aerating the wort

I see on most recipes they say to aerate the wort before pitching yeast, has anyone ever just poured the wort from one bucket to the other several time? Will this (Aerate) the wort ok, or would it be overkill? whats the best way yall have found to do this? thanks

I think the accepted best way is to use a pond/aquarium aerator stone and pump, or ideally oxygen canister (get them from a brew shop - not all will work for beer).

Personally, I don't bother though - I just stick the stirring paddle in an electric drill and thrash the hell out of the wort for a couple of minutes.

Other people seem to like to shake the carboy, though that always seems like a good way to end up with your kitchen covered in wort and broken glass.

I bought the little guy pictured below. I use it on the end of my siphoning tube. After that, I put the lid on the bucket and shake the **** out of it. Seems to be working fine. I hope you don't mind, but I have a quick question involving aeration and I'd like to just tag it on to this thread:

How necessary is a "perfect" aeration. Does it effect the flavor or just how long the yeast take to get fully active? I didn't know about aeration during my first 2 brews and they didn't get aerated at all, but seemed to turn out just fine.

seefresh said:

I bought the little guy pictured below. I use it on the end of my siphoning tube. After that, I put the lid on the bucket and shake the **** out of it. Seems to be working fine. I hope you don't mind, but I have a quick question involving aeration and I'd like to just tag it on to this thread:

How necessary is a "perfect" aeration. Does it effect the flavor or just how long the yeast take to get fully active? I didn't know about aeration during my first 2 brews and they didn't get aerated at all, but seemed to turn out just fine.

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Aeration is mostly about yeast health, your aerating provides valuble nutrients for cell reproduction. It matters by way of preparing the proper environment for yeast to gather "momentum" for fermentation, it also may enhance the speed in which the yeast begin fermenting. I think with proper amounts of aeration in the wort prior to pitching, the yeast can reproduce in this highly aerated state much faster, without getting "tired".

It sholdn't have much to do with taste quality.

lgtg said:

Aeration is mostly about yeast health, your aerating provides valuble nutrients for cell reproduction. It matters by way of preparing the proper environment for yeast to gather "momentum" for fermentation, it also may enhance the speed in which the yeast begin fermenting. I think with proper amounts of aeration in the wort prior to pitching, the yeast can reproduce in this highly aerated state much faster, without getting "tired".

It sholdn't have much to do with taste quality.

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Cool, thanks for the reply. Just wondered.. could bad aeration be a cause for the yeast not reaching full attenuation?

I aerated for the first time this batch with an oxygen bottle and 5 micron stone. The beer was done in the primary in 3.5 days. I had almost immediate fermentation. At Day 2 the fermentation was almost violent. And this was with my first full boil AG recipe.

Previous batches that lacked the pure o2 did not ferment as quickly or violently and had a longer lag time.

For $35 the O2 aerator was as good of an investment as a wort chiller.

I understand the concept to be this; Oxygen puts yeast into a reproductive state and allows the cells to store energy for the fermentation process.

The million dollar question is how much O2 do they really need? My followup to that question is how many yeast cells are you initially pitching and how much attenuation are you expecting? There are so many variables.

If you watch the video in my sig, you'll find that higher O2 levels likely allow for fuller attenuation. You'll also see that the simply shaking method seems to be "good enough" as most people will attest. I'll probably run another batch and test some other variables in the near future.

Hey Bobby_M, I've watched your video before, very cool, but I got a question. Was the FG different on all of them? Or did they end up the same?

The FG results I have were after 144 hours and I never thought to take another reading (another potential flaw in the experiment). I suppose all three batches could have ultimately settled into the same gravity but I doubt it. After the initial staggered lags, the O2 injected wort always stayed a couple points lower than the rest. Of course, I'm jumping to conclusions so I'll be sure to take a final gravity before "disposing" of the samples.

This idea comes from Mike. An owner of a local homebrew shop I go to. I haven't made one yet but plans are in the works.

http://www.frugalwestallis.com/index.php

Venturi Tube Wort Aerator


Ever wonder what to do with those old yeast vials sitting around the brewery? I dont. Turn one into a Wort Aerator. If you noticed, they fit the neck of your carboy very well, and screwing the cap onto it keeps it from falling into the carboy. Remember, this item must be used in a vertical position or it will leak wort from the tube, its a gravity thing.

http://www.kettlemoraine.com/mikesbeerpage/images/aerator1.jpg


Heres what you do. Take a 6 inch length of tubing ( vinyl, copper, brass, or stainless depending on your fabrication skills ), drill 4-6 small holes, about .020" diameter into the center 1.5" of it. I used a spiral pattern for the holes, believing that it causes more turbulence, but the aerator tube will work fine with holes period. Drill a hole in the top and bottom of the vial to pass the tubing through, make the hole small enough to fit the tubing snugly. Drill some more small holes for air entry into the cap of the vial, I settled with four one-eighth inch holes. Put a cotton ball just under the lid, this is to be an air filter to keep contaminates out of your wort as it draws the air through and into your wort.

No need to spend money on oxygen bottles or cleaning of those difficult airstones anymore! This is the brewers favorite price point here.... free oxygen! Only one very small warning, if you drill the aerator tube holes too large, wort will leak out of the holes and fill the vial over time. You need to pay attention to the vial if you are allowing pressure to build in the carboy (too tight of a fit in the carboy), wort will fill the vial, soak the cotton and quit working. I now am drilling a 1/16 inch pressure relief / drain hole in the bottom of the vial where it is inside the carboy, venting the air under pressure in from the carboy. They work well in usage, especially if you use a rubber band around the tube to raise it in the neck of the carboy, as I have been suggesting, to increase the fill space in the fermenter before the aerator touches the wort.

WARNING: Do not use this item unsupervised, as you will need to be around to shake down the foam as your fermenter fills, or it will overflow with frothy wort.

Since I started using this device on every beer, I have not had ONE beer finish with high terminal gravities. No stuck ferments, no problems, even when I underpitched my yeast. These are also able to be autoclaved if you use metal tubing.

Follow this picture and you should get one of these sweet gadgets done in less than one hour.

(BELOW) Heres a look at the holes drilled into the tube, there are 4 holes in a spiral around the tube. Only two are shown. There is also a ring of holes in the lid to let aeration air in through the cotton ball filter. More holes than needed (8) are in the shown part. You could use half (4) of that. If you still need to use your oxygen / airstone unit, blast your wort at about 4 hours post pitch, and again at 12 hours, this will give yeast some boost when it needs it according to the yeast doctors.

http://www.kettlemoraine.com/mikesbeerpage/images/aerator2.jpg

A large enough starter will nullify the aeration technique you use. The amount of yeast and it's attenuation decide your FG, not whether or not you used pure oxygen or didn't shake it at all.

In any high sugar environment, like wort, yeast would rather produce alcohol over cell reproduction. The violent and quick "fermentations" observed by oxygen setups is just gases coming out of solution, not fermentation. Pitching yeast into a low oxygen environment is what actually starts alcohol production the quickest. Of course if you didn't start with enough yeast cells, what yeast you did pitch may not have enough energy to complete fermentation.

The way I see it is why waste money on a oxygen setup to grow yeast when you can make more yeast by adding pennies worth of DME? Oxygen setups can be chalked up in the toy category, it may be cool to have, but money can probably be better spent elsewhere.

There's a really good interview with the guy from Wyeast about areation on BasicBrewing Radio. He says that the best way is pure oxygen with an airstone for a couple minutes at a slow trickle. The second best way is shaking the heck out of the carboy.

I find the bucket to bucket technique to be fast, easy and very effective.

McTarnamins said:

I aerated for the first time this batch with an oxygen bottle and 5 micron stone. The beer was done in the primary in 3.5 days. I had almost immediate fermentation. At Day 2 the fermentation was almost violent. And this was with my first full boil AG recipe.

Previous batches that lacked the pure o2 did not ferment as quickly or violently and had a longer lag time.

For $35 the O2 aerator was as good of an investment as a wort chiller.

Click to expand...

Temperature is probably the biggest variable as far as speed goes. If you didn't control for temp, your 'study' is invalid.

So you don't think cell count has no effect on how quickly they get through the fermentation? I think it's a big factor and it's supported by how quickly a batch will ferment when pitched on a yeast cake or with a large starter.

Do you think my aeration experiment results are false?

seefresh said:

How necessary is a "perfect" aeration. Does it effect the flavor or just how long the yeast take to get fully active? I didn't know about aeration during my first 2 brews and they didn't get aerated at all, but seemed to turn out just fine.

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From "Tap into the Art and Science of Brewing":

Yeasts can be classified in yet another way—according to the amount of
oxygen they require before they will ferment wort efficiently. Some are satisfied
when the Brewer “air-saturates” the wort—bubbles air into the wort
after cooling, which introduces approximately 8 ppm. Some strains are happy
with half that level, while others demand oxygen saturation (16 ppm), and
yet others aren’t even satisfied with this amount of oxygen.

So, the less than useful answer is that it depends on which yeast you are using.

Why not slam it with O2 and not worry about it? Works for all yeast.

Bobby_M said:

So you don't think cell count has no effect on how quickly they get through the fermentation? I think it's a big factor and it's supported by how quickly a batch will ferment when pitched on a yeast cake or with a large starter.

Do you think my aeration experiment results are false?

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Only if you kept track of everything else. If you want to do science, you have to do it scientifically. Same recipe, same temp, same yeast, same quantity of yeasties, same room, duplicate carboys, just different oxygenations. Try dividing a batch onto 3 carboys, after pitching yeast. One, no nuthin, one shaken vigorously, #3 oxygenated.

I just did a 8 gallon batch, that's what fills my kettle. I divided my starter into the two carboys, on 5'er, the other a 6,5'er. I alternated the output from my cf chiller, and put the two carboy next to each other. One was bubbling in 2 hours, the other took 6. The slow starter finished in about 3 days, the other took 4. So if you think your current batch did something different than the way you think you remmeber some previous batch, I think you have another think coming, ya think?

I was drinking my first batch in 8 days from brewing, summertime, 90 degrees. No oxygenation. But I'm not saying you system is not functional, I'm say niether of us has has proven anything.

Bobby_M said:

Why not slam it with O2 and not worry about it? Works for all yeast.

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100% agree with you.

Why is there like three treads about this right now?

Real simple answer to this. Yeast NEED O2 in order to propagate to the correct level. Give your yeast something to breath off of.

casebrew said:

Only if you kept track of everything else. If you want to do science, you have to do it scientifically. Same recipe, same temp, same yeast, same quantity of yeasties, same room, duplicate carboys, just different oxygenations. Try dividing a batch onto 3 carboys, after pitching yeast. One, no nuthin, one shaken vigorously, #3 oxygenated.
.

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You just described my aeration experiment exactly. Watch the video in my sig.

All is good info. Here is my 2 cents. It would be ideal to put has mush O2 in the wort as you can. The wort will only hold so much. Just like and liquid. I use the O2 bottle to do this and it works very well. The beer seems to start faster and finish quicker and also seems to be more consistane. Remember that 70% of you flavor comes from your yeast, so the happier you make your yeast the better they will work for you. I have brewed a 10 gal batch and split it between two carboys and used the O2 bottle on one and shuch the hell out of the other. The O2 one fermented faster and also had a cleaner taste. Take that for what it is worth, the best way to do it is what works best for you.

Good info on oxygenation levels at brew-monkey.
Here is a link



http://www.brew-monkey.com/brewschool/oxygenation.php

Bobby_M said:

The million dollar question is how much O2 do they really need?

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Well, the maximum saturation of dissolved oxygen water at room temperature is rougly 10%. Any more than that will come out of the wort when you stop aerating.