Oxygen contamination during preparation

[takkazama]

I've heard that oxygen inclusion during brewing leads to an increase in dissolved oxygen in the final product, but doesn't aeration after wort cooling for yeast growth lead to an increase in dissolved oxygen?

 

[Nosybear]

Nope, the yeast use that O2 quickly. Excessive splashing on the hot side ans O2 introduced after fermentation is what causes staling.

 

[Herm brews]

Welcome to this wonderfully informative forum. I hope you enjoy your brewing journey.
The yeast use that dissolved oxygen, so before fermentation oxygen in the wort is a good thing. It is after fermentation starts and finishes that you want to reduce exposure to air/oxygen.

 

[soccerdad]

There is an entire debate / discussion / argument around Low Oxygen Brewing or what some call LODO (low dissolved oxygen).
But really - if you are a new brewer understanding that oxygen ingress on brew day is OK, but after brew day is not is all you need right now.
Then read. And read some more. And then again. And more.
Your processes will adjust and modify with knowledge and experience.
This is a good place to bounce ideas off experienced brewers and hear their recommended readings.

 

[Minbari]

If it was bad people, my self included, wouldn't aerate the wort before pitching.
I use pure oxygen just before pitching and it really kick starts the fermentation.

 

[Daniel Parshley]

An O2 addition to the cooled wort gets the fermentation going quicker. I have used a bottling bucket and bottled from the fermenter. The bottling bucket batches carbonate quicker and some in as little as 5 days. Those quick to carbonate have been some of the best when using C hops (cascade, centennial, cashmere, and I would throw mosaic and amarillo in there, too). The browns and ambers seem to like the longer carbonation and conditioning times (and protection from O2). Those times I do keep most of the O2 out are noticeably longer to carbonate and the late dry hop additions seem to be waning in aroma and delicate tastes . Go for it and enjoy. They all were drinkable and tasty.

 

[Bubba Wade]

And there are those of us (probably in the minority) who don't worry about oxidation much at all. I don't oxygenate the wort, figuring there's enough nutrients in the wort and dry yeast to successfully complete fermentation. And I have very few problems. And I don't take too many precautions when transferring from the fermenter to the keg. I figure that during the natural carbonation process, the yeast will scavenge available oxygen prior to any noticeable side effects.

Lots of good reference information stated above by others, but yeast are a pretty resilient creature. Experiment with oxygen and without to see if you notice a difference.

 

[HighVoltageMan!]

Dry doesn't need aeration, it has enough lipid, sterol and glycine reserves to reproduce without any worry of petite cells or cell membrane problems. Liquid does not contain enough lipid and sterol reserves to reproduce properly without oxygen and often is lacking in glycine, so it stresses the yeast, especially if you have an under-pitch condition. The most common problems are under attenuation, slow starts, high alcohols, acetaldehyde (green apples), diacetyl (butter) and phenolic flavors, etc.

General rule of thumb for using oxygen (aeration) at pitch . Dry yeast doesn't need it, but it doesn't hurt anything. Liquid yeast, even liquid yeast harvested from a dry yeast fermentation, needs oxygen at pitch. All the nutrients are there in the wort that the yeast needs, except oxygen. That was driven off in the boil.

Liquid yeast needs oxygen at pitch.

 

[Bubba Wade]

Liquid yeast needs oxygen at pitch.

I used to use liquid yeast for all of my batches, but over the past 30 years, I’ve gradually switched to the dry as the quality and selection has greatly improved. I do remember using liquid yeast successfully without aeration provided I made a big starter. Have you had any experience with this?

 

[HighVoltageMan!]

I used to use liquid yeast for all of my batches, but over the past 30 years, I’ve gradually switched to the dry as the quality and selection has greatly improved. I do remember using liquid yeast successfully without aeration provided I made a big starter. Have you had any experience with this?

I used to use liquid yeast exclusively when I first started. I used to be a yeast snob, I thought dry yeast was inferior to liquid. I have changed my way of thinking. Some dry yeast is exceptionally good, I should have started with dry yeast, not liquid.

My first beers were done with only liquid and no aeration. I had phenolic flavors, beers were sweet and I'm sure there were other problems. Sometimes I got a decent beer, but the next time it was a dud. I started building the yeast up with starters and this made am improvement, but when I used oxygen and starters together the beers were way different from the past beers I made. Dryer, no sweetness and zero phenolics. I wasn't sure I like the lack of sweetness, but I soon realized that it was was a much better beer. From that point onward I was able to build on that and improved my consistency. I now detest sweet beers unless it's a RIS or something really big.

The best advice I could give to new homebrewers is use dry yeast. That stuff is as bullet proof as a yeast can get. Set it and forget it.

 

[Minbari]

I used to use liquid yeast for all of my batches, but over the past 30 years, I’ve gradually switched to the dry as the quality and selection has greatly improved. I do remember using liquid yeast successfully without aeration provided I made a big starter. Have you had any experience with this?

I just recently started using oxygen for liquid yeast. Up till that point, a good starter would still work. With oxygen, the lag phase is much shorter

 

[Bubba Wade]

I just recently started using oxygen for liquid yeast. Up till that point, a good starter would still work. With oxygen, the lag phase is much shorter

Do you think oxygenation requirements might vary between yeast strains?

 

[Minbari]

Do you think oxygenation requirements might vary between yeast strains?

no doubt it does. but it wont hurt to have too much on a strain that doesnt need it, vs not enough on a strain that does.

 

[Brewer #328232]

Excessive splashing on the hot side ans O2 introduced after fermentation is what causes staling.

I watched a DavidHeathHomebrew YouTube where he said that hot side aeration is only a concern in mass production scale. He didn't elaborate, but he seems to be pretty well informed and credible. Of course I always take "some guy on the internet" statements with a grain of malt (see what I did there ) Does anyone have any thoughts on this, yea or nay?

 

[Nosybear]

I watched a DavidHeathHomebrew YouTube where he said that hot side aeration is only a concern in mass production scale. He didn't elaborate, but he seems to be pretty well informed and credible. Of course I always take "some guy on the internet" statements with a grain of malt (see what I did there ) Does anyone have any thoughts on this, yea or nay?

Why would there be a difference? In fact, they have less area exposed to air per liter of wort than we do. I really want to get a DO meter and start testing some of these ideas at homebrew scale.

 

[Minbari]

I still say that oxygenation before fermentation is harmless. At least for the few minutes it exists.

 

[GFHomebrew]

It makes sense to me cut a banana or apple and watch it brown before your eyes!

Same as wort pre pitch if you left it in a sanitized flask it would darken.
Same as me leaving my post boil in my kettle until next day I'm imagining it would darken a bit too.

I dont have the desire to add a blanket of nitrogen ontop of the mash tun prior to boiling.
I believe for me the post fermentation limitation of Oxygen is more important but commend those more festidous OCD brewers who do go that next step.

There is also Ascorbic Acid
And Bisulpates meta and potassium that can be used as an anti oxidizer I'm messing with this in my brewing atm and look forward to some lite lagers this summer to you know taste test away with maybe even bottle some and store em for awhile and side by side ect ect.

Loving this discussion

 

[Mark Farrall]

Oxygen loves reacting with things. There's plenty on the hot side that it reacts with that will change the taste of the beer and make the beer go stale more quickly. Can we tell the difference in the beer between a low oxygen hot side approach and not? Haven't a clue and haven't read anything more compelling than there should be a difference (and sadly often wrapped around dismissive, you don't have the palate/experience to appreciate it nonsense).

There also seems to be a lot of extra effort for the LODO approaches that I've read. That effort and the lack of clear evidence has stopped me going down that rabbit hole, even though I agree that it should make a difference. There's so many rabbit holes and only so much time I'm prepared to give.

 

[Dornbox]

Nope, the yeast use that O2 quickly. Excessive splashing on the hot side ans O2 introduced after fermentation is what causes staling.

Are you saying hot side aeration can cause low attention / stalling?

Thanks!

 

[Donoroto]

Are you saying hot side aeration can cause low attention / stalling?

Thanks!

He wrote "O2 introduced after fermentation is what causes staling.". Key words 'after' and ' staling' (getting stale).