Forgot to aerate

Hi guys,

First post over on the Beer side here. My dad and I started a Coffee porter stout the other day. It had stopped all signs of fermentation after two weeks so I racked it off to sit for another week before adding the coffee. Well I took a gravity reading and it only calculated out to 3% abv (i'll get my notes on the exact gravity readings soon). It also tasted very sweet with almost no hops. I'm not too worried about the hops flavor as I'm not a big hops guy, but I would like to get more than 3% out of this. The initial start of the fermentation was running rather cold at 60F so my dad put the brew belt on it and kicked it up. Fermentation did really well then just died. I was talking to a friend about this and realized I forgot to aerate (knew I had too much whiskey when making this). I wanted to know the best way to get the fermentation going again. I do have more yeast so I could pull some must and make a starter with it then put it back in. Or is it safe to go ahead and aerate the must now, in the mead world of which I am more familiar with this would be ill advised as it would oxidize the mead. Is this also true for beer? I apologize for the newb questions here. Thanks!

First off, it's wort, not must. Must is wine/mead.

Second, no way should you aerate it now. All that will do is oxygenate the beer after fermentation has started which will lead to oxidation (bad flavors in the beer). You could try getting a champagne yeast and seeing if it will eat some of the sugars left over but without enough oxygen in the wort, it may not. You may just need to suck it up and drink it as is and learn from the mistake.

Oxygen is needed for the first step of fermentation, the lag phase, while the yeast are reproducing and making sure there are enough cells to properly ferment your wort. If you did not aerate initially you didn't have enough yeast to eat all of the sugars.
I would make a starter (maybe with an english ale strain) and add that to your porter at high krausen.

cardinalsfan said:

First off, it's wort, not must. Must is wine/mead.

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This is true.

cardinalsfan said:

Second, no way should you aerate it now.
...
You may just need to suck it up and drink it as is and learn from the mistake.

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These are not necessarily true.


Either make a starter and pitch that, or aerate the beer and pitch a packet pf a dry yeast like SA-04. Don't worry about oxidizing the beer- the yeast you add will use the oxygen to reproduce, just like they would have at the beginning.

Thanks for the replies, and yes my bad, it is wort not must. I told you I was a Mead guy... Ok, I will definately make a starter, we used SA-04 to begin with, of which I have more. I also have Nottingham which I am considering since the temperature is a little lower than optimal.

Also, I have meddled with this in the past on wines and had fine results, but what do you think of an extremely minor lipid addition along with the starter. In case I am getting my terms mixed up again I mean a toothpick that has been dipped in olive oil, make sure there are no large drops left on the tip of the toothpick and then dip that same toothpick into the wort. This is an alternative to oxygen the trouble is that is almost impossible not to add too much as the amount actually needed for the yeast is so minute.

Atek said:

Thanks for the replies, and yes my bad, it is wort not must. I told you I was a Mead guy... Ok, I will definately make a starter, we used SA-04 to begin with, of which I have more. I also have Nottingham which I am considering since the temperature is a little lower than optimal.

Also, I have meddled with this in the past on wines and had fine results, but what do you think of an extremely minor lipid addition along with the starter. In case I am getting my terms mixed up again I mean a toothpick that has been dipped in olive oil, make sure there are no large drops left on the tip of the toothpick and then dip that same toothpick into the wort. This is an alternative to oxygen the trouble is that is almost impossible not to add too much as the amount actually needed for the yeast is so minute.

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With s04, aeration isn't really necessary, and neither is a starter. That isn't your problem with this beer.

The lipid addition works, but you need such a minute amount that you have to be careful!

To fix this beer, don't add the lipid now. But what is the current SG reading? I think the issue for your beer is lack of fermentables (lots of dark crystal malts and extract) and not lack of aeration. What was the recipe, so I can make sure?

I will get that information and post it ASAP, I left at my fathers (where the beer itself is, I didn't want it to feel self conscious in my house full of Meads and Wines).

Ok, HERE is the recipe.

Followed this almost to a T, just forgot to aerate. Also, we used SA-05 not SA-04 (sorry for the mixup). My gravity readings are as follows:

3/10/2012 - O.G. - 1.044 (temperature may not have been room temp during reading, closer to 70-80)

3/25/2012 - S.G. - 1.018

4/6/2012 - S.G. - 1.015

So it looks like its still fermenting albeit VERY slowly. Assuming the O.G. is correct then its max ABV is 6% its current ABV is 4%. I assumed this would have a higher ABV than this but I could be mistaken.

So the question is, do I leave it be until it finishes, do I go ahead and add the coffee and proceed as the recipe suggests, or do I add more yeast to speed up fermentation?

On another note I was really hoping for more alcohol than 6%, would it be possible to fortify with say brandy up to say 9% and still achieve bottle carbonation? If so what would you recommend as the fortifier?

Thank you for all the help here!

80 F would add 2 points to the gravity = 1.046, which is what the recipe says it should be.

I would have expected the beer to get down to around 1.012, so 1.015 is not too bad. At 1.012 you will have about 4.5% alcohol, and that's as good as you can expect. Beer does not ferment to dryness like mead.

You mentioned that it might be in a cool place. This could slow fermentation and stall it before it is finished. Move the beer to somewhere that is about 70 F to finish it off. You might get a point or 2 more.

Not aerating will reduce the amount of yeast produced, which will stress the yeast and could make it stall before it finishes. If you added 'top-up' water, that will have had a lot of O2 in it already, and should be enough for a beer of this gravity.

Adding more yeast at this point will do nothing ..... well, if you made a big starter, and used a higher attenuating yeast, you might get a few points, but that is a lot of work. And champagne yeast will not do anything for you.

I'd move it t0 a warm location for a week and then say it is done.

Yes you can add liquor at bottling if you like. Adding about 1% abv of brandy or bourbon will be very noticeable. More than that will make it harsh, and thin the flavor out. S-05 will be fine for bottle carbonation up to 10% (maybe even higher).

Just leave it alone. I wouldn't even move to warmer temps (70+). Give it another 1-2 weeks.