Overpitching a Lager?

I'm making an Oktoberfest using Wyeast Bavarian Lager this weekend.

I stepped a up the yeast from a frozen vial I had to 3500ml on my stirplate. Mr. Malty gave me a 4.16 liter requirement but I seem to think his numbers are off.

Anyways, the starter has now crash cooled and I usually use these two resources to estimate my number of yeast cells.

MB Raines, Ph.D. - Guide to Yeast Culturing for Homebrewers - Maltose Falcons Home Brewing Society (Los Angeles Homebrewing)

Wyeast Laboratories : Commercial : Breweries : Technical Information : Yeast Harvesting

That being said, I have estimated I can get about 180 million cells per ml in a starter, thus 630 billion yeast cells this time around and Mr. Malty says I would need 422 billion cells.

So my question is this; Would this be overpitching? and Would this matter in a lager because it is supposed to have a clean fermentation anyways?

dfohio said:

Would this matter in a lager because it is supposed to have a clean fermentation anyways?

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That's my philosophy. When I get into summer lager mode, I just keep pitching on the prior batches cake. Each consecutive batch tastes better and better IMO.

I don't see how, in a lager and within reason, you could over-pitch. The less yeast growth you have, the less oxygen is required (so you might reduce your aeration a bit) and the less risk there is of producing esters, ketones (diacetyl), and sulfur compounds.

Thanks guys, I was leaning that way too. Just needed some confirmation.

jkarp,
There have been claims that under-pitching creates more esters but also claims that over-pitching creates more esters. Some have also said that perhaps a graph of ester production vs. pitch rate could have an upside down 'u' shape with maximums at the low pitch-rate end and high pitch-rate end.

Have you noticed any correlation between esters and cake 'generation' (i.e. first generation cake vs. second generation cake vs. 5th generation cake...)?

Do you aerate any differently (less?) when you pitch on big honkin' cake?
Do you experience very short lag times when you pitch on big honkin' cake?

I've only gone two cake 'generations' and was just curious.

dfohio said:

I stepped a up the yeast from a frozen vial I had to 3500ml on my stirplate. Mr. Malty gave me a 4.16 liter requirement but I seem to think his numbers are off.

Click to expand...

Did you select "stir plate" from the little drop down? That does seem like a very big starter.

SpanishCastleAle said:

jkarp,
There have been claims that under-pitching creates more esters but also claims that over-pitching creates more esters. Some have also said that perhaps a graph of ester production vs. pitch rate could have an upside down 'u' shape with maximums at the low pitch-rate end and high pitch-rate end.

Have you noticed any correlation between esters and cake 'generation' (i.e. first generation cake vs. second generation cake vs. 5th generation cake...)?

Do you aerate any differently (less?) when you pitch on big honkin' cake?
Do you experience very short lag times when you pitch on big honkin' cake?

I've only gone two cake 'generations' and was just curious.

Click to expand...

I've also heard the over-pitch ester claim, but in my experience I've seen no esters from over-pitching my lagers (or ales for that matter). Granted, the most I've done is 4 consecutive generations, and after the 2nd I start dumping off excess cake so perhaps I haven't hit the "upper" limit?

I stole this idea from BierMuncher for aeration and now use it for all my beers.

Lag times on 2nd gen and up are of course very short. Just last weekend I pitched a basic Pils wort onto a 2nd gen WLP830 cake at 48 deg and had airlock activity w/in the hour.

Beerrific said:

Did you select "stir plate" from the little drop down? That does seem like a very big starter.

Click to expand...

Yes I did.

Selections -
Lager
O.G. 1.055
US Gallons - 5.5
Liquid Yeast
Stir Plate

Output

Yeast Cells - 422 Billion - 1 vial - 4.16 liter starter


I don't think his cell count is off, but the factor of how many cells/ml in starter wort might be. It seems he uses 100 million/ ml where as I am estimating 180 million/ ml