Forgot to aerate my brew

It just dawned on me two weeks into fermentation. I can definitely tell that it's under attenuating (no air lock activity, smaller krausen and trub than normal).

Any fixes to help finish fermentation?

After two weeks, temperature is probably not as important as it was the first few days (yeast/beer dependent). Try warming it slowly to keep the yeast active as long as possible.

What was the original gravity? What was your grain bill? What yeast did you use? What temp are you fermenting at?

It helps to just kind of know what is up to help you. Your yeast could be done, it could be too warm or too cold, your grain bill will help people to see if the yeast is likely done and knowing what yeast will tell us the preferred temp, whether it flocculates high - low, and the attenuation.

Details = answers, most of the time.

If it's been struggling along for 2 weeks, and you're sure you didn't aerate at all, then the yeast have probably been stressed the whole time and have likely produced a gamut of off-flavours. I'd suggest tasting a sample to decide whether or not the batch is worth finishing. There are certainly tricks to get it to finish fermenting down to FG (aerate now and pitch a fresh batch of active yeast), but that won't fix the off-flavours that have already been produced, and would likely oxidize your beer as well.

I agree with trying to warm it up slowly. Initial fermentation is probably done so I think you'll be ok there.
I forgot to aerate my first couple brews and they were ok. Depending on how you transferred your wort into your fermentor you probably aerated it at least a little bit.

More information will help us answer your question but I wouldn't get stressed about it. I've made quite a few beers that I've made mistakes and they have turned out okay. Not the greatest beers but drinkable...if it was me I'd let it finish in a couple more weeks...bottle it and see how it ends. You may be surprised. IMO

freisste said:

After two weeks, temperature is probably not as important as it was the first few days (yeast/beer dependent). Try warming it slowly to keep the yeast active as long as possible.

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Good idea. I'm fermenting US-04 at 60f, so I have a little latitude in temp right now.

How do you know it is underattenuating? The airlock activity and size of the krausen don't really tell you that. Have you taken any gravity readings? Can you post your OG, FG, and recipe?

Also, 60 is on the cool side for 04 once the initial vigorous fermentation slows down. I usually ferment at around 62-64 for the first few days, then bump it up to 66-67 to finish. Once it slows down, it has a tendency to drop like a rock.

Hello said:

What was the original gravity? What was your grain bill? What yeast did you use? What temp are you fermenting at?

It helps to just kind of know what is up to help you. Your yeast could be done, it could be too warm or too cold, your grain bill will help people to see if the yeast is likely done and knowing what yeast will tell us the preferred temp, whether it flocculates high - low, and the attenuation.

Details = answers, most of the time.

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See screenshot for grain bill. I'm using US-04 and fermenting at 60f. My LHBS was out of american ale yeasts, so I had little choice on my yeast selection.

Thanks for your help! Its a noticeable difference from other times I've used this yeast.

You did not really use 10 lbs of carapils, did you?

Please tell me there's a typo in that grainbill. Did you seriously use Carapils for 76% of your grainbill? That's supposed to be the Pale Ale malt. Carapils is largely unfermentable. That would definitely explain why your fermentation is stalling out. It's consumed all the fermentables, and you're left with a ton of unfermentable sugars. I'm afraid it's done.

With that grain bill, it's probably done. S-04 is a great yeast but it's not going to eat through malt that was basically already converted most of the way, which is that carapils. Did your LHBS see your grain bill? If so, they could have done you a solid and told you carapils isn't a base malt.

As kombat says, it is done.

For future reference, you can read about grains and see the recommended max % that you should have in a recipe. I like that beersmith tells me this when I review the properties of the grain. Knowing the limits helps you maximize fermentables.

Now you can see why knowing the yeast, temp, and grain bill helps getting you answers.

lol that has to be a typo.

^ I'd think so but he is screen shot his recipe via his brewing app. My hope is that he did enter that but actually bought pilsner.

kombat said:

Please tell me there's a typo in that grainbill. Did you seriously use Carapils for 76% of your grainbill? That's supposed to be the Pale Ale malt. Carapils is largely unfermentable. That would definitely explain why your fermentation is stalling out. It's consumed all the fermentables, and you're left with a ton of unfermentable sugars. I'm afraid it's done.

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Lol. Yep. Its a typo.

Okay so was your OG 1.068? Or what was it? What is the gravity now?
Between the two, using S-04 with a attenuation of about 75%, maybe it is done. Pony up those two numbers and we can tell you if it is done.

Hello said:

Okay so was your OG 1.068? Or what was it? What is the gravity now?
Between the two, using S-04 with a attenuation of about 75%, maybe it is done. Pony up those two numbers and we can tell you if it is done.

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+100! Gravity will tell the story here. The correct grain bill would help, too.

boydster said:

+100! Gravity will tell the story here. The correct grain bill would help, too.

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Right on! The OG was 1.068.

I realize I have not provided a current gravity reading as I have not taken one yet. I also know that I may be speculating that there may be a problem. Too much thinking happens when you have an hour commute.

HillWilly said:

It just dawned on me two weeks into fermentation. I can definitely tell that it's under attenuating (no air lock activity, smaller krausen and trub than normal).

Any fixes to help finish fermentation?

Click to expand...

HillWilly said:

Right on! The OG was 1.068.

I realize I have not provided a current gravity reading as I have not taken one yet. I also know that I may be speculating that there may be a problem. Too much thinking happens when you have an hour commute.

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As boydster said there's no way you can know if it's underattenuating based on these observations. A gravity reading is the only way to know where it's at.

Also, aerating is a lot less critical with dry yeast because they already have a good supply of sterols (which is what the yeast use oxygen to make) built into their cell walls from the manufacturer. So I wouldn't worry about it too much.

I never aerate with dry yeast. Your failure to aerate won't be a problem with S-04. There are those who will dispute this. Ignore them. Take comfort from the fact that yeast need oxygen to produce lipids for the construction of permeable cell walls and dry yeast producers optimize lipid levels in their preparations. You're fine.

HillWilly said:

Right on! The OG was 1.068.

I realize I have not provided a current gravity reading as I have not taken one yet. I also know that I may be speculating that there may be a problem. Too much thinking happens when you have an hour commute.

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Honestly then, we're all just running in circles here without a reading. We can speculate all day long why you think you have a stalled fermentation but the fact is, you probably don't because there is nothing to tell us that there is a problem. The only thing we can do is remind you that carapils isn't a base grain but since you did say it was a typo, I assume there's little else we can do right now. When you get home just take a reading.

Also, I just removed the carapils and entered in pilsner malt instead. I don't see the point of the 2-row in there but that has nothing to do with anything here. Beersmith gave me 1.068. I assume you can expect final gravity around 1.010 to maybe up to 1.016, give or take. Maybe even 1.020 I suppose but S-04 is a beast. I suspect more than 75% attenuation based on the grain bill even without aeration.

Next hour-long commute, think about what you want to brew next instead.