oxygenating wort - larger capacity systems

[Agentgonzo]

Just because someone doesn't do it your way or believe in the same things as you do, doesn't mean it's second rate. Sheesh!

Well if Brulosophy is your mentor good luck to you

They aren't. But feel free to keep making things up about people to argue against .

 

[Sadfield]

Different yeasts have different nutritional requirements. Kveiks for example, require nutrient when brewing low gravity, because they are selectively used to high gravity worts. More grain = more nutrients.

 

[foxy]

Just because someone doesn't do it your way or believe in the same things as you do, doesn't mean it's second rate. Sheesh!

They aren't. But feel free to keep making things up about people to argue against .

I don't give a fig about how people go about their brewing, but I do know hoppyscotty does so the more beneficial tips I can give him I will.
Doesn't matter to me what people believe in, believing in Brulosophy just proves to me the lack of intelligence of the brewers that do.

 

[peebee]

As others who have been saying this: I don't aerate wort going into my 30L fermenter. Whether dry or liquid (but for liquid I always use a starter, and do not attempt to deprive it of access to oxygen on the stir-plate as some do).

But I too have a larger 65L fermenter, and I do oxygenate the wort going into this (about 45-second blast pure O2 through a sintered stainless steel "stone"). And I do this for a very simple reason: I talked myself it needing it ages ago and acquired a big cylinder of O2. A big cylinder is a lifetime's supply of O2. And I still need to get rid of what I've got (impossible!). It does no harm, so I continue using it.

As for dried yeast: I was made aware (by things going wrong) that some packets do not contain sufficient viable yeast to ferment the beer well. Either because I've kept them too long (but they are still "in-date") or they never contained sufficient in the first place (cheapskate 10g packets) or, as in my case, both!

Make sure you use enough!

This from Mangrove Jack's site (who bang out 10g packs):

In our yeast guide, we mention that for ales above 1.050 gravity to pitch 2 packets of yeast. For lager strains, we recommend 4 packets if the gravity reading is above 1.050. Based on a 23L fermenter volume​

The higher amount for lager is only because lower temperatures may be used for fermentation.

 

[peebee]

... They aren't. But feel free to keep making things up about people to argue against .

Stop! Leave Foxy alone! He might not have done any "anger management" but that's not a good excuse to wind him up

 

[Stevieboy]

I've never understood the need to aerate wort - after all isn't fermentation an anaerobic process? What benefits does it (purportedly) bring?

 

[Agentgonzo]

I've never understood the need to aerate wort - after all isn't fermentation an anaerobic process? What benefits does it (purportedly) bring?

Lots of info on the forums/internet, but in short, it builds up yeast reserves (sterols) that mean when it multiplies in the first (12?) hours, you end up with healthy yeast rather than weak yeast. Dried yeast (see Fermentis link above) is bred so that they have all the sterols they need. Liquid yeast isn't (I don't know why).

Benefits are faster fermentation, fewer off flavours and better attenuation.

 

[peebee]

I've never understood the need to aerate wort - after all isn't fermentation an anaerobic process? What benefits does it (purportedly) bring?

Yeast needs the oxygen to grow. But it will also "put aside" any excess oxygen for growing later (hence dry yeast doesn't need it - or well oxygenated yeast starters). But "starved" yeast (direct pitched liquid yeast) probably does.

 

[peebee]

Dried yeast (see Fermentis link above) is bred so that they have all the sterols they need. Liquid yeast isn't (I don't know why).

I wondered this a while ago ...

They do something weird with yeast ahead of drying; "fermenting" below the "Crabtree" threshold so the yeast actually does use aerobic respiration ... or summit like that. I guess this isn't appropriate for liquid yeast. But a well aerated liquid yeast starter, built to (hopefully) an adequate cell-number, will be okay.

No-one has said it, but: A starter will aerate adequately on a stir-plate. The outflow of CO2 from the starter won't prevent that aeration. Because ... if you leave the starter until it is fermenting that strongly to produce so much CO2, you've left it too long!

 

[Druncan]

I add bottled water 30mins to dry yeast and match FV temps. Always did the shaky-shaky with my 30L Speidels. Get the choons on blasting!

Now I get the wort below 23*C -for ale yeasts then plug in the pump with the CIP head on and let it rip for 3 mins on 75L and 150L FV's and chuck in pre-started yeast.

I'll be using a carb stone and my o2 cylinder on my 300l FV next for the first time. Sadly I just don't have the expensive kit to measure oxygen saturation levels. So I'll be using @foxy 's method with a flowmeter.

Yeasties in my brews tend to start munching same day as I watch for bubbles in the blow off and attenuate to plan. Lager gets the same treatment with double batches of yeast and 10*C max. My brews sell out so I'll keep to what works

 

[peebee]

I add bottled water 30mins to dry yeast and match FV temps. Always did the shaky-shaky with my 30L Speidels. Get the choons on blasting! ...

I can't imagine you in 30L Speedos.

No photos ... please!

 

[Weizenberg]

It is possible to harm yeast with too much O2. Values above 30ppm are considered undersirable for brewing (source: L Narziß, W Kunze).

My pitching temps are 5C and main fermentation 9C.

I use compressed O2 and a venturi tube used for fertilizers (cheap, ebay) to aerate in-line during transfer to the fermenter.

I aim for Oxygen saturation of about 8-14 ppm and control it with a DO meter.

 

[Sadfield]

It is possible to harm yeast with too much O2. Values above 30ppm are considered undersirable for brewing (source: L Narziß, W Kunze).

I don't know, but I'd guess that if you put in too much oxygen, that would be undesirable, in preventing or delaying the yeast from moving from aerobic to anaerobic respiration.

 

[Druncan]

@peebee
"I can't imagine you in 30L Speedos. No photos ... please!"

I'm hurt, XXL Mankini any better?


@Weizenberg - Please advise what meter and how you calibrate it? -really interested

 

[peebee]

I don't know if I sparked of those two related comments above, but I would deserve a rebuke for what I wrote:

It does no harm, so I continue using it.

Yes, excess O2 can do harm, I'm only making that comment based on what I'm doing (which would add <10ppm O2 ... approximately!).

But it does illustrate a related question:

What happens with that (marginally) excess oxygen when the yeast never really needed it to do the job? I only presume it just ends up as more yeast than is strictly necessary?

 

[Agentgonzo]

What happens with that (marginally) excess oxygen when the yeast never really needed it to do the job? I only presume it just ends up as more yeast than is strictly necessary?

I'm only guessing here, but my assumption is that the yeast buds/grows/multiplies as normal. And after it's grown/budded/multiplied a bit, the new generation of yeast will be capable of using more oxygen and will this use up this excess oxygen in your wort, and yes - ends up as more yeast

 

[foxy]

What happens with that (marginally) excess oxygen when the yeast never really needed it to do the job? I only presume it just ends up as more yeast than is strictly necessary?

Any oxygen which is left over when the yeast goes into anaerobic mode gets scrubbed from the fermenter by the co2.

 

[Sadfield]

Any oxygen which is left over when the yeast goes into anaerobic mode gets scrubbed from the fermenter by the co2.

How does it go into anaerobic mode if there is oxygen? Isn't the definition of anaerobic respiration, respiration in the absence of oxygen? Don't living organism always favour aerobic, as it's around twenty times more efficient at releasing energy?

 

[foxy]

How does it go into anaerobic mode if there is oxygen? Isn't the definition of anaerobic respiration, respiration in the absence of oxygen? Don't living organism always favour aerobic, as it's around twenty times more efficient at releasing energy?

Yeast was on earth before the earth started producing oxygen, I believe it could be something to do with the drop in pH which is the trigger. Not sure on that but I believe it is something like that.

 

[Sadfield]

Yeast was on earth before the earth started producing oxygen, I believe it could be something to do with the drop in pH which is the trigger. Not sure on that but I believe it is something like that.

It can't be. Lactate is the byproduct of anaerobic fermentation. The pH doesn't drop until it makes the switch.