Homebrewers Association | AHA Forum

General Category => Yeast and Fermentation => Topic started by: dhacker on August 30, 2010, 05:49:57 PM

Title: Lager Starters at Lager Temps?
Post by: dhacker on August 30, 2010, 05:49:57 PM
Is that what you folks do?
Title: Re: Lager Starters at Lager Temps?
Post by: dak0415 on August 30, 2010, 05:53:33 PM
Nah, just pitch about 65, O2 and throw it on the stir plate!
Title: Re: Lager Starters at Lager Temps?
Post by: Hokerer on August 30, 2010, 05:54:51 PM
Is that what you folks do?

Haven't done lagers myself but, from reading from most others, nobody seems to worry about lager starters being at lager temps.  Since lager starters are so large, you'll be decanting off the spent "beer" and that's what higher temps would affect.
Title: Re: Lager Starters at Lager Temps?
Post by: gordonstrong on August 30, 2010, 05:56:25 PM
Not until I'm getting ready to pitch.  I normally put my yeast in whatever environment I'll use for fermentation the morning of my brew day.

I do all starters at room temperature, but I also pour off the spent starter wort and just pitch the yeast.  I like to make sure the starter is at the same temperature or slightly colder than the wort in the fermenter since a slight increase in temps will shock the yeast less than a slight decrease.

It's mostly a convenience thing for me; I don't want to set up a stir plate in my fridge.
Title: Re: Lager Starters at Lager Temps?
Post by: dhacker on August 30, 2010, 06:02:38 PM
Not until I'm getting ready to pitch.  I normally put my yeast in whatever environment I'll use for fermentation the morning of my brew day.

I do all starters at room temperature, but I also pour off the spent starter wort and just pitch the yeast.  I like to make sure the starter is at the same temperature or slightly colder than the wort in the fermenter since a slight increase in temps will shock the yeast less than a slight decrease.

It's mostly a convenience thing for me; I don't want to set up a stir plate in my fridge.

See . . that's the thing. I haven't done a lager since I've had my two stir plates and wasn't sure about rigging up something to use them in the ferment chamber . . I wanted to use the stir plates, but not in the ferment chamber. I've typically done my lager starters at the same temp I'd do my main ferment . . still decanting the liquid.

Always wondered if the lager yeast cell properties were different somehow after a warm ferment such as ambient room temp.
Title: Re: Lager Starters at Lager Temps?
Post by: bluesman on August 30, 2010, 06:06:13 PM
I ferment my lager starters between 60 and 70 depending on the ambient temp of my cellar at that particular time.
There's no need to ferment the starter at lager temps as I decant the beer and only pitch the slurry.

I also cold crash the starter the day prior to brewing to allow everything to drop out.  I will then warm it as Gordon has indicated to slightly below pitching temps.  This allows the yeast to come into a slightly warmer environment and waking them in preparation for the battle that lies ahead.
Title: Re: Lager Starters at Lager Temps?
Post by: gordonstrong on August 30, 2010, 06:07:27 PM
Make a double batch and try it both ways.  See if you can detect a difference.

It's not like the lager yeast are going to morph into ale yeast in one generation. Cool them down before you pitch and they'll get happy quickly in their new home.
Title: Re: Lager Starters at Lager Temps?
Post by: tschmidlin on August 30, 2010, 06:15:44 PM
Always wondered if the lager yeast cell properties were different somehow after a warm ferment such as ambient room temp.
Yes, the cell properties will be different in the ratios of the different fatty acids in the cell membrane.  The ratios vary with temperature to maintain the proper flexibility.

But I've never heard of it affecting the flavor of the beer, which is probably what you were asking about. :)
Title: Re: Lager Starters at Lager Temps?
Post by: dhacker on August 30, 2010, 06:34:39 PM
But I've never heard of it affecting the flavor of the beer, which is probably what you were asking about. :)


Mind reader!  :D
Title: Re: Lager Starters at Lager Temps?
Post by: dak0415 on August 30, 2010, 07:43:16 PM
Tom is to yeast as Kai is to mash chemistry :D
Title: Re: Lager Starters at Lager Temps?
Post by: chezteth on August 31, 2010, 02:09:36 AM
Not until I'm getting ready to pitch.  I normally put my yeast in whatever environment I'll use for fermentation the morning of my brew day.

I do all starters at room temperature, but I also pour off the spent starter wort and just pitch the yeast.  I like to make sure the starter is at the same temperature or slightly colder than the wort in the fermenter since a slight increase in temps will shock the yeast less than a slight decrease.

It's mostly a convenience thing for me; I don't want to set up a stir plate in my fridge.

+1 to this method.  I like to do this as well.

Brandon
Title: Re: Lager Starters at Lager Temps?
Post by: hiroller173 on August 31, 2010, 06:31:12 PM
I try to do everything at fermentation temp.  Only problem is that I need to prepare a few days earlier so that the starter is ready by brewday.  I use my stirplate in my fermentation fridge with no problems.  I chill the starter down to refrigerator temperature and decant most of the liquid.

Does it matter?  No idea, but my lagers come out really clean.
Title: Re: Lager Starters at Lager Temps?
Post by: majorvices on August 31, 2010, 11:21:13 PM
Greg Noonan once told me to ferment my lager starters at fermentation temp. But, I have to admit, I have tried it both ways and don't seem to notice a difference. You are growing yeast, not making beer. Like Gordon said - it ain't gonna morph into ale yeast in one gen. Theoretically you are selecting the warmer fermenting yeast. But, OTOH, its not like the colder fermenting strains are sitting there doing nothing the whole time.
Title: Re: Lager Starters at Lager Temps?
Post by: bluesman on September 01, 2010, 01:10:44 AM
That brings up a good point.  How many generations will it take to transform a lager yeast into thinking it's an ale yeast?
Not that yeast has a memory per say but over the generations will it climatize itself to growing in an ale temp environment and react negatively in a lager temp environment? 

Inquiring minds want to know?  :-\
Title: Re: Lager Starters at Lager Temps?
Post by: majorvices on September 01, 2010, 01:54:11 AM
Lots ;)
Title: Re: Lager Starters at Lager Temps?
Post by: tschmidlin on September 01, 2010, 03:33:25 AM
Yeah, the short answer is lots.

The long answer is it depends.  There is an element of randomness in where mutations occur, and I imagine it will take several accumulated mutations in the right spots to make the yeast incapable of fermenting at cool temperatures any more.  That's my best guess anyway, the S. cerevisiae (ale) genome is well studied, the S. pastorianus (lager) genome less so.  Any cell that picked up the mutations to prevent it from fermenting cold will only pass those on to its daughter cells, so over a few generations you'll end up with a handful of cells with those mutations, out of billions of cells that are just fine.

Although there are genes in S. cerevisiae that help it ferment at lower temperatures, I'm guessing that the ability to ferment at lower temps is something that came from the S. bayanus (wine) side of the family (lager yeasts are the result of a hybridization between ale and wine yeasts) but it's not clear to me how many genes are relevant.  Or it's possible there is some novel mutation or gene duplication event that allows for the lower fermentation event, or even some kind of synergistic effect from the combined gene products of the two strains.  It's possible this stuff is known, but I'm not up on the literature.  If I had research money to study it, I totally would.  Anyone got some spare cash lying around? :)

Anyway, all lager yeasts should grow well at warm temps, you're not in danger of selecting for warm fermenting but not cold fermenting cells unless they pick up some mutation that lets them ferment warm better than the lager yeast does.  It's just that you're no longer selecting for only cold fermenting cells, so you could hypothetically end up with some small percentage that will not ferment cold anymore.  Those will go dormant as soon as you pitch into your lager wort anyway, so it's no problem.

I'm going to guess that Wyeast and White Labs both grow their lager strains at warm temps for cell mass.  Growing at lower temps would take a longer time to get the same cell count and they'd probably have to charge more for lager strains due to tying up the incubators for longer periods of time.