Are milk frothers suitable for aerating wort?

[Yirg]

Propeller-type milk frothers seem like a very easy solution to aerate wort. Has anyone tried this method? Any downsides?

Thanks!

 

[CascadesBrewer]

I am not sure what a "Propeller-type milk frother" would be. What size batch are you brewing? I have read of people using a metal paint stirrer and a drill, which seems like an interesting option. I don't use it much these days, but I have a simple kit that uses an air stone and an aquarium pump.

 

[NathanYearout]

Should be fine, I normally opt to just aerate it with a kitchen whisk I sanitized. Give it a vigirous stir for like 30 seconds to a minute and get some foam on top.

 

[Yirg]

I am not sure what a "Propeller-type milk frother" would be.

The one I have looks like this:

What size batch are you brewing? I have read of people using a metal paint stirrer and a drill, which seems like an interesting option. I don't use it much these days, but I have a simple kit that uses an air stone and an aquarium pump.

My next batches are 1 gallon, but I'll also brew 5 gallons again. Previously I either used a plastic paddle to aerate the wort or just rocked the fermentation container back and forth for about 20 or 30 seconds. I almost never have issues with fermentation and in the very few cases where fermenration was "lazy" I'm not sure lack of aeration was the reason.

If aeration is mostly important in the beginning of fermentation, won't it be sufficient to focus on the upper layer of the wort (where the yeast is sprinkled) and not worry to much about what's below? If so, then a small frother like mine should probably be sufficient even for larger 5 gallon batches.

 

[mashpaddled]

From the shape and size of the plastic propeller I'd be surprised if you can get enough air into the beer to make a meaningful difference. A milk frother like that works from forcing air into milk and creates a vortex to mix the air into small bubbles that stabilize as a froth in the solution. I'd think it would be hard to both inject enough air into the wort and create enough vortex to adequately mix it into solution.

I'd say try using it on like a gallon of water with a few drops of dish soap. If it struggles to create foam in one gallon it's going to be far less effective on five gallons.

 

[Elric]

Milk frother would be too small to really do anything, but a hand blender on full power, that would probably do a darn good job!

 

[Kickass]

You might need all your buddies to come over with their milk frothers and have a wild party...frothing your wort.

 

[Golddiggie]

Just keep in mind, using atmospheric oxygen levels to oxygenate your wort is limited to how many ppm you'll get. While it can be 'fine' for lower OG brews, once you start making bigger beers (where it matters far more) you won't be doing enough.

 

[Elric]

You might need all your buddies to come over with their milk frothers and have a wild party...frothing your wort.

I’m now picturing them all with lil glow brac and necklaces and they oxygenate the wort so well it turns into a foamparty

 

[GrogNerd]

I use a 5-gallon paint stirrer attached to the end of a power drill

works great.

$9 at the Orange Store

 

[Yirg]

Thanks for the suggestions, but one thing is still not clear to me - do you really need to aerate the whole wort or just the top layer where you sprinkle the yeast (I use dry yeast)? If it's just the top layer, then even a milk frother should be sufficient to create enough foam.

 

[VikeMan]

Couple of things here.

Foam is a byproduct of aeration, not the goal. That foam is foam that you ultimately won't get when pouring the finished, carbonated beer.

The goal is to get oxygen into solution. The problem with doing that with a "frother," propeller, paint stirrer, whisk, any other method that uses agitation to capture atmospheric O2 is that it will be limited to about 8-9 parts per million, which is generally less than ideal. The reason it's limited is that once that 8-9 ppm is reached, further agitation releases O2 back into the air as fast as it's being absorbed, because it is has reached equilibrium.

 

[Golddiggie]

Thanks for the suggestions, but one thing is still not clear to me - do you really need to aerate the whole wort or just the top layer where you sprinkle the yeast (I use dry yeast)? If it's just the top layer, then even a milk frother should be sufficient to create enough foam.

When I was oxygenating after putting the wort into fermenter, I used a stone on wand that I sent deep into the wort. Basically either at/on the bottom or damned close to it. Now I oxygenate the wort as it leaves the plate chiller (more even infusion).

For the question posted, you need to infuse the entire batch with oxygen. Doing 'just the top layer' is next to useless.

As also mentioned, using a manual method (agitating the wort) will only get you so far (the 8-9ppm levels). There's simply not enough oxygen concentration in the atmosphere to give you more. That's why a good number of us use pure O2 for the oxygenation of the wort. I use a bottle from a welding gas supplier (have had it for several years now). Using a regulator that allows you to set the flow rate (in liters per minute) is optimal. The regulators for the little red bottles has NO gauge or way to select the flow rate, other than 'best guess'. Makes it easy to under oxygenate your wort with that system. Also means you have NO idea of how much O2 you're using, or what's left in the tank. IIRC, I used that type of source for a couple of batches before tossing it aside and getting my current regulator and tank setup.

 

[Yirg]

Foam is a byproduct of aeration, not the goal. That foam is foam that you ultimately won't get when pouring the finished, carbonated beer.

Of course the foam is not a goal, it will obviously dissipate at a later stage, but after "frothing" it should stay for a while. Isn't the foam a more oxygen-rich bed for the sprinkled yeast than regular wort?

BTW, a brulosophy experiment that compared pure oxygen aeration vs. nothing
resulted in beers that were "incredibly similar" (but distinguishable by most testers), and another experiment that compared pure oxygen vs. shaking the fermenter resulted in beers that most testers couldn't reliably tell apart. This makes me think that perfect by-the-book aeration might be somewhat overrated.

 

[VikeMan]

Of course the foam is not a goal, it will obviously dissipate at a later stage, but after "frothing" it should stay for a while. Isn't the foam a more oxygen-rich bed for the sprinkled yeast than regular wort?

If you're talking about air trapped in the bubbles, as opposed to actually dissolved in the wort, the yeast can't use that O2. And the foam actually makes it harder (longer) for yeast to rehydrate.

BTW, a brulosophy experiment that compared pure oxygen aeration vs. nothing
resulted in beers that were "incredibly similar" (but distinguishable by most testers), and another experiment that compared pure oxygen vs. shaking the fermenter resulted in beers that most testers couldn't reliably tell apart.

It's only n=1, but did you notice that in the "NOTHING VS. PURE OXYGEN" experiment that the non-oxygenated beer finished three gravity points higher? (And that recorded measurement gap is generously small if you look at the actual pics.)

And in the "SHAKEN VS. PURE OXYGEN" experiment, there is no mention of how much O2 was actually added. "2 minutes" is meaningless without a flow rate. And, they used a 1.053 wort. Hardly chosen to try to reveal any potential differences. Even so, the result of the triangle testing was that 9 tasters, p=0.36, chose correctly. Assuming there's no detectable difference, there was only a 36% chance that at least 9 would get it right. But they did. The writeup should say "This result is virtually meaningless and the experiment should be repeated with a higher number of participants to increase the power." But it doesn't, so people quote it (and lots of other Brulosophy experiments) as having proved something.

This makes me think that perfect by-the-book aeration might be somewhat overrated.

It's one factor among many. But I submit that the little stuff adds up.

 

[Yirg]

If you're talking about air trapped in the bubbles, as opposed to actually dissolved in the wort, the yeast can't use that O2. And the foam actually makes it harder (longer) for yeast to rehydrate.

That's an interesting point. Maybe it would be more effective to add the yeast, then froth?

It's only n=1, but did you notice that in the "NOTHING VS. PURE OXYGEN" experiment that the non-oxygenated beer finished three gravity points higher? (And that recorded measurement gap is generously small if you look at the actual pics.)

The difference in another experiment was 9 points yet the majority couldn't reliably tell the difference. Maybe a larger sample of testers is needed, but for lack of better experiments we'll have to settle for brulosophy. To me their experiments are still more useful than common knowledge that's never put to the test.

Specifically for the "SHAKEN VS. PURE OXYGEN" experiment, your criticism is valid, but I don't think the point you raise make the experiment "virtually meaningless". Of the 21 testers, 9 could tell the different, but among them only 2 were very (or absolutely) confident in their selection. If the difference was that significant, I'd expect the number of them to be much higher. And I'm pretty sure that 2 minutes of pure oxygen at any flow level is more than I'm ever going to achieve with 20 or 30 seconds of rocking the fermenter back and forth (which is what I've been doing so far).

 

[VikeMan]

The difference in another experiment was 9 points yet the majority couldn't reliably tell the difference.

Why do you think they couldn't tell the difference? ls it because the writeup used these words? "In order to reach statistical significance given the sample size, 11 participants (p<0.05) would have had to accurately select the high mash temp sample, though only 9 (p=0.134) were capable of doing so, implying a general inability for people to reliably distinguish between a beer mashed at 147°F from another mashed at 161°F. "

Those are some seriously misleading words. The result doesn't support the words, or at least what people will take away from those words. With p=0.134, if there were no detectable difference, there was only a 13.4% chance that at least 9 would have got it right. Would you take those odds to Vegas and bet straight up on "no difference?" I sure wouldn't.

Specifically for the "SHAKEN VS. PURE OXYGEN" experiment, your criticism is valid, but I don't think the point you raise make the experiment "virtually meaningless". Of the 21 testers, 9 could tell the different, but among them only 2 were very (or absolutely) confident in their selection. If the difference was that significant, I'd expect the number of them to be much higher.

In triangle testing, it matters not at all how confident they were or weren't. Probability makes it unlikely for the testers to beat the odds by much by pure guessing.

And I'm pretty sure that 2 minutes of pure oxygen at any flow level is more than I'm ever going to achieve with 20 or 30 seconds of rocking the fermenter back and forth (which is what I've been doing so far).

Why are you pretty sure of that? It's not the case. EDIT TO ADD: But the experiment wasn't about 20-30 seconds of rocking anyway, so how much you personally rock your wort isn't relevant to the outcome of the experiment.

But, why are you only rocking the fermenter for 20-30 seconds? You're getting less oxygenation than you could, even without pure O2. I mean, its your beer, but if I didn't have a source of pure O2, I'd be shaking the bejeezus out of the wort.

 

[belgabrewing]

Thanks for the suggestions, but one thing is still not clear to me - do you really need to aerate the whole wort or just the top layer where you sprinkle the yeast (I use dry yeast)? If it's just the top layer, then even a milk frother should be sufficient to create enough foam.

I have been using 1 drop (yes 1 drop) of olive oil from a sanitized eye dropper for years instead trying to oxygenate my wort. Here is a link: Olive Oil in Beer Fermentation Instead of Oxygen - Winning Homebrew

 

[Kickass]

Maybe it would be more effective to add the yeast, then froth?

Ditch the frother concept already.

Unless it gives you piece of mind, then use. All good breweries operate on at least one good piece of superstition. Frosty Frothy’s does have a catchy tone too...

 

[Golddiggie]

Most breweries also infuse O2 into the wort as it leaves the plate chiller. Making it less labor intense than many home brewers. Sure as hell less than trying the shake method (or using atmospheric oxygen).

Yeast will have a shorter lag time with pure O2 than without. Or with enough oxygen than without. IME, the reduced lag time, better fermentation, and zero negatives were more than enough reason to keep using pure O2. Not to mention being far easier on me.

 

[VikeMan]

I have been using 1 drop (yes 1 drop) of olive oil from a sanitized eye dropper for years instead trying to oxygenate my wort. Here is a link: Olive Oil in Beer Fermentation Instead of Oxygen - Winning Homebrew

I'm not saying that olive oil isn't a good way to do it for at least some situations. But whenever this topic comes up, I feel compelled to mention that New Belgium (the brewery that supported the experiment), whether in spite of or because of the results, did not switch from oxygen to olive oil in production after the experiment. My guess (and it's only a guess) is that they got higher esters with olive oil than with O2.

 

[Yirg]

I have been using 1 drop (yes 1 drop) of olive oil from a sanitized eye dropper for years instead trying to oxygenate my wort. Here is a link: Olive Oil in Beer Fermentation Instead of Oxygen - Winning Homebrew

Interesting method. I wasn't aware of this option. Isn't 1 drop about 1000 times more than needed (as recommended in the article)? Have you noticed any downsides using this much oil, compared to adding oxygen?

 

[marc1]

Thanks for the suggestions, but one thing is still not clear to me - do you really need to aerate the whole wort or just the top layer where you sprinkle the yeast (I use dry yeast)? If it's just the top layer, then even a milk frother should be sufficient to create enough foam.

I haven't used dry yeast for a while, but I remember that it specifically did not need to have the wort oxygenated at pitch. Are you sure you need to do this?

 

[belgabrewing]

Interesting method. I wasn't aware of this option. Isn't 1 drop about 1000 times more than needed (as recommended in the article)? Have you noticed any downsides using this much oil, compared to adding oxygen?

No issues with head retention or anything flavor related, just great beer without the possibility of contamination/infection of my wort with the oxygen apparatus.

 

[VikeMan]

No issues with head retention or anything flavor related, just great beer without the possibility of contamination/infection of my wort with the oxygen apparatus.

How are you sanitizing the oil?

 

[KyBeer]

I just finished a test to determine if the expense of oxygen injection in wort would justify the cost.
I brewed an 8 gallon NEIPA, 1.054. I used a US05 in a starter that was started from 800 ml of wort and 800 ml spring water. I added light DME to bring the SG to 1.040. About 30+ hours on a stir plate and the yeast was happy. The carboys were filled each to the same level and the yeast was divided evenly. Fermentation was done in a controlled environment at 65-66 F.
One carboy was only filled my old way by pumping the wort in quickly. Lots of splashing and foam. The second was filled slower but passed through a tee connector with a stone on one port. I added O2 until I saw bubbles in the line. I know I have no idea the volume of oxygen, but the goal was to see if there was any difference in fermentation.
The non-oxygenated wort started working in about 18 hours, 6 hour behind the oxygenated wort. The oxygenated wort/beer finished almost two days sooner. I let the beer set until the bubbler stops and the top of the beer has mostly cleared.
Both are kegged and carbonated. Not my favorite beer but they both taste very close. Maybe a slight difference in mouth feel and dryness. Or maybe I'm looking for something that's not there. I will have to taste each several times over the next two week to know for sure.
Would I add O2 to the wort? If I don't have O2 it would not stop me from brewing. If I am brewing for competition I would add O2, just to make sure the yeast was happy.

 

[Golddiggie]

IMO/IME, being able to set the actual flow rate of the O2 going into the wort is a key aspect of using pure O2. The dumb regulators (as in no way to actually tell the flow rate) on the red cylinders is a poor choice at best. Knowing how much O2 you're pushing through a stone is far better. If you hunt around, you can get the regulator that will connect to a welding gas O2 bottle pretty easily. Or at least I did when I bought the ones I have.

I don't watch for oxygen bubbles in the wort as it goes over the stone. Mostly because that's in a stainless T fitting (TC connections) so it's in the dark. I know that with the regulator opened up to the selected Lpm mark, and the valve at the O2 stone opened, I'm getting that much O2 into the wort.

IIRC, from the Yeast book, proper O2 levels in the wort let the yeast replicate with healthy cell walls. Less O2 levels means the cell walls are not as healthy/strong as they could be. You'll still get beer out if the yeast, but they'll be stressed less than if they had more O2 to use.

While the impact for lower OG beers will be reduced, once you pass a certain OG level, the need for proper O2 levels is higher. I just include it in my process for a couple of reasons.
One. It's easy to do since the O2 stone is in the assembly that controls wort flow out of the plate chiller.
Two. With the welding gas bottle (20cf IIRC) I have plenty of O2 on hand.
Three. Keeping it as a standard process/step means I'm less prone to skip it where it's more important/critical.

I have a gas ball lock post on the O2 regulator and the matching QD on the O2 stone. So it's easy to connect them together. I made the adapter to get the O2 regulator to have the post installed. Mostly because I couldn't locate an already made fitting that would do the task. I had plenty of brass stock on hand to use to make it.

 

[VikeMan]

While the impact for lower OG beers will be reduced, once you pass a certain OG level, the need for proper O2 levels is higher. I just include it in my process for a couple of reasons.
One. It's easy to do since the O2 stone is in the assembly that controls wort flow out of the plate chiller.
Two. With the welding gas bottle (20cf IIRC) I have plenty of O2 on hand.
Three. Keeping it as a standard process/step means I'm less prone to skip it where it's more important/critical.

Of course, you can (and maybe you do) vary the amount of O2 based on gravity (and perhaps other considerations). That's what I do and recommend.

It's a common misconception that it's impossible to over-oxygenate wort. But oxygen beyond what the yeast can remove has no choice but to begin oxidizing the wort. (Full blown LODO folks use dissolved O2 meters to determine when to stop, based on their pitch rates and/or gravity.)

 

[Golddiggie]

Changing the amount of O2 going into the wort is why I have the regulator that allows for that. It has stops at every 1/2 Lpm level of infusion. I do, typically, use lower levels for lower OG brews. Bigger beers get a higher level. I need to do a test run with my new plate chiller to see what kind of chill time I'll be looking at with it. I suspect I'll be looking at a few minutes to fully chill 8-10 gallons of 195F wort to pitch temperature (new chiller is over twice the surface area of the old one). Which means I could be looking at increasing the O2 flow rate moving forward. Old plate chiller hit pitch temp (inside conical) in less than seven minutes from start of flow through the chiller. Gotta love the temperature of the water coming from the well. Even more so when you don't run it through a hose outside the house (other benefits when winter brewing of NOT dealing with a frozen/plugged up hose).