Stir plate in the ferm freezer?

[QJoshH]

Hey all - I just got a magnetic stir plate, but counter space and consistent temperatures are nonexistent in my house, so I'm trying keeping it in my ferm freezer. My concern is this: as I understand it, the whole principle behind the stir plate is that the vortex is constantly turning over the surface and exposing it to oxygen in the air... is that correct? If so, then being in the ferm freezer would mean that the supply of oxygen is limited at best, and at worst - when I have a carboy in there fermenting - the environment is actually full of CO2 coming off the fermenting beer. Mightn't this create a problem?
Thoughts? Solutions?

 

[petrolSpice]

How big is the fermentation freezer? I suspect there is plenty of oxygen in there to help a starter.

I wouldn't worry too much about temperature with a starter, off flavors are nothing to worry about. I try to keep mine in the low-mid 70's.

 

[QJoshH]

Small chest freezer - room for one 5 gallon carboy, but not two.
Temps in my house regularly range from 60-85F over the course of an average summer day. I'm not terribly worried about this for the starter, but there is literally NO place for me to put it! Let me rephrase... there is NO place to put it where it won't be in the way and my wife won't complain about the noise and smell of the stir plate (you know, the rattling of the stir bar and that smell of oil that comes from the motor...)

 

[Hermit]

Just opening the lid will stir the air in the chest. Just open it occasionally if you feel you need to.

 

[khawk95]

I ferment my starters in my chest fermenter all the time. No issues. I do it so they stay above 70 degrees. Warm is good for propagation.


Roed Haus Brewery

 

[trentm]

I have the same concerns. I feel consistent temp is important for starters and good aeration is imperative. When actively fermenting beer in my chest freezer fermenter there is absolutely no oxygen. A flame held inside the freezer will immediately extinguish. Without another fermentation in progress I feel your starter will have enough oxygen inside your chest.

Sure, you can culture a starter without oxygen but your final cell count may be severely reduced. See the chart on page four of this document: http://www.pivarstvo.info/forum/files/yeast_propagation_and_maintenance_128.pdf

I believe a temperature/oxygen controlled environment for your starter is very important in order to have consistent cell counts (from one starter to the next) and to enable the highest yield. As home brewers we often have to make due with what we have. My suggestion would be to find a location for your starter that will provide the most consistent environment possible and use that location each time you make a starter. That way, if you feel you are under/over-pitching you can adjust the size of your starter. That said, ideally that environment would be near 70degrees F and have plenty of fresh air.