What is your approach to degas beer for a Gravity reading?

Box of Rocks

Box of Rocks

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Question for those fermenting under pressure - how do you degas your beer sample to take a gravity reading? My hydrometer requires about 7 ounces to float. Have been tossing beer from glass to glass for an eternity, and still have bubbles…
 
Pour from glass to glass let sit for a minute or two pour Into hyrldro flask with hydrometer in place so any remaining foam pours over edge of sample flask

I'f still carbonation give the hydrometer a giggle and spin to keep the bubbles off it.
 
So wait a tick... Let's just say my beer was carbed to about 4 psi at 35F (which appears to be almost 2 volumes?) and I spun the hydrometer but did not de-gas the beer at all. Did I get an accurate reading?
 
Strain it through a cheese cloth or muslin bag. Paper towels take longer, coffee filters will remove the co2, but it take forever to pass through. Several passes may be necessary. You could use a refractometer, but sometimes I had some results that seemed off even with the calculator to help with the alcohol present.

If you don't get all the gas out, it will show a higher FG.
 
I guess your goal would need to be known too.
Do you want to know the actual SG or just want to know that the yeast is done?

If the latter, use a refractometer. Take a reading, don't bother with correction. 2-3 days later, take another reading. If the reading is the same, its the same. Its prolly done. Even if the reading is not the actual SG, if it is the same. No more activity exist
 
Unless there are bubbles actively clinging to the hydrometer, it's going to be accurate to within the margin of error that's inherent with the typical cramped hydrometer scale and cling-inducing flask. :D :D
 
I think I'll pull some from the (fully-carbed) keg and decarb it, re-measure.
The issue was FG was way high, only about 50% attenuation, and that triggered a troubleshooting session...

My Tilt said the beer had finished some time ago, that's not the issue.
 
Donoroto said:
So wait a tick... Let's just say my beer was carbed to about 4 psi at 35F (which appears to be almost 2 volumes?) and I spun the hydrometer but did not de-gas the beer at all. Did I get an accurate reading?
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Probably not. If the beer didn't foam, it still had gas. We degas wine by putting a paint stir device on a drill and spinning it for two minutes. Spinning the hydrometer for a few seconds is not going to get all the gas out of your beer. As JA said, it's bubbles clinging to the hydrometer that make it more buoyant than it should be, making the beer appear to be more dense than it actually is.
 
just curious, it occurs to me that if the liquid has alot of co2 dissolved in it. wont this effect the gravity in and of itself? (regardless of bubbles on the hydrometer)
 
Minbari said:
just curious, it occurs to me that if the liquid has alot of co2 dissolved in it. wont this effect the gravity in and of itself? (regardless of bubbles on the hydrometer)
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I think so. Just because we can’t see the bubbles doesn’t mean they aren’t there.
 
It depends on the specific gravity of the dissolved CO2. I vote that the liquid gets fluffier, and so has a lower SG.

In reality, the dissolved CO2 'fills in' the spaces between the water molecules, increasing mass without increasing volume.
 
I think your second argument is closer to the truth. Since we're adding mass but not volume, as long as the liquid is not bubbling, the SG will go up. We may not be able to measure it with our equipment. Bubbles cause the hydrometer to float higher, giving the appearance of higher gravity. That would affect the refractive index as well, making a refractometer unreliable as well. Degassing to measure the gravity of carbonated beer seems to be the only way to get an accurate reading.
 
Ok, so I decarbed a sample and got 1.022 instead of 1.026. That sets attenuation closer to the goal. The beer is a little sweet, not overly so, yet I remain pleased with how it came out. Next time I'll cut the 'brown' a bit, but not by much, and I think it'll end up perfect. For me at least.
 
I think going to a lot of extra measures is overkill and really just splitting hairs in the end.
Maybe 1 extra pour between a sample cup and then into a test jar should be sufficient.
In the end, if you're a point or 2 off, you're still within a margin of error.
 
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Ultimately my degassing gave me comfort that I'm close to enough to terminal gravity for government work. Target for this batch was 1.038 for OG, and 1.012 for FG. Actual OG was 1.035 and FG was 1.014. Instead of ABV slightly above 3%, it’s slightly below. Attenuation was super low at 60% vs. expected of 75%, perhaps explained by an initial temperature spike or …? Cold crashing now.

I’m calling this English Mild - “Quite. Quite. Indubitably Mild.” Best uttered while lighting/puffing a pipe.
 
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Rockhead said:
View attachment 17421 Ultimately my degassing gave me comfort that I'm close to enough to terminal gravity for government work. Target for this batch was 1.038 for OG, and 1.012 for FG. Actual OG was 1.035 and FG was 1.014. Instead of ABV slightly above 3%, it’s slightly below. Attenuation was super low at 60% vs. expected of 75%, perhaps explained by an initial temperature spike or …? Cold crashing now.

I’m calling this English Mild - “Quite. Quite. Indubitably Mild.” Best uttered while lighting/puffing a pipe.
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Yeah in regards to low attenuation I wouldnt expect a temp rise to cause it unless it went beyond the yeasts high temp range like 30c
Maybe more of a vitality thing maybe alot of old yeast cells at pitch or low nutrient or Oxygen wort content.
 
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