can i just put my new wort ontop of the old yeast cake?
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I've never had any problems doing it, in fact, I've had fantastic luck doing it. Get ready for some wild fermentation and have a blow off tube handy.
Yup perfectly fine and a fairly common practice. Get ready for crazy fermentation. Two things to look out for 1) you can only pitch ontop of the same cake 2-3 times and 2) people generally start with a lighter brew and pitch progressively darker ones on top of the cake, otherwise you pale ale may end up being less than pale
davesrose
Well-Known Member
Well the advantages: more then enough yeast cell count, pretty cheap
disadvantages: can impart flavors in your second beer that you weren't expecting, more chance for a contamination to occur.
So if you think the yeast cake is pretty clean and appropriate for your wort...by all means pour on top. Don't keep recycling that cake though (as I now notice has been mentioned only do 2-3 times): it will always be getting more floculants and having bigger room for more contaminates.
disadvantages: can impart flavors in your second beer that you weren't expecting, more chance for a contamination to occur.
So if you think the yeast cake is pretty clean and appropriate for your wort...by all means pour on top. Don't keep recycling that cake though (as I now notice has been mentioned only do 2-3 times): it will always be getting more floculants and having bigger room for more contaminates.
I have done it with no problems dumping a barley wine on a yeast cake, I have not really dumped a 1.050 beer on a yeast cake....
Some will say its not a good idea
Some will say no problem
As long as your sanitation is good it wont hurt anything, go for it and make your own opinion. Keep the temp down, your gonna get a rapid crazy fermentation, good luck!
Some will say its not a good idea
Some will say no problem
As long as your sanitation is good it wont hurt anything, go for it and make your own opinion. Keep the temp down, your gonna get a rapid crazy fermentation, good luck!
bmckee56
Well-Known Member
I have done so in making Wine, but never thought to do it with beer. I currently have an IPA in a primary and planned to start a Blonde Ale on Friday, but I may wait a few days for the IPA to be racked to secondary and re-use the yeast cake 
I can then save my White Labs Yeast for a later day.
What are your thoughts on using the yeast cake from the IPA to do the Blonde Ale? Both are Ale's.
Salute!
I can then save my White Labs Yeast for a later day.What are your thoughts on using the yeast cake from the IPA to do the Blonde Ale? Both are Ale's.
Salute!
Bob
Well-Known Member
Wait - aren't you the guy who was asking why you couldn't use just one cell in a different thread? 
I don't recommend it. It is always excessive over-pitching. Over-pitching results in - comparatively speaking - mediocre beer. Without intending offense to those who practice the procedure, I have no choice but to say it's also lazy. Here's my reasoning.
The vast majority of beer styles rely on a certain flavor characteristic imparted by the yeast. Over-pitching suppresses the development of those flavor precursors by removing the reproductive phase. That might be fine for a Light American Lager, but it's the death of all English and Belgian Ales, as well as most American styles and wheat beers.
The yeast in the slurry have just conducted a vigorous ferment (if you've performed good yeast management). They've just worked really, really hard. By knocking out fresh wort onto the cake, you're asking them to perform the same task - or a significantly harder task, depending on how high the new wort's gravity - without replenishing themselves. In essence, you're asking them to perform the same without permitting them to conduct a crucial portion of their life cycle.
You're knocking out into a filthy fermenter. I don't know how brewers are making the mistake of thinking that something that is visibly not clean is okay to receive wort. The same brewers who will tell you to not touch the inside of a plastic bucket fermenter for fear of scratching it are all too ready to tell you it's perfectly all right to put fresh wort into a receptacle that is covered in muck. Ew. The rule is simple: if it looks dirty, it is dirty. Clean it and sanitize it before the next use.
In other words, it's lazy; can't be bothered to compute and pitch the correct amount of yeast for style and gravity, can't be bothered to conduct yeast management, can't be bothered to even clean the gear? Then follow that procedure. How can consistently excellent beer come out of such an arrangement? Short answer: It can't. The procedure deliberately ignores too many things absolutely essential to world-class beer.
Can you make good beer by knocking out onto a yeast cake? Sure. Can you make consistently excellent beer? Nope.
That's my tuppence, anyhow. Again, I don't mean to give offense to anyone who's experienced acceptable results with that method.
Cheers!
Bob
I don't recommend it. It is always excessive over-pitching. Over-pitching results in - comparatively speaking - mediocre beer. Without intending offense to those who practice the procedure, I have no choice but to say it's also lazy. Here's my reasoning.
The vast majority of beer styles rely on a certain flavor characteristic imparted by the yeast. Over-pitching suppresses the development of those flavor precursors by removing the reproductive phase. That might be fine for a Light American Lager, but it's the death of all English and Belgian Ales, as well as most American styles and wheat beers.
The yeast in the slurry have just conducted a vigorous ferment (if you've performed good yeast management). They've just worked really, really hard. By knocking out fresh wort onto the cake, you're asking them to perform the same task - or a significantly harder task, depending on how high the new wort's gravity - without replenishing themselves. In essence, you're asking them to perform the same without permitting them to conduct a crucial portion of their life cycle.
You're knocking out into a filthy fermenter. I don't know how brewers are making the mistake of thinking that something that is visibly not clean is okay to receive wort. The same brewers who will tell you to not touch the inside of a plastic bucket fermenter for fear of scratching it are all too ready to tell you it's perfectly all right to put fresh wort into a receptacle that is covered in muck. Ew. The rule is simple: if it looks dirty, it is dirty. Clean it and sanitize it before the next use.
In other words, it's lazy; can't be bothered to compute and pitch the correct amount of yeast for style and gravity, can't be bothered to conduct yeast management, can't be bothered to even clean the gear? Then follow that procedure. How can consistently excellent beer come out of such an arrangement? Short answer: It can't. The procedure deliberately ignores too many things absolutely essential to world-class beer.
Can you make good beer by knocking out onto a yeast cake? Sure. Can you make consistently excellent beer? Nope.
That's my tuppence, anyhow. Again, I don't mean to give offense to anyone who's experienced acceptable results with that method.
Cheers!
Bob
cdburg
Well-Known Member
If it were me, pitching part of the cake would definitely be the way to go. You can read more about the argument for it here:
Proper Yeast Pitching Rates
You can use the Mr. Malty Pitching Rate Calculator to figure out how much of the yeast slurry you would need to pitch into the new batch.
Mr Malty Pitching Rate Calculator
Proper Yeast Pitching Rates
You can use the Mr. Malty Pitching Rate Calculator to figure out how much of the yeast slurry you would need to pitch into the new batch.
Mr Malty Pitching Rate Calculator
Mutilated1
Beer Drenched Executioner
split the yeast cake in half and make two beers, you'll have a huge amount of yeast
brown_dog_us
Well-Known Member
You can rack on top of a yeast cake and make good to great beer. Is it the optimal method? Nope, but it isn't going to have a huge impact on the quality of your beer. As home brewers we can do things that are not perfect, but produce acceptable results. Things like malt extract, steeping instead of mashing, etc. are not the perfect way to brew, but they work fine. If you are worried about the negative effects of over pitching, then remove about half of the slurry and you'll be close to the correct pitching rate.
maltMonkey
Well-Known Member
I used to pitch onto the entire cake until recently when Bob edumucated me
Honestly, most of the beers I did this with turned out pretty decent, save a Kolsch that has an autolysis problem (pretty nasty rubber taste). I am chalking this problem up to severely overpitching with a very light grain bill (nothing to mask any off flavors), and I won't do it again.
I always knew I was overpitching, but had read too many people say things like "It's almost impossible for a homebrewer to overpitch", so I didn't worry about it.....then I found out just how much I was overpitching by: on a recent batch I collected the yeast cake into a large mason jar, and after things settled in the fridge for a couple days, I ended up with 1000 mL of slurry. Using the mrmalty pitching calculator, I found that I only needed 80 mL of slurry for my next beer! Had I pitched onto the cake, I would have been pitching almost 13 times too much yeast!
I think you can get away with pitching onto the entire cake with a high gravity lager, but I'm sold on using the calculator and pitching the recommended amount now.
Honestly, most of the beers I did this with turned out pretty decent, save a Kolsch that has an autolysis problem (pretty nasty rubber taste). I am chalking this problem up to severely overpitching with a very light grain bill (nothing to mask any off flavors), and I won't do it again.
I always knew I was overpitching, but had read too many people say things like "It's almost impossible for a homebrewer to overpitch", so I didn't worry about it.....then I found out just how much I was overpitching by: on a recent batch I collected the yeast cake into a large mason jar, and after things settled in the fridge for a couple days, I ended up with 1000 mL of slurry. Using the mrmalty pitching calculator, I found that I only needed 80 mL of slurry for my next beer! Had I pitched onto the cake, I would have been pitching almost 13 times too much yeast!
I think you can get away with pitching onto the entire cake with a high gravity lager, but I'm sold on using the calculator and pitching the recommended amount now.
PavlovsCat
Well-Known Member
2 questions:
1. Do you just simply pour on top of it?
2. How long do you give it before pitching additional yeast?
1. Do you just simply pour on top of it?
2. How long do you give it before pitching additional yeast?
brown_dog_us
Well-Known Member
1. You can. Some people clean the Kraussen ring off the fermentor or dump the slurry into another containner while they clean/sanitize the fermentor.
2. You shouldn't have to add any more yeast. It'll take off very quickly.
grammatron
Well-Known Member
Wow, was this thread on the front page when I made my other thread earlier today? I gotta pay more attention.
gwalt
Well-Known Member
If saving a few dollars on yeast is the goal, then why not invest in a kit to culture yeast? I've seen them around and they are only $25-$35.
gwalt
Well-Known Member
2 mins of cleaning fermentor + $1.50 for new yeast = The flavor your looking for!If you just want cheap/free alcohol make apflewein.Nothing wrong with apflewein,Just saying it's easy/quick/cheap/drunk
Right now the drunk
portion sounds REALLY good!!! Cheers! 
Talloak
Well-Known Member
I think this would require yeast washing, a process of purifying the sample, and can also be performed on commercial beers (Sierra Nevada).
