Over sized fermenter

[Jtvann]

I'm confused. Oxygen is good for yeast in initial phases ... which is why we Oxygenate. Am I missing the point of purging headspace with CO2 after purposefully adding O2?

 

[NSMikeD]

I'm confused. Oxygen is good for yeast in initial phases ... which is why we Oxygenate. Am I missing the point of purging headspace with CO2 after purposefully adding O2?

IMO, no. The yeast needs O2. IMO, the yeast will purge with CO2 for you, so long as you see the airlock bubble during the initial stage. I do get why you would use O2 instead of air that may contain unwanted bad guys, but my understanding the with active initial fermentation, it's not an issue, the yeast will outcompete the bad guys in that air.

The OP asked about an oversized fermentor. In theory the additional airspace could be an issue if the initial fermentation doesn't purge the air. IMO, making. fermentation bucket is easy and cheap, so I think it shouldn't preclude anyone from adding a smaller fermentor if one expects to brew small batches.

 

[Jtvann]

IMO, no. The yeast needs O2. IMO, the yeast will purge with CO2 for you, so long as you see the airlock bubble during the initial stage. I do get why you would use O2 instead of air that may contain unwanted bad guys, but my understanding the with active initial fermentation, it's not an issue, the yeast will outcompete the bad guys in that air.

The OP asked about an oversized fermentor. In theory the additional airspace could be an issue if the initial fermentation doesn't purge the air. IMO, making. fermentation bucket is easy and cheap, so I think it shouldn't preclude anyone from adding a smaller fermentor if one expects to brew small batches.

Yeah, kinda figured the same. I mean I wouldn't ferment a 5 gallon batch in a barrel fermenter, but anything within reason ought to be fine.

 

[Nate R]

I'm confused. Oxygen is good for yeast in initial phases ... which is why we Oxygenate. Am I missing the point of purging headspace with CO2 after purposefully adding O2?

For me, having a sealed and easy to use fermentor (spike cf5) it only adds an extra 30 seconds or so to purge.
Agree it probably is not needed (how many thousands of years has beer been made in open vats, still today?!).
But, i follow a "minmize any risk i can rule". Aka, if i can easily purge the head space with c02, for a penny or two and 20 seconds of my time, that is an easy step to help reduce a potential, albeit miniscule, infection point.
To each his or her own. That's the great thing about this hobby!

 

[wsmith1625]

I've heard of guys pushing 5 gallons of sanitizer through 2 corny kegs with fermenter co2. That's a lot of co2 from a 5 gallon batch. Makes me feel like you'll be fairly safe doing a smaller batch in a large fermenter. Just my 2 cents.

 

[Jtvann]

For me, having a sealed and easy to use fermentor (spike cf5) it only adds an extra 30 seconds or so to purge.
Agree it probably is not needed (how many thousands of years has beer been made in open vats, still today?!).
But, i follow a "minmize any risk i can rule". Aka, if i can easily purge the head space with c02, for a penny or two and 20 seconds of my time, that is an easy step to help reduce a potential, albeit miniscule, infection point.
To each his or her own. That's the great thing about this hobby!

I dont mind you purging headspace. You do you bud.

I was just asking about "minimize any risk I can" ... what is being minimized? I cant figure out what the point of doing it is, even on a minuscule stage.

 

[Gregory T]

remember the days of vigorously shaking and stirring the wort to aerate it prior to pitching. I aerate by using a venturi in the hose from the kettle to the fermentor

 

[Merleti]

I've made many a venturi but never ended up trying one to aerate wort. I used to use an air pump with a inline filter.

 

[Gregory T]

I've made many a venturi but never ended up trying one to aerate wort. I used to use an air pump with a inline filter.

Here it is

 

[VikeMan]

Aka, if i can easily purge the head space with c02, for a penny or two and 20 seconds of my time, that is an easy step to help reduce a potential, albeit miniscule, infection point.

When you knock all (actually most) of the O2 out of the head space by purging, some of the dissolved O2 will replace it, as it seeks equilibrium between the wort and the headspace.