Not enough oxygen, how do you know?

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DarkUncle

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Just a question here as I was reading Palmer's book. How would one know if the wort did not have enough oxygen in it when the yeast was pitched? And how would this affect the final taste of a beer?

My fermentation started up within 12 hours but pretty much died down to nothing after 3 or so days. May have bubbled a little here and there but I did not want to leave the fridge door open too long and warm up my fermentation chamber to find out. Just wondering if perhaps the oxygen may have been depleted early on because of not having enough in the first place. And if so, what will that do to the taste of my beer?

Oh, and it looks like I definitely had some suck back of the airlock. My Grey Goose level went down to half of where it had been in the airlock. (Yeah I know but I didn't have any cheap vodka laying around at the time :D) Is some suck back normal or perhaps a sign of something?
 
1: If it's in a refrigerator, it's not at optimum fermentation temperature, unless you are lagering.

2: When you boil the wort, you cook 99.999% of all oxygen out of it. If you then cool it down and pitch directly, there really isn't any oxygen at all, and no test is needed. You can count on having zero oxygen. But unless you have a high gravity brew, it should still ferment but have some off-flavors from the yeast being deficient in O2.

#1 is probably your issue.
 
Sorry, should have been more clear. I have it in the refridgerator with a temperature controller. It's been a steady 65.5 degrees in there without much deviation at all.

I boiled 3 gallons, chilled in an ice bath then poured into my fermenter bucket with another 2.5 gallons of bottled water to get it to the 5 gallon total. I did not, however, pour it back and forth a few times though.
 
Relax, you are nervous noobing and overthinking/worrying about stuff.

Just becasue your airlock is or isn't bubbling really doesn't show how active fermentation is. Fermentation ALWAYS starts out active and busy, and winds down after a few days (because most of the sugars get consumed in the early part of fermentation.) But that doesn't mean fermentation is done. The yeast will still swim around and eat any more sugars, ten eventullay start cleaning up after itself.

New brewers allways seem to not get this simple fact, and start getting nervous when stuff slows down. And think something's wrong when it really isnt. It is just that the yeasts are having less sugar to convert...

As to how much oxygen in this batch and if you'll have a problem, stop worrying about that. Just like everything else in brewing you'll find that different brewers will do things differently and still their beer will turn out fine. It tends to happen despite ourselves.

Just about every first time brewer's batch doesn't have enough oxygen, because the brewer traditionally doesn't find out about that (or 1,000 other better brewing tips) until AFTER their first batch is pitched, and they stumblie into a place like this, or discover Palmers Book....and guess what???

Their beer still manages to turn out fine. :) Yours will too. Beers are pretty hardy, despite what you may think.

Don't worry about this batch, figure out how you will get oxygen into future batches. Think about it as insurance for your beers- though it is unlikely you'll have issues if you don't (especially for normal grav beers) you'll up the odds of your beer turning out in the future with proper o2.

If you leave this batch alone in primary for a month, or at least 2 weeks before secondarying if you choose that route, IF YOU HAD ANY OFF FLAVORS FROM NOT ENOUGH O2 (Doubtful) you will give the yeast time to condition it out. Same with bottle conditioning AFTER. The yeast don't like to make messes, so if you let clean up, they will do you proud.

Suck back is normal as well....so bottom line relax...

This is not brain surgery, nor is your beer like a weak baby...it is really hard to screw things up.

Just keep reading, especially on here, and add to your knowlege base for future batches, but don't sweat if you learn something after the fact, it doesn't gaurentee that not doing something will result in bad beers.....

:mug:
 
Yeah, the beer may very well be just fine. I was more interested in the "what if". What happens to a beer if there is not enough oxygen present? So far from what I read in Palmer's book, he's stated how to get the oxygen in but doesn't really go into consequences of not having enough. What happens to fermentation? What happens to taste?

Thaks Revvy, yeah I am doing the nervous noob dance. But just from a philosophical standpoint I am curious. Only because I think that may be the one weak area of my brew and I would like to be able to recognize the effect if it is present at all.
 
DU, as I said, the yeast may create some off-flavors if it's deficient in nutrients, including O2. However, more specifically, it's an issue with wine and mead, or other very high gravity stuff where the yeast is going to be pushed to it's limit, or beyond. As Revvy said, in a typical beer, it's not as important because the yeast has a pretty simple job.
 
DU, as I said, the yeast may create some off-flavors if it's deficient in nutrients, including O2. However, more specifically, it's an issue with wine and mead, or other very high gravity stuff where the yeast is going to be pushed to it's limit, or beyond. As Revvy said, in a typical beer, it's not as important because the yeast has a pretty simple job.

Well, there are some effects from lack of oxygen in beer. Usually, though, it has to do with yeast reproduction. Yeast need oxygen in their reproductive phase. Once the reproduction phase is over, they begin fermentation which is anaerobic. I think the optimum amount of oxygen is 8 ppm, but the yeast can certainly reproduce with much less.

Some of the effects from a lack of oxygen can be underattenuation, and a hint of phenols from stressed yeast. If your beer always finishes higher than you'd expect, it's possible that it's because of a lack of oxygen. As was mentioned, it's more likely to happen in a higher OG wort. In a "regular" sized wort, you should be ok.
 
So effects would include off flavors and the FG not ending up as low as it should have according to the recipe.

Thanks all!
 
I did the shake the carboy method last week as I do all the time. Strapped on my Ipod, rocked the carboy and when that first song was over, I stopped. About 4 minutes. I went down from 1.062to 1.014 in 6 days. Beer tastes just fine.
 
I feel like oxygenating is a bit over-rated. I mean, I do it, but I just shake for a couple of minutes. I always pitch a well oxygenated starter and a hefty amount of yeast. So for me reproduction phase may not be very necesary since i did that in the starter.
 

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