How Long to Oxygenate wort?

[Rocker1986]

Well I pitch the whole starter worth of yeast, yeah, however I crash and decant my starters so I'm not pitching 2 or 3 litres of unhopped beer as well.

I work out how big a starter I need for a given batch, then make it a litre bigger to harvest some into a quart size mason jar for the next time. It's been working well for me so far.

 

[micblair]

10 mins of O2 at 2 L/min directly injected into the wort stream over a 45 minute transfer to the FV would result in 8-12 ppm of O2 (measured with a HQ40D). Other breweries I've worked at go for 0.5L - 1 L/min for the whole transfer. At home I don't have a flowmeter or DO meter, but I use a 2 micron stone with O2 for 3-5 minutes post pitching to help mix the yeast through.

 

[professional_drunk]

I've been oxygenating my wort for a while now. Recently I did a 1.046 wort with wyeast ringwood ale and I had accidentally run out of o2 so it didn't get my usual treatment and I didn't do any manual methods for introducing o2. This beer turned out fantastic btw. I'm starting to suspect that the importance of o2 may either be

• yeast strain dependant
• not required for yeast that's been exposed to o2 on a stir plate
• only relevant for repitching

As for dry yeast, I did once try oxygenating a 1.055 wort that I was using notto in and the beer turned out horribly oxidized. It's as if the yeast had it's fill of o2 and left it in the wort.

I've got another wort of 1.048 ready to pitch with stir plated yeast. I'm going to try pitching it without o2 and see if I get the same results.

I've just completed 2 beers which I purposely didn't use o2. Same process of stepping up on a stir plate and no aeration methods used at all except for what may occur when pouring into the fermenter.

1. wyeast ringwood ale OG 1.036.
Clean tasting, no signs of any off flavours, attenuated normally. Though lower in OG, it's good to see a repeat of the results I got last time.

2. wyeast american ale II OG. 1.048
Attenuated normally, definite off flavours. This tastes like the beers I used to make in my early brewing days. Considering whether this should go down the sink.

So as for the question of how long to o2 wort, I think if it's stir plated and used for 1 generation then the answer is strain dependant. Though take that with a grain of salt as this experimentation was hardly scientific.

 

[Danscraftbeer]

All relevant though. We are not scientists.

The instructions of Nottingham yeast for eg. says to hydrate with water only and aeration of wort is unnecessary.
Silly me am skeptical of that. But they are the scientists.
Its a result of my first learnings that a boiled wort is depleted of oxygen. :unsure:
After reading all this I'm more inclined not to consider trying the bottled O2 method. Far too many variables that I cant measure.
There may be more risk of over oxygenation which I didn't think possible but when it comes to Beer it is.

 

[thylacine]

An experiment from the site "BRULOSOPHY"



WORT AERATION – PT. 1: SHAKEN VS. NOTHING | EXBEERIMENT RESULTS!


"...My Impressions: Blinded or not, I could not reliably tell a difference between these beers. I fully agree with the remarks of panelists regarding how difficult it was to tell a difference. Both beers were great, I happily drank from both the non-aerated and aerated kegs… perhaps a bit more often than I should have..."

http://brulosophy.com/2015/05/25/wort-aeration-pt-1-shaken-vs-nothing-exbeeriment-results/

 

[TheWiggman]

This is all getting off-track and sounding a little anti-science.
Wyeast have their recommendations and I'm sure if other yeast manufacturers were asked they would support Wyeast's recommendations and theory behind it.
Big breweries use O2 and if it didn't make a difference I have no idea why they'd waste their money with it.
Various yeast boffins have been quoted on this forum recommending O2 concentrations consistent with yeast manufacturers.
Why disagree? Home brewing is chockas with unknowns and ways to go wrong. Doing a little bit in lots of areas will improve the beer, each little element may not make an apparent difference in isolation but together it's the difference between good and bad beer.
Not sure why I'm defending it, maybe all the pros are wrong?

 

[Dunkelbrau]

Commercials aren't wrong.

They use a sinter stone during transfer usually as stated above (1L/m) ive seen some people do 1.5L/m as well and the fv is open to release pressure.

The problem is the temp at transfer. If its still 26 degrees then you won't get as much dissolved as if it was 8 degrees.

 

[micblair]

Big breweries use O2 and if it didn't make a difference I have no idea why they'd waste their money with it.

Tooheys when brewing Kirin Ichiban under license at the Malt Shovel use compressed air. Apparently the Japanese prefer this over oxygen (perhaps there's less risk of over oxygenation?). Breweries use medical grade O2 because its pure, sterile and dry; unlike compressed air unless you have a air drier and HEPA filter inline.