Measuring Dissolved Oxygen....

[r8rphan]

Is there an affordable way to measure dissolved oxygen?

The meters are expensive.. I have seen 'test kits' for use with aquariums..

Will they work for brewing to see if there is enough oxygen in the wort?

If so, will they work on the wort itself, or do they have to be used on pure water to see what is needed, and then just duplicate the settings used on wort?

This is the kind of O2 TEST KIT I am referring to....

 

[Sourz4life]

The kits are can be pretty off. Any dissolved oxygen meter that works properly is most likely 120$+.

 

[r8rphan]

The kits are can be pretty off. Any dissolved oxygen meter that works properly is most likely 120$+.

I have been experiencing incomplete ferments.. Now that I have a means to easily take samples, and can see that that is what is happening, I need to find out how to fix it...

Seeing as the beer tastes the same as was happening with the old system, this is a problem that is definitely occurring on the fermentation side of things...

I'm getting complete conversion (iodine test), efficiency off the charts (88% measured with refractometer), but incomplete fermentation (.065 OG finishing at around .030, way short, measured with both refractometer/calculator and hydrometer, with matching results)

So, seeing as there are only three components to a successful ferment.. Sugars, temperature, and oxygen... It has to be one of those three things causing the problem...

I pitched two packets of US 05 into a 10 gallon batch at 66 degrees... Once it stalled, I tried shaking it some, upping the temp, etc.. no restart.. I then made a starter out of four more packets, and pitched that.. 'no effect'.... So, I'm thinking there wasn't enough oxygen in the wort to complete fermentation... It's the only thing I could not measure...

The fermentation chamber keeps everything pretty dang stable (verified by the fermometer strip on the Speidel), and I can't believe that I've been having 'unfermentables' problems over many many brews, with two completely different breweries.... This new brewery even involves the use of RO filter and building up the water profile from scratch...... So it has to be the oxygen..

Dumping the air stone in the kettle prior to transfer method, and going with pure oxygen being injected right as it goes into the fermenter... But don't know how to measure if i'm injecting enough or too much....

Ideas?

 

[EarthwormJim]

Are you using the same thermometers in the new system? Many tales on here of people finding that there thermometers are way off, some by more than 10 degrees. Would seem a stretch that it would effect the attenuation that much, but it may contribute.

If you could post your recipe it may help give people some ideas.

 

[jcav]

Try using Wyeast yeast nutrient in the last few minutes of the boil. It is one of the few nutrient mixes on the market that has zinc in it. Zinc is the key ingredient that the yeast need for yeast heath, in order to multiply and do their thing. Also I make starters with liquid yeast packs not dry, so you may want to try that next time also. Give that Wyeast nutrient a try on your next batch, I think you will see a big difference. I always use it on every single batch I make. Just my two cents.....

John

 

[maierhof]

I have to say that this seems weird for sure - .030 and that is it?

It is very hard to have too much oxygen in your pre-fermenting brew.
How long are you running your oxygen for? Or is it Inline with your setup?

Lame thought but Perhaps you are not getting your stone as clean as you thought?
Have you boiled that sucker yet?

What temp do you push your 02 at?

What is your setup - let's see it or describe it for us to let us help you.

 

[Sourz4life]

So this can range from set up to set up of course, but if you ran it inline for instance and ran it for half of the transfer from kettle to fermenter you should be at about 8 PPM. The same can be said if you were to put it in the fermenter directly into the wort and blast it for about 70 seconds. Again this is kind of a rough estimate but a good starting point to tweak from if you don't have a DO meter.

 

[r8rphan]

Are you using the same thermometers in the new system? Many tales on here of people finding that there thermometers are way off, some by more than 10 degrees. Would seem a stretch that it would effect the attenuation that much, but it may contribute.

If you could post your recipe it may help give people some ideas.

No.. Old system I used a floating glass thermometer for mash, as well as a dial thermometer on the keggle.. I double checked both with a digital meat thermometer...

New system I am using a probe and EZ Boil controller (old system propane, new system electric)

I am using the same fermentation chamber, that uses a digital temp controller (the kind you get off of ebay for 20 bucks).. In the previous set up, I had two glass carboys (each with a fermometer stuck on them), and the temp probe for the controller was taped to a glass jar of water that sat inbetween and in contact with the carboys.. All three read the same..

In the new setup, I am using the same fermentation chamber, and the same controller, with the controller probe stuck in a stainless steel thermowell in the top of a new 60L speidel fermenter... The speidel has a brand new fermometer stuck to it, horizonally at about the 9 gallon mark.. Both confirm each other....

Here's the recipe.. Just a basic American IPA...

 

[r8rphan]

Try using Wyeast yeast nutrient in the last few minutes of the boil. It is one of the few nutrient mixes on the market that has zinc in it. Zinc is the key ingredient that the yeast need for yeast heath, in order to multiply and do their thing. Also I make starters with liquid yeast packs not dry, so you may want to try that next time also. Give that Wyeast nutrient a try on your next batch, I think you will see a big difference. I always use it on every single batch I make. Just my two cents.....

John

How much do I add?

I'm going to try US 04 on the next one (might use more than 2 packets this time though)... If that doesn't work, I guess I'll buy a stir plate and try making a starter from liquid yeast.... I already have the 2000ml flask, airlock, and stir magnet...

 

[r8rphan]

I have to say that this seems weird for sure - .030 and that is it?

It is very hard to have too much oxygen in your pre-fermenting brew.
How long are you running your oxygen for? Or is it Inline with your setup?

Lame thought but Perhaps you are not getting your stone as clean as you thought?
Have you boiled that sucker yet?

What temp do you push your 02 at?

What is your setup - let's see it or describe it for us to let us help you.

I have not used pure oxygen yet.. I was using an air stone with an aquarium pump and regular air for a few minutes during chilling... Once the temp dropped below 120, I put the air stone in the wort, and left it in there for a few minutes past when the system reached pitching temp (turned off chill water and just let the pump recirculate the wort through the CFC while the air pump ran)... Then I transferred (pumping through about 35-40' of 1/2" tubing to the fermenter)

I am right now putting an O2 system together.. I have the regulator and the oxygen, most of the fittings, just need to pick up a couple more fittings and an thread in air stone... I plan to inject it, at pitching temp, about a foot before the fermenter, planning on filling the fermenter from the bottom up this time since I won't need the added splash of pumping it in the top...

I was hoping to be able to do a dry run with O2 in water at temp, and measure it, so i could know if I had the right amount of oxygen... Everything I'm reading is that it's pretty much impossible to over oxygenate with regular air via an aquarium pump (like I was doing before), but easy to do so with pure O2, which can cause the beer to become oxidized.. This is why I wanted to measure it..

HERE IS MY SETUP (Page 11 and 12) give a good overview

Would being too close to the cooling coils of the freezer cause any issues? I was wondering if I should put a layer of 1/2" foam board between the coils and the fermenter or something...

 

[jcav]

How much do I add?

I'm going to try US 04 on the next one (might use more than 2 packets this time though)... If that doesn't work, I guess I'll buy a stir plate and try making a starter from liquid yeast.... I already have the 2000ml flask, airlock, and stir magnet...

Add 1/2 teaspoon (2.2 grams) per 5 gallons of wort. Hope this helps!

John

 

[r8rphan]

Add 1/2 teaspoon (2.2 grams) per 5 gallons of wort. Hope this helps!

John

Is THIS the Stuff?

 

[jcav]

Is THIS the Stuff?

Yes sir!

 

[EarthwormJim]

Are you firing your element during the mash? I wonder if there might not be some localized overheating denaturing some of the enzymes. I think the alpha enzymes denature at lower temps and they are the ones that break down the longer chain sugars and make the wort more fermentable.

You could run a fast ferment test on some of the wort next time you brew. Just pull off about a quart and basically make a starter. Pitch more yeast to it than needed, maybe a quarter packet, keep it around 70, aerate it continuously and let it ferment out. Should only take a couple days. Normally you would throw it on a stir plate but If I read correctly you dont have one. I would just pump air into it for a couple days and give it a swirl when you walk by. Given the conditions, the yeast should eat everthing that is fermentable in the test wort and stop at their attenuation level in the fermentor. If the test ferments completely but the fermentor finishes high, you know O2 or maybe the fermentor being near the cooling coils could be a problem. If the test also finishes high, you know the wort isn't as fermentable as expected so something went wrong in the mash. With the numbers you posted, if the problem was the fermentability, the test would have stopped around 1.018, if the problem was in the fermenter, the test would probably have gotten under 1.010.

 

[philipCT]

It seems you've changed up almost everything except your yeast regimen.

Without doing any more head-scratching, I would second the suggestion to try using a liquid smack pak of Wyeast 1056 on your next brew. Use the Brewer's Friend Yeast pitch rate calculator and make a sufficiently large starter. I do this for every brew and have *never* had a stalled fermentation. Even the one time I pitched into a big imperial stout that I had completely forgotten to aerate.

If your fermentation temperature control is good - and it looks like it is - I guarantee you'll like the results.

You're welcome.

 

[maierhof]

I have not used pure oxygen yet.. I was using an air stone with an aquarium pump and regular air for a few minutes during chilling... Once the temp dropped below 120, I put the air stone in the wort, and left it in there for a few minutes past when the system reached pitching temp (turned off chill water and just let the pump recirculate the wort through the CFC while the air pump ran)... Then I transferred (pumping through about 35-40' of 1/2" tubing to the fermenter)

IMO - This could be it. Three things to note here:
1 - I am a fan of using pure oxygen. I use the small red bottles found at HD, the small brass regulator from morebeer, and a ss wand with detachable stone. I burst it into the fermentor in 15-20 second batches with a 3-5 second wait time in between for a total of about 1.2 - 1.5 minutes of total o2 push time (for a 10 gallon batch btw).
2 - each time I transfer from keg to keg (via a jump line of about 6ft btw) I lose some pressure. 35-40 feet transfers are going to take more o2 or co2 out of that line that you think...
3 - Temp is everything for co2 or o2 absorption - anything over 80*F is just pissing in the wind IMHO because the majority of it is just not going to stay in suspension...

SO... I think with the air pump, the long transfer and the higher temp being where it was you were just not getting the optimal amount of O2 into that beer when it needs it.

I am right now putting an O2 system together.. I have the regulator and the oxygen, most of the fittings, just need to pick up a couple more fittings and an thread in air stone... I plan to inject it, at pitching temp, about a foot before the fermenter, planning on filling the fermenter from the bottom up this time since I won't need the added splash of pumping it in the top...

I was hoping to be able to do a dry run with O2 in water at temp, and measure it, so i could know if I had the right amount of oxygen... Everything I'm reading is that it's pretty much impossible to over oxygenate with regular air via an aquarium pump (like I was doing before), but easy to do so with pure O2, which can cause the beer to become oxidized.. This is why I wanted to measure it..

Beautiful - that sounds great - let us know how this new process works!
IMHO - this should solve your issue.

Would being too close to the cooling coils of the freezer cause any issues? I was wondering if I should put a layer of 1/2" foam board between the coils and the fermenter or something...

I think you are fine the way it looks now - a nice even push of cold onto the plastic fermentor and a heater on the other side lower. It looks like a frankestein inside that thing but it does the job well - so who cares what it looks like, right?

 

[55x11]

I have been experiencing incomplete ferments.. Now that I have a means to easily take samples, and can see that that is what is happening, I need to find out how to fix it...

Seeing as the beer tastes the same as was happening with the old system, this is a problem that is definitely occurring on the fermentation side of things...

I'm getting complete conversion (iodine test), efficiency off the charts (88% measured with refractometer), but incomplete fermentation (.065 OG finishing at around .030, way short, measured with both refractometer/calculator and hydrometer, with matching results)

So, seeing as there are only three components to a successful ferment.. Sugars, temperature, and oxygen... It has to be one of those three things causing the problem...

I pitched two packets of US 05 into a 10 gallon batch at 66 degrees... Once it stalled, I tried shaking it some, upping the temp, etc.. no restart.. I then made a starter out of four more packets, and pitched that.. 'no effect'.... So, I'm thinking there wasn't enough oxygen in the wort to complete fermentation... It's the only thing I could not measure...

The fermentation chamber keeps everything pretty dang stable (verified by the fermometer strip on the Speidel), and I can't believe that I've been having 'unfermentables' problems over many many brews, with two completely different breweries.... This new brewery even involves the use of RO filter and building up the water profile from scratch...... So it has to be the oxygen..

Dumping the air stone in the kettle prior to transfer method, and going with pure oxygen being injected right as it goes into the fermenter... But don't know how to measure if i'm injecting enough or too much....

Ideas?

My opinion - your stalled fermentation has (almost) NOTHING to do with oxygenation. I wouldn't get DO meter just to nail this down.

Yeast health - how "fresh" is your yeast? do you make a starter? Do you pitch yeast nutrients?
Have you tried forced fermentation on part of your wort? Krausening?

Mash - is it possible you mash too high? I sort of doubt it myself, as 1.030 is way too high for this.

Temperature - is temperature too low for fermentation?

I would definitely try forced fermentation, perhaps pick a new, well-attenuating yeast.

Oxygen helps build cell membrane walls and get yeast to multiply, but if you aerate by hand and pitch a healthy, active starter, I don't see why beers should stall.

 

[r8rphan]

think you are fine the way it looks now - a nice even push of cold onto the plastic fermentor and a heater on the other side lower. It looks like a frankestein inside that thing but it does the job well - so who cares what it looks like, right?

Yeah, I took a break from brewing (because of this problem) for a couple years, and unintentionally left the two coffee cans of sanitizer water that I had in there for blow offs, and the moisture sitting in there all that time caused the coils to rust.. So I took the whole thing outside, and wire brushed the coils, then used rust converter and then rust converter/primer on top of that, and then tie wrapped the coils/shelves back up out of the way.... So that's why it looks like that..





Does it matter if the SS air stone is 1/2 micron or 2 micron?

I was planning on buying the 1/2 micron stone from Bobby for $20 (plus shipping), but I found some deals on line that have the tee, two 1/2" NPT x 1/2" barb adapters, and a 2 micron stone for about the same price as his delivered, all SS with free shipping...

If there is no performance difference between the two sizes, then that is a much better deal... I don't really need the tee or the adapters, but it would be nice to have them for the future.... I'll def use them somewhere...

 

[day_trippr]

There is an efficiency advantage with a .5u stone - which can be entirely countered with a 2u stone by more time if one is just stirring wort with a wand.
But as you're planning on setting it up in-line and only get one pass, I think going with the higher performing choice is a prudent move.

Also, gas take-up improves with falling temperature, so your manual oxygenation efforts were likely very ineffective if most of the O2 exposure was when the wort was still warm (already mentioned, I now see)...

Cheers!

 

[r8rphan]

Ordered the .5 micron setup from Bobby, plus some wyeast nutrient, and some DME, so that I can increase the batch size of my brews (by adding it after the mash, during boil) until I can afford to add a couple inches of height to my keggle...

ordered some more do dads off of ebay to solve a couple more problems, but they're coming from china, so I may wait till they arrive to try again...

The second batch should have better results...

In the mean time, I'm just mixing the current homebrew 50/50 with store bought stuff and it's very drinkable that way (plus makes the store bought stuff go further).. The hops profile on the first batch is awesome, so I can tell that when I get the ferment nailed down, it's gonna be the bomb....

 

[r8rphan]

Will be using oxygen (in line at the fermenter) for the first time tomorrow...

I'm at 4200' elevation.. How long do I inject oxygen into the wort for 12.5 gallons into the fermenter? (minimum/maximum time)

What pressure do I set it to (4 lpm?)