Question pitching Imp. Stout onto yeast cake

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Jbear

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I love big stouts and have been wanting to brew one for awhile so I've decided to take the plunge this Sunday and brew up something in the 1.100ish range while I still have a good 6-8 months for conditioning before wintertime stout drinking weather rolls back around.

As a happy coincidence, I brewed a 5% brown porter about 3 weeks ago with London Ale yeast, which seems like a great choice for the stout so I have a nice yeast cake to work with. Almost every single ingredient in the porter is in the stout recipe so I have no concern of off flavors from the trub.

My question is more one of amount... Should I pitch the stout onto the entire cake? Or should I remove some, and if so, how much? I should clarify that the fermenter is an unmodified (other than taking the spear out) 1/4 barrel keg so I can't really reach in and scoop out yeast or anything but I could dig the siphon around in the cake to get some out while racking to the keg.

I looked at MrMalty, but I don't really know where to set the sliders on the slurry page. How would I know what my non-yeast percentage is for example? Nor do I have a way to measure the volume of slurry that's in the fermenter.

Thanks in advance for any help. Obviously this is a big beer that will have lots of materials and time involved so I want to make sure it has the best possible fermentation!

Cheers
 
Just pitch it and you'll be fine. There's other things that could be done like washing the yeast, but under no circumstances is it absolutely necessary so don't stress about it. Make sure to aerate your wort well and then pitch. Big beers need plenty of dissolved O2. And as far as MR Malty goes, go back into the history on your computer and delete the web page. That guy just makes everyone crazy.

While I'm on that, the last winter warmer I did, that ridiculous calculator said I'd need 8 packs of yeast to pitch. That's like $60 in yeast. This is with an overnight 1 quart starter and 2 Irish Ale yeast packs from wyeast.

DSC00718.jpg
 
Just pitch and go. I've done a couple of Imperial Stouts lately, one pitched on a yeast cake and the other with a starter. Both are fine but the yeast cake one really took off with no problems. Turned out really well, too. I wouldn't worry about over pitching or washing the yeast in this case. I think you're good to go.
 
Damn, that's quite the blow off!! I had one go a little crazy on me lately that I had made a nice big 2L starter for, but it pales in comparison to that, lol.

Thanks for the feedback guys I'll go for it on the porter yeast cake! I'm excited for this brew!
 
Double_D said:
as far as MR Malty goes, go back into the history on your computer and delete the web page. That guy just makes everyone crazy.

this seems like questionable advice. No doubt JZ is full of himself on the radio, but many of the most awarded home brewers, researchers, and pro brewers agree with his yeast pitching approach.

IMO/IME fermentation is the biggest factor in making quality beer, so it makes sense to measure your yeast amounts rather than just pitching a random amount and hoping for the best.
 
I wouldn't say a yeast cake is a random quantity any more than what I already stated as my starter. That calculator he has makes a lot of assumptions too. But look at this and tell me it's legit. A 1.5 gallon starter with 5 packs of yeast or 13 packs of yeast by them selves? The "Majority" can be wrong. Everyone used to think the earth was flat too. How many people still mash for an hour? I bet those guys do too. Awesome. It's to small to read. I put in my last batch OG 1.075/10.25 gal and that's where I got the numbers..

Screen shot 2012-04-20 at 8.15.52 AM.jpg
 
I tend to step up my starters rather than pitching a bunch of vials/smack packs. Not that rich. So I feel where you're coming from. That said, I don't think that much yeast is necessarily out of line.

I should also clarify that I'm not telling you what to do. You clearly have your own system going and it works for you; I respect that. I have no way to judge (nor inclination) the results you get and it'd be irrelevant if I did.

But what I wrote was that's it's "questionable advice" and I stick to that statement. Not everybody who comes here looking for advice has worked out a system like you seem to have done. For those people, a system like Mr. Malty is more user friendly that multiplying 1 billion yeast cells/gallon (or whatever) and adjusting for gravity. And I don't think anyone who makes good beer would say that pitching rates are irrelevant, so people need something to go by while they gain experience. That's my only real point.

Cheers to better beer!
--pirat
 
this seems like questionable advice. No doubt JZ is full of himself on the radio, but many of the most awarded home brewers, researchers, and pro brewers agree with his yeast pitching approach.

IMO/IME fermentation is the biggest factor in making quality beer, so it makes sense to measure your yeast amounts rather than just pitching a random amount and hoping for the best.

I think Mr. Malty is just wrong with respect to using slurry. It is pure guesswork to begin with, and the viability numbers (to me) seem completely over-estimated.

I don't have any issues with it's recommendation for new yeast. It's based on pretty well accepted number of yeast cells required, and the viability of new yeast seems reasonable.


For the OP: For almost any ale (not lager), the yeast in the cake will be roughly 6 times what is recommended for an initial pitch to a beer of that same starting gravity. I assume some loss, and figure a cake has 4X the yeast required for a beer of the same gravity. If the beer is twice the gravity (as it seems in your case), you would need twice the amount of yeast. So to pitch roughly the correct amount of yeast, you would need about half the cake. If there is any way of taking some out, I would recommend it. Using all the cake will probably work fine, but you will lose out on some of the yeast flavors, the precursors of which are created during the yeast reproduction phase; pitching too much yeast reduces the amount of new yeast formed, reducing some of the esters.
 
I wouldn't say a yeast cake is a random quantity any more than what I already stated as my starter. That calculator he has makes a lot of assumptions too. But look at this and tell me it's legit. A 1.5 gallon starter with 5 packs of yeast or 13 packs of yeast by them selves? The "Majority" can be wrong. Everyone used to think the earth was flat too. How many people still mash for an hour? I bet those guys do too. Awesome. It's to small to read. I put in my last batch OG 1.075/10.25 gal and that's where I got the numbers..

Wait, what's wrong with mashing for an hour?
 
this seems like questionable advice. No doubt JZ is full of himself on the radio, but many of the most awarded home brewers, researchers, and pro brewers agree with his yeast pitching approach.

I don't have anything bad to say about JZ! I'm by no means a "pro" at brewing, but I tend to prefer YeastCalc.com over MrMalty. I've gotten crazy pitching advice from MrMalty as mentioned above. Plus, I am a "step-up starter" kind of guy, and YeastCalc seems to be more geared towards that....
 
Wait, what's wrong with mashing for an hour?

It's not necessary with modern malt. With respect to domestic malt, I've used briess and northwest and had compete conversion in about 15 minutes. And this is the same philosophy at the local micro brewery(Big Dog's). I've also had conversion of weyerman wheat malt along the same timeline with briess and northwest 2-row(50/50 mash). I use them interchangeably depending on what's at the LHBS.
 
I think Mr. Malty is just wrong with respect to using slurry. It is pure guesswork to begin with, and the viability numbers (to me) seem completely over-estimated.

I don't have any issues with it's recommendation for new yeast. It's based on pretty well accepted number of yeast cells required, and the viability of new yeast seems reasonable.


For the OP: For almost any ale (not lager), the yeast in the cake will be roughly 6 times what is recommended for an initial pitch to a beer of that same starting gravity. I assume some loss, and figure a cake has 4X the yeast required for a beer of the same gravity. If the beer is twice the gravity (as it seems in your case), you would need twice the amount of yeast. So to pitch roughly the correct amount of yeast, you would need about half the cake. If there is any way of taking some out, I would recommend it. Using all the cake will probably work fine, but you will lose out on some of the yeast flavors, the precursors of which are created during the yeast reproduction phase; pitching too much yeast reduces the amount of new yeast formed, reducing some of the esters.

Thanks Calder, that is the information I was looking for regarding the yeast cake. I will siphon some of the cake out when I rack the beer off. I probably won't get exactly half but it will get me closer to the correct amount.

I tend to agree that MrMalty is pretty accurate from what I've seen on new yeast - I always set the slider to use the fewest number of packs, which usually gets you down to 1, and just prefer to make a larger starter. The slurry tab though does seem to assume a lot, unless you have a microscope to analyze your yeast cake.

I didn't know about yeastcalc.com, thanks for that recommendation. I'll give it a try.

Cheers!
 
Stauffbier said:
I don't have anything bad to say about JZ! I'm by no means a "pro" at brewing, but I tend to prefer YeastCalc.com over MrMalty. I've gotten crazy pitching advice from MrMalty as mentioned above. Plus, I am a "step-up starter" kind of guy, and YeastCalc seems to be more geared towards that....

Thanks for the tip, Stauffbier! I'll check out YeastCalc.com. I'm always open to new tools for better beer!
 
pabloj13 said:
Wait, what's wrong with mashing for an hour?

Nothing. Several sources have run tests, and conversion usually happens well before the 60 minute mark. In the BYO survey study, some brewers reported full conversion within 20 minutes while others took as many as 45.

Long story short, just like you should use a hydrometer instead of airlock activity to measure completed fermentation, you should use a starch-iodine test instead of an egg timer to measure conversion.

I don't, but I should! I just allow 45 minutes now instead of 60.
 
Nothing. Several sources have run tests, and conversion usually happens well before the 60 minute mark. In the BYO survey study, some brewers reported full conversion within 20 minutes while others took as many as 45.

Long story short, just like you should use a hydrometer instead of airlock activity to measure completed fermentation, you should use a starch-iodine test instead of an egg timer to measure conversion.

I don't, but I should! I just allow 45 minutes now instead of 60.

I checked for conversion on my last batch at the 20 minute mark for the first time, and It was already giving me a good iodine test. Since I saw that I've been planning on trying a 30 minute mash...
 
Nothing. Several sources have run tests, and conversion usually happens well before the 60 minute mark. In the BYO survey study, some brewers reported full conversion within 20 minutes while others took as many as 45.

Long story short, just like you should use a hydrometer instead of airlock activity to measure completed fermentation, you should use a starch-iodine test instead of an egg timer to measure conversion.

I don't, but I should! I just allow 45 minutes now instead of 60.

Interesting. Thanks, guys. Learn something new every day.
 
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