. Both same base beer with variance in to spice bill. After I bottled the first batch, I transfered the cake to a sanitized pickle jar and refrigerated it until the next morning brew day. When I finished up the brew day I was heavy on wort by nearly a gallon (produced more wort by gravity squeezing the bag than expected whoops) and realized that adding the whole cake would not leave sufficient head space. So, I scooped 3 cups of cooled wort into my flask, added a cup of slurrey and spun it overnight. In the morning I had a clean healthy krausen and pitched the whole thing, only adding a half cup volume to the original wort. My original plan had been to pitch the whole thing.

Yooper said:

A huge overpitch means an eruptive fermentation, and it tends to get really active and hot, really fast. Which means it will get even more active as it gets warmer, and then it will get explosive pretty quickly.

A "hot" fermentation will generally make a huge mess.

Click to expand...

Trust me... this is true.

Brewed last night. Dumped off half the trub, poured 2 gallons cold water in, siphoned the cooled wort in.... woke this morning and it was chugging along. Pretty vigorous, but not "explosive" or anything.

Now... there was a problem w/ the 1st batch. Attenuation was low. it was a RyePA (morebeer rye LME) that apparently finished @ 1.022, then I dumped half the beer out of the wine thief and it read 1.020. Fermentation was DONE. It tasted kind of wierd... somewhere in between like a sherry and an IPA, but I think that may be because I siphoned from the very top.... I read more today and I probably could have added Amylase to bring the FG down, but too late, I already kegged it. Depending how it tastes after carb'd I may remove from the kegerator, add some amylase, yeast, vent it and let it sit for a few days. We'll see.

I'm not sure if it was because of the yeast or because there were a lot of unfermentables. Whatever this 2nd batch's FG is, will confirm or deny that to a reasonable degree.

If you dump the new wort on top of the old yeast and fill the carboy pretty full, it's obviously going to blow out. Will it mostly be blowing off the old trub and dead yeast? (that would be good) Or is it mostly blowing off the good stuff?

I have no clue. It's not actually blowing out though. The krausen is essentially just filling the headspace.

In about an hour Im racking on some yeast I harvested from my fermenter earlier today. How much slurry is everyone using for their five gallon batches? Is 1/4 cup too much? Not enough? Im making a rye ipa and the og will hopefully be around 1.070

I"m going to go with a 1/4 cup of slurry for my 5 gallon batch. Hopefully it's not over pitched, but I do have a blow off hose just in case. We'll see how it goes

You want about a third of the yeast, whatever that works out to.

Haven't taken a hydrometer reading to be sure, but I think I under pitched. I ended up pitching 1/2 cup of slurry and the site I was looking at said that at 2 billion cells per ml I would need about 3/4 c slurry for a 1.062 beer. It doesn't look as clear as it should be either so we'll see how it goes. I'm going to let it set for another 12 days and then do the reading so hopefully it will get down to something decent by then