Fermentation Gravity Readings

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Bee
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Fermentation Gravity Readings

Post by Bee » Tue Feb 02, 2021 1:40 pm

Is it possible to get accurate wash gravity readings while it's fermenting?
I tried, but I think the bubbles are buoying the hydrometer.

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Demy
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Re: Fermentation Gravity Readings

Post by Demy » Tue Feb 02, 2021 2:59 pm

If you are measuring while there is carbon dioxide present I suggest you degas the liquid before the measurement. You can do this in different ways for example take the sample to be measured and shake it in a jar several times. Carbon dioxide tends to distort the reading.

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Re: Fermentation Gravity Readings

Post by SnowJeeper » Tue Feb 02, 2021 3:05 pm

Try spinning the hydrometer really fast. Grasp the top between your thumb and forefinger and let it rip. That should spin off most of the bubbles.

Alternatively you can just wait and they’ll eventually disappear

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Re: Fermentation Gravity Readings

Post by still_stirrin » Tue Feb 02, 2021 7:00 pm

SnowJeeper wrote:
Tue Feb 02, 2021 3:05 pm
Try spinning the hydrometer really fast. Grasp the top between your thumb and forefinger and let it rip. That should spin off most of the bubbles.
+1. Works for me.
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Re: Fermentation Gravity Readings

Post by Demy » Wed Feb 03, 2021 5:13 am

From what I have personally found, simply rotating the hydrometer will stabilize it but there can still be a reading error as long as the liquid is sparkling. It's not a big mistake (a couple of points at most) but there can be. I usually fill the test cylinder, close the top part with my hand, shake it a few times and wait a few seconds for the foam to go away then immerse the densimeter. It also depends at what moment the measurement takes place, for example if it is in full fermentation, the measurement is certainly a bit distorted.

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Re: Fermentation Gravity Readings

Post by Birrofilo » Wed Feb 03, 2021 8:42 am

My degassing strategy is to put the wort or beer or sugar wash in a plastic bottle, of the carbonated drink or water type. I close the cap and stir vigorously, then I open the cap, I hear the gas getting out, and repeat for a few times.
For beers I stir until I only have froth, and I measure to the density of the sample when it has become liquid again.

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Re: Fermentation Gravity Readings

Post by OldSmitty » Wed Feb 03, 2021 9:01 am

TBH I've only done one mid-fermentation gravity reading. I was hoping to run my 1st stripping run off my 1st sugar wash last weekend. The hydrometer told me there was no way it would finish by Sunday, so that was good enough for me.

If you're providing a reasonable OG, adequate nutrients, adequate fresh yeast, and proper fermentation temps, the yeast will git 'er done. What's your end goal for taking accurate mid-fermentation SG readings?

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Re: Fermentation Gravity Readings

Post by Prairiepiss » Wed Feb 03, 2021 8:17 pm

If it’s still working why you messing with it? Let them yeasties work it off then mess with it. I mean you know it ain’t done if it’s still working. And you ain’t Gona run it when it’s still working. That would be a waste. So let it finish out. And leave them yeasties alone.
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Re: Fermentation Gravity Readings

Post by Saltbush Bill » Thu Feb 04, 2021 2:33 am

Prairiepiss wrote:
Wed Feb 03, 2021 8:17 pm
If it’s still working why you messing with it? Let them yeasties work it off then mess with it.
100% agree with that .....if its working that hard that its holding the hydrometer up, its not just degassing ...its still fermenting......leave it to do the job its trying to do.
Stop over thinking things ..KISS principle.

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Re: Fermentation Gravity Readings

Post by Bee » Thu Feb 04, 2021 5:18 am

LOL! You know I gotta futz with it! :lol:

Just curious how it's progressing.

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Re: Fermentation Gravity Readings

Post by Prairiepiss » Thu Feb 04, 2021 8:54 am

Bee wrote:
Thu Feb 04, 2021 5:18 am
LOL! You know I gotta futz with it! :lol:

Just curious how it's progressing.
The more you futz with it. The greater chance of an infection or any number of other things. Just sit on you hands and keep your booger hookers out of it. You know it’s progressing. That’s all you need to know.

Start another ferment or do something else. Just let it do it’s thing.
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Re: Fermentation Gravity Readings

Post by OldSmitty » Thu Feb 04, 2021 9:34 am

Bee,

I feel your pain, but you gotta trust the process. My 1st wash is going slower than I'd like due to trying bakers yeast at room temp since that sounded easier than figuring out a hot box in winter. Homebrewing taught me it's better to stay the course, learn a lesson, and do better next time.

I made a high SG beer once and only pitched one yeast packet cuz I was too cheap for two. It didn't ferment out completely tasting too sweet and of acetaldehyde. "Smart" me thought, no problem just add that 2nd pack of yeast I should have used. It turns out when you add powder to a mixture holding residual CO2, that powder will dislodge the CO2 in solution which caused it to foam up like a science fair volcano. My dark beer foamed up and out of the carboy all over my nice light colored carpet. I tried my best to use a carpet cleaner to get the dark stain out, but the missus could still point to the spot on the carpet with pinpoint accuracy. That beer never did finish right.

Point is opening up a fermenter during fermentation has never rewarded me. It's only caused poor decisions to be made. After pitching yeast, I've never had a successful intervention (and I've had a few other screw-ups).

Prep it right, pitch it right, temp it right, and the yeast will reward you. At this point, just let it... bee.

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