Using Old Yeast Cake....

[thomasfgeary]

What are the benefits of keeping the old yeast cake in the carboy and pitching a new batch of wort on top of it??

 

[Revvy]

There's several threads on here that will answer your question...

Here's a couple I found using our handy dandy search button. (hint, hint)

https://www.homebrewtalk.com/showthread.php?t=60934

https://www.homebrewtalk.com/showthread.php?t=55223&highlight=yeastcake

https://www.homebrewtalk.com/showthread.php?p=607018

 

[thomasfgeary]

I skimmed through them, but none of them answered my basic question. I was wondering if there were any real advantages other then having to buy more yeast?

 

[mrk305]

It will take off like a rocket. Airlock activity starts in around an hour, and be sure to use a blowoff tube. It is kind of like using a starter on steroids. I usually pitch dry Nottingham yeast and a coffee cup full of trub instead of pitching over the whole yeast cake when I do it, mainly due to space in the bucket. I like to make 6 gallon batches in a 7.5 gallon bucket.

 

[Revvy]

It's a cheap way to re-use good yeast...
Explosive fermentation is fun!
You have to clean your fermenter less...


You can also get some nice flavors from the previous batch...in a dark beer you can get a level of complexity.

+1 on the blowoff tube...

 

[Dr_Deathweed]

If you are using liquid yeast you dont have to worry about a new starter or shelling out $7 for another batch of yeast.

 

[thomasfgeary]

it just seems like a very easy way to contaminate the beer.....I'll sterilize and pony up for the new yeast. Thanks for the info

 

[Dr_Deathweed]

well if your batch before was clean, and you cleanly racked, there is almost no risk of contamination. Plus there is this thing called "competitive inhibition." In case you do accidently contaminate just a little, seventy bazillion yeast cells vs. a couple hundred bacteria... Who do you think is going to win in a fight for the sugars in your beer

 

[Revvy]

well if your batch before was clean, and you cleanly racked, there is almost no risk of contamination. Plus there is this thing called "competitive inhibition." In case you do accidently contaminate just a little, seventy bazillion yeast cells vs. a couple hundred bacteria... Who do you think is going to win in a fight for the sugars in your beer

Plus if the cake has been sitting coverred in alchohol and you rack onto it the yeast is still protected.

But, I guess all of us (including papazian) who have been doing it for years must be wrong then.....Just like racking to secondary or opening the fermenter to take hydro readings....

 

[Yooper]

it just seems like a very easy way to contaminate the beer.....I'll sterilize and pony up for the new yeast. Thanks for the info

Well, I've done it a number of times. It is particularly good for "bigger" beers. When you buy a vial of yeast, there really aren't enough yeast cells to pitch into 5 gallons of wort, so you should make a starter to grow some yeast. You can then pitch that into your beer. However, if your gravity is, say, 1.070 or so, that still isn't enough yeast as a rule. Pitching on a yeast cake ensure enough yeast cells to ferment the wort that you have.

I try to go lower OG to higher OG (for the reasons I mentioned) and I also try to go lighter beer to darker (for the color). If I'm using a different type of beer, I wash my yeast. (See https://www.homebrewtalk.com/showthread.php?t=41768)
At $7 a vial for good yeast, I save whatever I can. I probably have about 20 jars of used yeast in my fridge.

The other thing to keep in mind- sanitation is crucial. If your primary is properly sanitized, there is no more risk of contamination than if you made a starter and pitched it.

 

[auto]

OK, got a newbie question. Have two beers coming out of fermentation, a Hefe and Alt (alaska Amber clone). The two beers on deck are a American Wheat, and a American Pale Ale. Would it be possible to use the yeast cake for either?

 

[Dr_Deathweed]

yeah, I would say pitch the wheat on the heff and the pale on the alt, but thats just me.

 

[Revvy]

OK, got a newbie question. Have two beers coming out of fermentation, a Hefe and Alt (alaska Amber clone). The two beers on deck are a American Wheat, and a American Pale Ale. Would it be possible to use the yeast cake for either?

You always want to go darker when you pitch on a yeast cake....So the flavor from the previous batch doesn't overpower the new batch.

 

[jdoyle83]

so you just racked a batch out of the primary and have another ready to go in on top of the yeast cake... what about the ring of krausen stuck to the inside of the bucket?
Do you let it ride, or use a (sanitized) spatula or whatever to remove it before adding the next batch?

 

[Revvy]

so you just racked a batch out of the primary and have another ready to go in on top of the yeast cake... what about the ring of krausen stuck to the inside of the bucket?
Do you let it ride, or use a (sanitized) spatula or whatever to remove it before adding the next batch?

I use paper towels dipped in sanitizer. I start below the krauzen ring and carefully wipe upward taking as much krauzen as I can in a single stroke...Then I go around the entire fermenter. I usulaly then go around 2 more times with sanitized paper towels until it's clean....

Also don't forget to use a blowoff tube when pitching onto a used yeast cake.

 

[thomasfgeary]

Thanks for all the advise. It seems like many people may be using a plastic bucket which is easier to clean. I am using a glass carboy and the amount of gunk in it after racking it to the secondary or bottles would be very hard to get out without risking contamination. I will try it on my next brew which is going to ba an imperial stout.

 

[Yooper]

I don't remove the krausen or do anything like that- I figured, it was sanitized when I closed it up, and I kept it closed up and was sanitary when I racked by using a completely sanitized siphon. I would wipe around the top before I put the new sanitized stopper and airlock in, though. Those stoppers don't really give me great confidence around the edges!

I've probably done this 20 times, and never yet had an infected batch.

If you're making an imperial stout, that would be an especially good use for a yeast cake.

 

[balto charlie]

Thanks for all the advise. It seems like many people may be using a plastic bucket which is easier to clean. I am using a glass carboy and the amount of gunk in it after racking it to the secondary or bottles would be very hard to get out without risking contamination. I will try it on my next brew which is going to ba an imperial stout.

I use glass as primary, sanitize the top outside edges, and pour a HUGE slug of it onto the new brew. I also pour another slug into a sterile mason jar and put into the fridge for a few weeks for the next beer. I usually get 3-4 batches per yeast package. I could get more but like to change to a different yeast and prefer(at this time) not to store yeast for prolong times. Eventually I will store yeast, grow hops and order only grains.....at least that's the plan. Charlie

 

[surfingpl]

OK, got a newbie question. Have two beers coming out of fermentation, a Hefe and Alt (alaska Amber clone). The two beers on deck are a American Wheat, and a American Pale Ale. Would it be possible to use the yeast cake for either?

I'm still learning so take this with a grain of salt.

Depending on what yeast you used for the Hefe, if you pitch wheat extract wort onto it, it's gonna be another hefe. The banana & clove flavors from a hefe yeast are going to be present in the next batch you pitch on that cake. Maybe change your next wheat beer to a weizenbock by adding 1/2lb of caramunich, and a 1/4lb of chocolate malt and up the ammount of extract you boil to get your starting gravity to about 1070.

I think the Pale Ale will work well on the Alt cake.

 

[jpsloan]

I have a question about the yeast, itself.

When the primary fermentation is over, and the yeast has had some time to start cleaning up the byproducts from the fermtation, does the yeast go into a new life cycle when it settles? When you pitch a new batch onto it, does the yeast switch back into growth mode to create new cells? I was just wondering if the shortened period between these two cycles doesn't produce cleaner beers.

 

[Dr_Deathweed]

Think of it more this way:

at first yeast have lots of oxygen and sugar, so they start aerobic metabolism and divide and multiply happily

When the oxygen wears out, they start trying to eat as much of the yummy sugars as they possibly can with anaerobic fermentation, because they are eating the sugars so fast, they have a "dirty metabolism" and let loose alot of by products into your beer (think peeing in the pool )

When they run out of sugar, they start to go into a kind of hibernation cycle by eating anything thats left (byproducts from previous) and storing it away. then they settle down (when your beer clears) and sleep until more O2 and sugars show up (pitch a new batch on top.

IMHO, a shorter cycle would produce dirtier beers because they will just eat the big sugars and not have a chance to clean up their mess behind them. A certain time after active fermentation to sit on the cake is not always a bad thing.

 

[jpsloan]

A certain time after active fermentation to sit on the cake is not always a bad thing.

Roger that! My last two brews, I let sit in the fermenter for three weeks before I bottled them. The flavors were much cleaner! :rockin:

 

[Dr_Deathweed]

Yeah, I don't know why many kits say to rack in the middle of or right after fermentation... I try to leave mine in the primary a week or two minimum after fermentation stops before racking. Let those yeasties eat thier poo:cross:

 

[mrk305]

I brewed a batch yesterday (Modified Edwort's Haus Pale with 13 pounds of grains @ 6 gallon batch) and scooped out about 5 ounces of trub in a sanitized coffee cup from a rye ipa and added that with a new hydrated pack of Nottingham yeast. This new beer is blowing like a leaf blower!! An aquarium pump does not put out this kind of volume. More than 5 bubbles @ second! Amazing! I probably did not need to add the new pack of Nottingham, but I don't do anything right anyway. I just kinda wing it and still end up with really good beer!