How much O2 into the wort before pitch?

[Trouble_Brewing]

OK, I've been trying to track down an answer to this, but am getting a lot of conflicting and confusing info. I know there is no one pat answer for all beers, but are there some guidelines for the amount of O2 to add to your wort before pitching yeast?

I'm getting an inexpensive O2 regulator from a brew shop. I plan to hook up an inexpensive flow meter so I can measure out how much I'm adding. But I'd kind of like to know what others are doing.

 

[IndyRob]

I usually just whip the wort around with my mash paddle until I get tired of doing it lol. I have tried an aeration stone and really never could tell a difference in start times.

The really big thing to be careful of is to wait for the temp to fall below 80 degrees F before you aerate so you don't add any oxidized badness to the hot wort.

 

[dstar26t]

I use 3 Lpm with a .5 micron stone at the bottom of a carboy. I also have a dissolved oxygen meter so I know exactly how much O2 is going in.
Here's my data so far:

Volume into the carboy varies, usually 5.5 gallons +/-.5 gallons depending on boil time and hop amounts.

 

[Trouble_Brewing]

dstar26t,
Thanks for the very useful information. I'm surprised more people haven't shared, as I though a lot of people were using 02. I was thrilled with the quality info you provided though.

Where did you get your oxygen meter and how much did it cost? Probably way more than I can afford, but it's worth asking.

What DO level are you shooting for? Have you noticed any plus or minuses to the batches with higher DO levels? 20 in an Ale seems high for example...

Anyone else: Even just sharing what you do is helpful, even if it's not precise. Hoping to not sound like a jerk; I'm only looking for O2 times/methods though, not other aeration methods.

 

[dstar26t]

This is the DO meter I have, the older SM600 model. It won't work for checking your DO level at packaging since it's accuracy is only +/-.3 mg/L...it's good to keep packaged beer around or lower than .3mg/L I've read.

Lower gravity ales I shoot for 8-12ppm (I'm assuming 1ppm = 1mg/L). The higher the gravity gets, the more O2 I use. The 20 ppm ale you see in the chart got dosed with sugar during fermentation giving it a 1.093 OG so I used a bunch of O2 at the beginning. I didn't get any hot alcohol flavors in it (I pitched for 1.093) but I wouldn't go higher than that either. I'm working on an excel equation that gives seconds of O2 based on wort volume, temp (to discern between ale/hybrid/lager) and gravity. I need a few more batches to get it dialed in.

Sorry the chart doesn't have any units...
Wort temp is Fahrenheit (obviously)
Oxygenation time is seconds
DO level is mg/L

 

[Trouble_Brewing]

Is that flow rate really 3L/minute? That seems pretty high. If so, then the assumptions made in BYO are way off. See this link.

Are you getting a lot of bubbles at the surface?

 

[dstar26t]

Yeah, I read that article, there's no experimental data relating to pure O2. My welding tank has a medical regulator on it. My only assumption is that it's flowing the rate it's set at. I get about 3/8"-1/2" of foam after oxygenating. Maybe I could turn it down? I use 3 Lpm because it's the closest setting I have to 3.5 Lpm which gave Wyeast these results:

 

[dstar26t]

Also a good read and lists dissolved O2 guidelines

The last paragraph under Oxygen (10 paragraphs down) suggests DO levels.

 

[Trouble_Brewing]

Aston Lewis recommends using a much lower flow rate, as low as .2LPM, which must be where the difference in the theoretical numbers he uses and the actual results you are seeing. I'm guessing the higher flow rate means more oxygen is escaping (more bubbles). Unfortunately the Wyeast rate is by visual estimate only, so it could be way off.

I'd be curious to see what you get with your DO meter if you tried a lower flow rate, say .5LMP or 1LPM.

Anyway I really do appreciate the real-world numbers you've provided, as well as the other info. I'll read the article you posted.

 

[ksbrain]

I have a little red O2 tank from the hardware store with a stone at the end of a tube. I put the stone in the cooled wort, and turn on the O2 as little as possible, and let it sit there for roughly around 60 seconds or until the foam reaches the mouth of the carboy, whichever is first. I might do more for a higher gravity beer like above 1.080. My procedure is not too precise, but seems to work well enough for me.

 

[Montanaandy]

I have debated getting a stone and o2 tank but I have found that just using a plastic aeration device at the end of my silicon hose while pumping the wort into the carboy usng my March pump has always produced enough aeration to give me the results that I am looking for. Montanaandy

 

[IndyRob]

I'm curious - What are your results using an aeration device vs regular splashing/shaking the wort or even nothing at all?

Do you find that your wort takes off faster this way or ferments more quickly?

I've been going off of some really old-school data with my beers and I remember a guy back in the '90s did a side-by-side test of shaking/stirring, aerating using a stone and nothing at all and found negligible results from the test.

The second thing I wonder is if the aeration of the wort prior to pitching affects the flavor - esters and fusel alcohol specifically as they seem to be the most common flavors yeast provide during the conversion process. I've been reading about this in some BJCP articles.

I've never tasted a side-by-side comparison of a non-aerated beer vs an aerated beer prior to pitch. It might be a catalyst for me to do an experiment but I'd like to see if the experts here have anything to share?

Thanks!
Rob

 

[Trouble_Brewing]

I'm curious - What are your results using an aeration device vs regular splashing/shaking the wort or even nothing at all?

I don't mean to sound like a prick, but I didn't start this thread to debate aeration vs oxygenation, or even different aeration methods. If you don't understand the the difference between aeration and oxygenation, then let me clarify for you.

Aeration = using air to increase the level of oxygen in solution. Since air is only around 20% oxygen, there is a finite limit to how much oxygen you can get into solution using air alone (8pmm).

What I'm talking about is using pure oxygen. Big difference. You are able to reach much higher levels of dissolved oxygen, up to around 40ppm.

Wyeast recommends between 10-12ppm for ales, and even more for lagers. What I'm trying to find out is what the guidelines are for using oxygen to reach those levels.

So if you use oxygen, are you just turning it on for a set time, say 60 seconds, or are you using a flow meter to determine the rate vs time? If you vary the amount or time, what criteria do you use? Lagers vs Ales, original gravity, temperature?

If you want to know whether shaking the carboy is more effective than using an aquarium pump, do a search. There's plenty of info on that topic, and very little controversy.

 

[michael.berta]

JZ & Palmer did a brew strong on aeration. I'm pretty sure he said one liter per minute flow rate for one minute for Ales and slightly more for lagers... But you may want to listen to the podcast to double check...

http://www.thebrewingnetwork.com/shows/589

 

[Trouble_Brewing]

I'll go back and listen to it again, but I seem to recall them leaving it pretty vague. Their summary was to "experiment to find what works best for you". That doesn't give me much of a starting point, and I don't repeat the same recipes enough to get any kind of reliable comparison.

That particular episode ended up kind of weak from what I remember. I sorta understand why, as I'm sure they don't want people holding to what they say as "the answer" and quoting it word-for word as complete fact. But sometimes they need to be less cautious and give more specific starting points, IMHO.

But I will give it another listen to see if I get more the second time around.

 

[IndyRob]

I don't mean to sound like a prick...

I apologize if I offended your sensitivities.

I've seen oxygenation and aeration used interchangeably quite often even if incorrect and I now realize I was as well.

I'll take your advice and look elsewhere for information.

 

[dstar26t]

Couple more data points for you. I brewed a kolsch over the weekend and it sat for 18 hours before O2 and pitch. I kept with the 3 Lpm and with one carboy 35 seconds gave 11.9 ppm and the other I used 25 seconds which gave 9.9ppm. Both carboys were at 60F and 1.0485 OG.

 

[dstar26t]

Updated the data:

 

[greenbirds]

Thanks for the update, dstar. I know a lot of people use a valve without a regulator, preventing accurate comparison to your data, but at least this gives some frame of reference.

I've always just opened the valve all the way and let it rip for 30-60 secs depending on gravity and whether it's ale or lager. I think your results at 3L/min give me some idea of what I'm actually getting.