Reading the Gravity

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Grumbler
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Reading the Gravity

Post by Grumbler » Wed Feb 15, 2017 10:40 pm

Hi all, its me again! I just took ing of my cerveza I started Saturday. I let it settle then read 1.024. I got distracted by the boss and went back 20 mins later. The reading was 1.008. Does this show the suspended sugar settling? When is the most accurate reading? Immediately or after a certain length of time?

dbambrick996
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Re: Reading the Gravity

Post by dbambrick996 » Wed Feb 15, 2017 10:48 pm

Sugar doesn't suspend the yeast eats the sugar.

Take a gravity reading after you cooled wort is in the fermenter at pitching temperature, this is your original gravity reading. As fermentation goes on the yeast eats sugar and the gravity readings drop.

Couple of things you could look at, human error, or an inaccurate hydrometer. Also the temperature you sample at will effect your reading.

Can you check your hydrometer on room temperature water, it should read zero.

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Chug
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Re: Reading the Gravity

Post by Chug » Wed Feb 15, 2017 11:06 pm

A gravity drop like that over 20 mins is not possible, so either your first or second, or both, readings were wrong, most hydrometers are calibrated to read zero in water @ 20C and all readings should be taken at this temp.

Grumbler
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Re: Reading the Gravity

Post by Grumbler » Thu Feb 16, 2017 2:50 pm

Thanks for the response. I tried the same beer with a different hydrometer and it read 1.010. Tried both hydrometers at room temperature and one read 1.002, with tap water I hasten to add. I cant explain the difference in reading over 20 minutes though, as I took the readings in the same room and on the same surface. I'll do it again Saturday just to see what happens.

McMullan
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Re: Reading the Gravity

Post by McMullan » Thu Feb 16, 2017 3:11 pm

The sample may have been saturated with CO2 when it was first taken from the FV. While you were away, it degassed?

oldbloke
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Re: Reading the Gravity

Post by oldbloke » Thu Feb 16, 2017 4:50 pm

McMullan wrote:The sample may have been saturated with CO2 when it was first taken from the FV. While you were away, it degassed?
That's my guess

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Chug
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Re: Reading the Gravity

Post by Chug » Thu Feb 16, 2017 11:08 pm

Saturated with co2 :?: what? Do you guys wait awhile to let it degass before taking readings then, or do you degass your samples somehow just in case?

McMullan
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Re: Reading the Gravity

Post by McMullan » Fri Feb 17, 2017 12:05 pm

Some strains are very 'gassy'. Part conditioned beer in an FV after less than a week isn't unusual. If so, pour back and forth a few times between two cups, for an accurate reading.

jaroporter
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Re: Reading the Gravity

Post by jaroporter » Fri Feb 17, 2017 3:45 pm

the obvious effect of the co2 is that the bubbles coming out of solution and rising to a head physically lift the hydrometer, giving a falsely high reading.

does the solution of co2 in the beer also i guess affect the density of the sample, therefore gravity reading also, in the same way that alcohol does?
dazzled, doused in gin..

Grumbler
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Re: Reading the Gravity

Post by Grumbler » Sat Feb 18, 2017 8:26 pm

Thanks MacMullan, that has got to be the reason as it was fizzy when I drank a bit. Tasted sweet, so as it's still showing signs of fermentation I'll try again before I bottle to see how many carb drops I need to put in. Just tried my Wherry with cascade hop tea, very happy! Thanks again fellas, its a learning curve and your help is appreciated.

Fil
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Re: Reading the Gravity

Post by Fil » Mon Feb 20, 2017 5:02 am

generally giving the hydrometer a spin between thumb and finger throws off any co2 bubbles that rise and stick to it, just grab it to still it and take a reading before any more rise up and stick to it ;)
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

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