beer test samples from a pressurized keg

[J.Miller]

Hello! I am asking for your recommendations. I want to obtain a beer sample from a corny keg pressure-fermentation. My preference is being able to do this while the keg lid is closed and the keg with a pressure in it. The sample size will need to be sufficient (±1 fl oz) for refractometer and pH pen meter testing. I got an idea on how to do this; and I will appreciate your recommendations and experiences. Or please indicate an applicable reference or prior post.

Should I have posted this in the fermentation forum?

Thanks!
Jeff

 

[VikeMan]

If this fermenter keg is under high pressure, my recommendation would be to relieve most of the pressure before drawing your sample.

If you have trouble with getting the sample, my next recommendation would be to ask yourself "why am I fermenting under high pressure in the first place?"

 

[J.Miller]

Vike, I have no experience with pressure ferments. "I have read" that spunded pressures of about 10 to 12 psi are good, so that would be my pressure range. If that pressure is too high for sampling through an attached plastic party (cobra?) tap, your prior releasing pressure is a good idea.

 

[VikeMan]

10-12 PSI should be low enough to not make too much of a mess through a picnic tap.

 

[Dexlor]

Couldn't you just use a picnic tap with a very short hose? The pressure inside should be enough to server your small sample.

 

[J.Miller]

Connected to the beer-out quick disconnect keg post with the original-length dip tube shortened about 1 inch? I was thinking about a keg lid with a third quick disconnect and a beer hose dip tube open-ended about mid-depth to reduce the amount of yeast cake in the sample. Or,? ?

 

[marc1]

Connected to the beer-out quick disconnect keg post with the original-length dip tube shortened about 1 inch? I was thinking about a keg lid with a third quick disconnect and a beer hose dip tube open-ended about mid-depth to reduce the amount of yeast cake in the sample. Or,? ?

I ferment in a Kegmenter with a CBDS floating dip tube. No problem slapping on a picnic tap and pouring a sample, even if I've increased pressure to start carbonating at the end. Foam isn't a big deal because I put a couple drops of Fermcap in the sample.

 

[doug293cz]

I ferment in a Kegmenter with a CBDS floating dip tube. No problem slapping on a picnic tap and pouring a sample, even if I've increased pressure to start carbonating at the end. Foam isn't a big deal because I put a couple drops of Fermcap in the sample.

Yup, floating dip tube is the way to go. Also, makes it easy when you want to transfer to a serving keg, maximizing the beer recovery, while minimizing any yeast/trub pick up.

Brew on

 

[J.Miller]

Hey, thanks, all !!
What is the chance that non-uniformity exists in fermenting beer? Is a sample drawn at the top approximately representative of the pH and specific gravity of the batch? I know that test sensors (such as Tilt and other branded hydrometers) are floating. This question likely has been asked a few times, but I am not familiar with research documentation of those instruments. I believe what I am asking:
- - is there a SG and pH value difference between clear and unclear beer during fermentation?

 

[doug293cz]

Hey, thanks, all !!
What is the chance that non-uniformity exists in fermenting beer? Is a sample drawn at the top approximately representative of the pH and specific gravity of the batch? I know that test sensors (such as Tilt and other branded hydrometers) are floating. This question likely has been asked a few times, but I am not familiar with research documentation of those instruments. I believe what I am asking:
- - is there a SG and pH value difference between clear and unclear beer during fermentation?

If you've ever watched an active fermentation, you will know that there is a lot of mixing going on in the bulk of the beer. Thus there will be no chemistry related gradients in the beer.

Brew on