Yeast Cell Count

[Kane Brews]

Hi Guys - I poked around on the forums here and also homebrewtalk.com to see if I could find info on this, maybe I'm searching under the wrong search words? Here's the dealio.... we're going to make a Coffee Porter tomorrow. We've have an old-ish Wyeast smack pack of London Ale (Nov. 27th manf. date), I'm on the 2nd step of making a starter, the ending cell count should be 108 billion according to the Brewer's Friend calculator. This recipe (and wort gravity) calls for about 70 billion. One step was not enough, step 2 is too much? Here it comes watch for it ...semi rookie question...do we pitch it all? Can you over pitch? I realize this is not an extreme number 108 vs 70 , but also for future knowledge what would happen if you tossed in 300 billion cells when you only needed 100? Not so sure this would ever happen but you never know!! Trying to learn. Thanks in advance guys for your sage advise.

 

[Hawkbox]

At a homebrewer level it's nearly impossible to overpitch. Just toss it in.

 

[GFHomebrew]

yep its gunna be a big beer anyhow so above or around propper pitch rate = cleaner beer and excellent fermentarion/attenuation. im more of a hobbit than a sage lol

 

[Mark Farrall]

Small batch brewer, so I'm constantly fighting with overpitching. Generally overpitching means less budding and a low stress initial phase of fermentation. That will mean less esters and phenols. So for some beers, that's great, others, not so much.

 

[Kane Brews]

That’s interesting. Don’t make a lot of big beers, 6% is pushing outside of our envelope. In the past we have only used liquid yeast when we’re making 5 gallons. I know some of you are going to say we’re crazy but we have zeroed in on about 3 gallon net extract brews with grains and it works for us. We’re brewing more often and it’s coming out better. Why? Don’t ask me. Lol. Mark to your point, we’ve been using a whole pack of dry yeast mostly, I’ve never really contemplated this before, but that might be too much for certain beers? Hummmm Which styles could it effect negatively? And you’re right we don’t get a ton of air lock activity. I thought it was the headspace so we picked up a couple of 5 gallon pails for fermentation and a 3 gallon car boy. Same result. But getting a good krausens and hitting our final gravitys pretty consistently so must be the low stress in the initial phase. I find brewing kind of like playing golf, too much to think about, dont get too serious....just go out and have fun right?

 

[Hogarthe]

Without a microscope and hemacytometer you really don't know if you are overpitching. The calculation can't take every possible variable into account so its just a guess. I'd pitch the whole starter. Even if you have a bit extra its better to have too much instead of too little.
As for your hypothetical 300 billion when you need 100, that could be a problem. At a huge overpitch you won't get any fermentation character and can end up with a beer that tastes a bit lifeless. Especially if you are using a strain that is supposed to give you a lot of esters or phenol flavors, the yeast won't enter the stage where they produce them.

 

[Nosybear]

Small batch brewer, so I'm constantly fighting with overpitching. Generally overpitching means less budding and a low stress initial phase of fermentation. That will mean less esters and phenols. So for some beers, that's great, others, not so much.

Yep. In fact the best way to get a good Hefeweizen is to under-pitch. And you can estimate fairly well - yeast's propagation rate is pretty well known, the rate at which it dies off over time is pretty well known so calculators actually do a fair job, close enough for homebrew, anyway.

 

[Mark Farrall]

Styles where most people are looking for some yeast flavours (the phenols and esters) are German wheats, most Belgians and to a lesser extent most UK beers.

That said, even in those styles you may prefer the more neutral versions, so it's according to taste.

Add I'm a 5 litre (1 gallon) brewer, so your 3 gallon doesn't seem small to me.