How to test if really is oxygen in bottle

[Wheelspin]

Some time ago, a friend go mine gave me a massive oxygen bottle filled, he says, with oxygen. It should last me for years.

I have used it quite extensively to aerate my wort with SS diffusion stone. However, my FG has usually been a bit off since using the what I surmise is pure oxygen. Usually setting at around 1,012 - 1,015. I'm looking for around 1.008.

I did 3 batches over the weekend and divided each in half. Half with fermeter shaken for 7 min the other halves oxygenated with the diffusion stone. I'm going to check how they ferment out in a week or two.

In the meantime, is there anyway to determine if it is indeed oxygen in the bottle ?

Any suggestions much appreciated.

 

[Gameface]

Well, since you're not in the U.S. I'm not as sure about the answer, but here O2 bottles are threaded the opposite way and are marked as O2 bottles. No gas supplier would fill it with anything but O2. I assume it is at least somewhat similar there.

 

[Brew_Dude41]

This what I remember doing from chemistry 20 odd years ago:
"A common lab procedure taught in my chemistry classes in high school was to perform a "splint" test. To test for the presence of oxygen, you would light the end of a wooden splint and reduce the flame to the point that the end of the splint is simply glowing red but not burning. Insert the glowing end into the unknown gas's container and observe what happens. If the flame returns, the gas is oxygen."

Short of finding a gas spectrometer somewhere I would use that as a pretty good indicator.

 

[Wheelspin]

Thanks guys. The bottle says oxygen so I'll try there splint. Should i just gas up a coffee cup and inset the splint ?

Maybe I'm over oxygenating ? I do 1 min 30 sec for for 5 glass.

 

[sandyeggoxj]

Thanks guys. The bottle says oxygen so I'll try there splint. Should i just gas up a coffee cup and inset the splint ?

Maybe I'm over oxygenating ? I do 1 min 30 sec for for 5 glass.

Depends on your flow rate and stone size. I push at least .5lpm for 3 minutes to my beers through a .5 micron stone. It works out wonderful. I get fantastic attenuation.

Something you didn't mention was pitching rate. Even super healthy and happy yeast cells can't work hard enough to get full attenuation if there are not enough cells. Additionally, temperature and time comes into play. What strain at what temperature and for what length of time? Also, what temperature do you mash at and how do you verify that temperature.

 

[mikescooling]

I did the splint test in college Chem, but I don't think it was pure O2 that we made. Any time you're thinking about lighting O2, I'd have a safety meeting. Do you have a torch set that you could hook up? Again were back to lighting O2, but at least the torch had a regulator and flow check valves. Oxygen tanks have threads you can't mix up with other tanks (at least here in the US). You could look the tank up and see who make it and what it's used for.

 

[yeahfairly]

For some reason I keep picturing Wyle E. Coyote and the Roadrunner!!!!!!

 

[Wheelspin]

I braced myself and did the "splint" test. Indeed it did re-light again so it must be oxygen. Quite amazing actually.

Must say I'm a bit disapointed as I thought I might have found the reason for my sometimes iffy FG readings.

 

[acidrain]

I braced myself and did the "splint" test. Indeed it did re-light again so it must be oxygen. Quite amazing actually.

Must say I'm a bit disapointed as I thought I might have found the reason for my sometimes iffy FG readings.

You didn't comment on your pitch rate. What are they? Are you using software?

 

[Wheelspin]

I use a variety of dry yeasts ranging from Notties to Saf 04, 05, 06, Munich Wheat beer yeast, BRY97 and Abbay.

Mash at around 64C, all yeasts rehydrated with plain water as per instructions, yeast nutrient last 10 min of boil and oxygenated for 90 sec with SS diffusion stone. Ferm temps in my STC 1000 controlled fermentation chambers hover around 17C to 18C.

Most of my OG's are in the late 1,050's.

What else can I do ?