successfully jumpstarting a stuck fermentation with pure O2

[dmarc85]

So here's my predicament: I brewed a 15gallon batch of super-dry imperial porter (almost half the fermentables is dextrose). The OG was 1.088, but it knocked off about 1.042 for nearly a week. During that time I added WLP099 on top of my first strain of 007. From the get-go, I used the relative dose spec of yeast nutrient, since I knew my schedule of fermentables would leave my beer with insufficient nitrogen levels.

After a few days after adding a huge starter of 099 with light stirring, I saw absolutely zero change in gravity so I called into question sufficient levels of oxygen. I had not added pure oxygen to my wort prior to pitching, because I wanted to see if the falling effect that occurred when my worth entered the top of my conical would adequately mix in enough oxygen.

I surmise that that my shoot-from-the-hip aeration method was inadequate. I know that my readings were accurate since my refractometer is reading 1.000 with 60F distilled water.



Although all I've read online says never to aerate after fermentation, I am at a loss of ideas. I kicked up the yeast cake and gave my wort a blast of pure oxygen (20 secs) and I've been watching it over the last few hours. I heated my ferm chamber to 80 just to stimulate production for a couple hours.

I'm noticing a small bubbles starting to rapidly break the surface and I'm noticing the first signs of a krausen starting to form on the top.

My last gravity reading was 1.037-ish andI get a 'blub' in my airlock hose every 10 secs. At this point I'm fairly confident that fermentation is going to kick back up again in the next few hours. I'll leave updates.



The true test will be when I taste the finished product and if I notice signs of oxidation.

 

[stpug]

You seem to be on top of your game with the exception that you are not correcting for your refractometer reading in the presence of alcohol. O2 should not be added after about 24 hours of fermentation, but maybe it's not a huge detriment - we'll see.

1.088 down to ~9.2 brix is....

 

[dmarc85]

You seem to be on top of your game with the exception that you are not correcting for your refractometer reading in the presence of alcohol

ahh, good point. This is my first time using a refractometer and it seem I have overlooked that detail Ill do some research on this.

 

[stpug]

1.005 ± 3 points (1.002-1.008ish) is your final gravity range. You should double-check your FG with a hydrometer to feel more confident.

 

[trentm]

I'll be interested in the results. My gut says you'll be OK because the yeast are still active and should quickly use up the O2. I have heard of people adding O2 much after the 24 hour recommendation in big beers. However, this is a bit further than I have heard of. Keep us posted.

 

[dmarc85]

I sure will. I actually just used the brix calculator on NWB's website and according that my beer's done. 1.005. Yikes, now I'm afraid that I just oxidized my brew! I'm hoping that my observations of fermentation are actually fermentation. Hopefully all that O2 gets gobbled up and then I can cold crash it.

 

[Hello]

I sure will. I actually just used the brix calculator on NWB's website and according that my beer's done. 1.005. Yikes, now I'm afraid that I just oxidized my brew! I'm hoping that my observations of fermentation are actually fermentation. Hopefully all that O2 gets gobbled up and then I can cold crash it.

I would definitely use a hydrometer at this point to check. It is possible it is still done though.

 

[dmarc85]

Well there is definitely fermentation happening since my airlock bubbles have sped up and the krausen is building...

Maybe my OG reading was wrong, but my instincts about the oxygen content were luckily accurate. Haha.


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[dmarc85]

I just need to find my test cylinder to get a hydrometer reading.


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[turkeygecko]

Out of all the $ I've spent on equipment, I think I regret the refractometer purchase the most. It sits in its case, and the hydrometer gets used all the time.

 

[donk5]

I love my refractometer. Easy, quick, and hardly uses any wort. Quickly replaced my hydrometer.

 

[number40fan]

@turkeygecko, I'll give you $15, shipped for it.

 

[stpug]

I'm also a refractometer fan. As long as you know it's quirks and limitation, it's indispensable. After correction, I've found mine to generally be within about a point of the hydrometer FG which makes it totally useful for the full brewing process (and within my margin of error on reading a hydrometer).

 

[doug293cz]

I'm also a refractometer fan. As long as you know it's quirks and limitation, it's indispensable. After correction, I've found mine to generally be within about a point of the hydrometer FG which makes it totally useful for the full brewing process (and within my margin of error on reading a hydrometer).

Agree totally.

Brew on

 

[acidrain]

Out of all the $ I've spent on equipment, I think I regret the refractometer purchase the most. It sits in its case, and the hydrometer gets used all the time.

You measure hot wort/second runnings, etc with a hydrometer? Why?

 

[balrog]

I'm also a refractometer fan. As long as you know it's quirks and limitation, it's indispensable. After correction, I've found mine to generally be within about a point of the hydrometer FG which makes it totally useful for the full brewing process (and within my margin of error on reading a hydrometer).

I'm still a neophyte but have determined that refractometer will be quicker data pre-ferment, and I'm hoping close enough post-ferment data to make the expense worth it. And mine just arrived in the mail today, I can hardly wait to try it out. And with all the friggin hydrometers I've broken in just one year of brewing, I'm hoping the refractometer is sturdier.

 

[b-boy]

The only issue I've encountered with my refractometer is using it in extremely cold weather (5F-10F). It pretty much freaks out. Other than that it's great.

 

[1van]

It has become a very valuable tool for me on brew day, helps me hit all my numbers just right. I just don't use it after the yeast is pitched....hydrometer for that. I hear there is some math that I can do to use the refractometer, but I AM that lazy

 

[dmarc85]

Update: I'm getting bubbles every 4 seconds. Definitely active ferm going on. The only bad news is that I have absolutely no idea how much alcohol is going to be in my beer because I'm pretty sure my first reading was bad. I'll get back to everyone on the flavor as soon as I have a taste.



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[turkeygecko]

@turkeygecko, I'll give you $15, shipped for it.

Gotta keep it around for the day I break my hydrometer... which will happen. I'm probably on my third already.

 

[turkeygecko]

You measure hot wort/second runnings, etc with a hydrometer? Why?

Not sure if you are asking: 1. why I measure the gravity of these things at all? Or, 2. why I choose to use the hydrometer instead of the refractometer?

1. I always take post-mash/pre-boil gravity readings so I can monitor my conversion efficiency and kettle efficiency. Have to know these to know your system and size recipes accordingly.

2. I can take 4 oz. of wort in a glass, and take 5 readings on the refrac (using 5 different drops of wort from the same sample) and get very different readings. There's no guesswork with a calibrated hydrometer.

 

[b-boy]

I can take 4 oz. of wort in a glass, and take 5 readings on the refrac (using 5 different drops of wort from the same sample) and get very different readings. There's no guesswork with a calibrated hydrometer.

This makes no sense. I can see if you take readings from the bottom and top of a pot after sparging, but if you are seeing that in a small sample I'd say your refractometer is screwed up.

 

[turkeygecko]

This makes no sense. I can see if you take readings from the bottom and top of a pot after sparging, but if you are seeing that in a small sample I'd say your refractometer is screwed up.

I don't really know what to tell you. Three guys in my brew club have the same issue. I suppose we could all have the same refrac. We all live in Saint Paul, MN and bought from same retail location. But, judging from the OP's picture, same exact model.

 

[doug293cz]

I don't really know what to tell you. Three guys in my brew club have the same issue. I suppose we could all have the same refrac. We all live in Saint Paul, MN and bought from same retail location. But, judging from the OP's picture, same exact model.

Pretty much every refractometer picture I have seen looks exactly the same. Can't tell mfg or model from a pic.

Do you get repeatable readings with DI/RO/distilled water? Do you completely cover the sample area, and make sure there are no bubbles? Do you squeeze extra sample out from between the cover plate and the sample area? Do you rinse and dry between samples? Do you make sure that your sample dropper doesn't have any water or other wort traces in it prior to taking the sample? With the small samples involved, you need to make sure you are getting a "pure" sample.

Brew on

 

[mvcorliss]

Pretty much every refractometer picture I have seen looks exactly the same. Can't tell mfg or model from a pic.



Do you get repeatable readings with DI/RO/distilled water? Do you completely cover the sample area, and make sure there are no bubbles? Do you squeeze extra sample out from between the cover plate and the sample area? Do you rinse and dry between samples? Do you make sure that your sample dropper doesn't have any water or other wort traces in it prior to taking the sample? With the small samples involved, you need to make sure you are getting a "pure" sample.



Brew on

And are you making sure your sample temp is close to 68f, and are you calibrating at that temp also?


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[doug293cz]

And are you making sure your sample temp is close to 68f, and are you calibrating at that temp also?

Unlike hydrometers, sample temp isn't usually an issue with refractometers. Almost all refractometers have automatic temperature compensation, and the sample sizes are so small that the sample temp equilibrates with the instrument very quickly. You would have a hard time getting a reading before the sample cooled adequately, but give it 10 - 15 seconds just to be safe.

Brew on

 

[mvcorliss]

I read up on temp correction in refract and wasn't very impressed. They still need to be calibrated at the correct temp and the sample needs to be at least close to that temp. Wide variations in temp will still introduce errors.
Also keep mind if you are brewing in very high or very low ambient temps and your refractometer is sitting out at those temps, that tiny volume of sample sitting for the required 20 or 30 seconds on the plate is only going get close to the temp of the plate be it 85f or 40f. Your temperature correcting refractometer is not going to be as accurate as it could be.


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[b-boy]

Also keep mind if you are brewing in very high or very low ambient temps and your refractometer is sitting out at those temps, that tiny volume of sample sitting for the required 20 or 30 seconds on the plate is only going get close to the temp of the plate be it 85f or 40f. Your temperature correcting refractometer is not going to be as accurate as it could be.

This is very true. I have issues in cold temps. I just go inside and take a reading.

 

[balrog]

How long to wait inside before you get good readings?


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[turkeygecko]

Pretty much every refractometer picture I have seen looks exactly the same. Can't tell mfg or model from a pic.



Do you get repeatable readings with DI/RO/distilled water? Do you completely cover the sample area, and make sure there are no bubbles? Do you squeeze extra sample out from between the cover plate and the sample area? Do you rinse and dry between samples? Do you make sure that your sample dropper doesn't have any water or other wort traces in it prior to taking the sample? With the small samples involved, you need to make sure you are getting a "pure" sample.



Brew on

I have calibrated with distilled water. I do cover sample area. To be honest, not sure if I rinse and dry between samples. Dropper is definitely dry. But, the reason people use refracts is that it is supposed to be easy and fast. If I'm going to run down a checklist of things to do before shooting a sample, doesn't the benefit seem lost?

Other than saving volume, whats a refract do for you that a hydrometer cannot? For those that say they get a very fast reading, can you honestly day you shot multiple samples to confirm consistency?

Listen, if they work for you guys, more power to ya, I've just found they are not reliable. I'd rather brew a quart more wort and remove the guesswork.

Cheers,
Drew


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[turkeygecko]

Duplicate post

 

[doug293cz]

I have calibrated with distilled water. I do cover sample area. To be honest, not sure if I rinse and dry between samples. Dropper is definitely dry. But, the reason people use refracts is that it is supposed to be easy and fast. If I'm going to run down a checklist of things to do before shooting a sample, doesn't the benefit seem lost?

Other than saving volume, whats a refract do for you that a hydrometer cannot? For those that say they get a very fast reading, can you honestly day you shot multiple samples to confirm consistency?

Listen, if they work for you guys, more power to ya, I've just found they are not reliable. I'd rather brew a quart more wort and remove the guesswork.
/QUOTE]

When I have taken multiple readings, the results have been extremely consistent. When dealing with hot wort it's way faster than waiting for a cup or so of wort to cool for a hydrometer reading. Proper sampling technique becomes a habit pretty quickly, just like proper sanitizing procedures. And the biggest draw for me is the small sample size.

Brew on

 

[turkeygecko]

/QUOTE]



When I have taken multiple readings, the results have been extremely consistent. When dealing with hot wort it's way faster than waiting for a cup or so of wort to cool for a hydrometer reading. Proper sampling technique becomes a habit pretty quickly, just like proper sanitizing procedures. And the biggest draw for me is the small sample size.



Brew on [/QUOTE]


I don't wait for the wort to cool with hydrometer. I have a thermapen and temp correct reading. Like I said, no problem brewing an extra quart of wort.

But, glad the refract works well for you. Happy to swap refracts with you if you're hell bent on convincing me I should use a refract!


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[balrog]

I've only used hydrometer to this point, a year into brewing; I find them difficult--not for temp corrxn, rather for ease of reading because of bubbles around meniscus or CO2 bubbles in solution or adhering to the side or the infuriating way that the one scale I want to read always rotates around to the dark side of the moon. Rather than buying an expanded range hyrdrometer to more easily read the scale, I am going to try a refract.

Which begs the question: will having bubbles in solution, as happens with 3-4 wk primary fermentation sometimes (just the way I do it), make a difference when taking readings with refract, knowing there will be the whole question of alcohol adjustment?

 

[stpug]

I don't wait for the wort to cool with hydrometer. I have a thermapen and temp correct reading. Like I said, no problem brewing an extra quart of wort.

Above about 90°F, temp correction becomes unreliable for hydrometers. You really should be cooling those samples a bit before taking a reading. It's probably as simple as pouring your sample into a frozen coffee mug prior to putting in your hydro tube/flask. Just knock down the extreme high temps quickly, and temp correct for the rest.

Refracts have a similar issue: Once the crystal gets too warm it will start giving inaccurate and inconsistent readings. I find myself doing the same thing for refracts as you need to for hydros, cool the sample a bit before putting on the crystal. I put my sample in a cool shot glass, and then pour a small amount onto a spoon which I use to dribble on the crystal. By the time the sample is hitting the crystal it's luke warm, and the crystal can compensate for that temperature variance.

 

[stpug]

Which begs the question: will having bubbles in solution, as happens with 3-4 wk primary fermentation sometimes (just the way I do it), make a difference when taking readings with refract, knowing there will be the whole question of alcohol adjustment?

Do your best to keep bubbles from getting trapped between the crystal and cover plate. It's pretty easy to "drag" one off of the crystal with a spoon. However, I rarely get a bubble stuck on the crystal when taking FG readings from my fermenter. Just figure out the method that works best for you and roll with it.

 

[Owly055]

Out of all the $ I've spent on equipment, I think I regret the refractometer purchase the most. It sits in its case, and the hydrometer gets used all the time.

Why? For me it's just the opposite. The hydrometer sits in the cupboard, and the refractometer is used exclusively. Once you get onto the correction, it's effortless.


H.W.

 

[doug293cz]

Happy to swap refracts with you if you're hell bent on convincing me I should use a refract!

Not trying to convince you of anything. Just trying to present a balanced picture of refractometer usability. You made statements that refracts were unreliable based on your experience, and I countered with statements based on my experience that I did not find them unreliable. Both hydros and refracts can work well if used properly, and both require adherence to correct practices for good results. Neither one is zero effort. Your preference is your preference, and mine is mine. Neither is wrong.

Brew on

 

[peterj]

I agree with turkeygecko about refractometers. I've tried on a few different brews to compare a refract reading to a hydrometer and the refract was always off, and I don't think it was a consistent number off that I could just correct for. I know they work great for some people, but for me there's just no benefit.

I've also found that if I get a small amount of hot wort in a spoon and allow it to cool a little (like 15-30 seconds) to get a more accurate reading with the refractometer, it ends up reading way too high because the hot wort is still evaporating water while it's cooling in the spoon. Anyway, it doesn't take long at all to cool 4 oz of hot wort in a Tupperware container full of ice water. Like maybe 5 minutes while I'm waiting for the wort to come to a boil.

When I first got the refract I was using it but I was always double checking with a hydrometer sample, so I finally just said "screw it". I only usually take 3 hydrometer samples over the course of a brew anyway (pre-boil, post-boil, and pre-packaging) and the pre-boil one I can put back in. Sometimes I won't even take a post boil, I'll just calculate it from the pre-boil and the boil off. And I know it's brewing dogma to take 2 readings 2-3 days apart before packaging, but if the fermentation looked normal, it's been 2-3 weeks, and I'm in the right range then I pretty much know it's done.

 

[Roadie]

Wow, this thread has quickly turned into the refractometer debate forum!

OP please post your findings as I didn't think it was ok to add additional oxygen to the partially fermented beer once you were past 24 hours or so as it would oxidize the beer. I've heard of adding some sugar and gently stirring the wort/beer beyond 24 hours to arouse the yeast but never adding more oxygen.