Hydrometre Accuracy?

[Tje]

Hey guys,

It's now day 8 since I started my first brew. Iv'e taken hydrometre readings for the past 2 days both which were 1016. Which I thought was a bit high but I didn't follow the instructions in the kit to a tee so thought this may be resonable. However just to be sure I was going to test again today but I droped and smashed my hydrometre.

I went and bought a new one (same brand) and now its showing 1007.

Could this sudden drop in a day be due to changing hydrometres or could my beer be fermenting again?

By the way its coopers lager using s-04 (ale) yeast if that helps.

Cheers Tje

 

[MarkBastard]

You didn't buy one of those hydros from the supermarket did you?

Anyway put it in some tap water and tell us what the reading says and if possible measure the temp of the same water and tell us that too

 

[dans6401]

What was the O.G?
Can you still hear it bubbling every now and then? (Assume you're using an lid/airlock)

 

[Pollux]

Dan, an airlock can continue to bubble once fermentation has completed due to the dissolved CO2 in the beer being released and causing enough pressure to cause a "bloop".


I second the checking of both hydros in some water at 20deg, distilled if you can. Actually, that's a thought, did you check the temp of the beer when taking readings?

 

[bradsbrew]

You didn't buy one of those hydros from the supermarket did you?

Anyway put it in some tap water and tell us what the reading says and if possible measure the temp of the same water and tell us that too

+1 on this. In water the hydro should read 1.000 if the water is at the same temp the hydro is calibrated at, which is normally 20 degree but I have seen some at 15 degree.

 

[Damian44]

Dan, an airlock can continue to bubble once fermentation has completed due to the dissolved CO2 in the beer being released and causing enough pressure to cause a "bloop".


I second the checking of both hydros in some water at 20deg, distilled if you can. Actually, that's a thought, did you check the temp of the beer when taking readings?

Sorry to go off topic on ya Tje but Pollux's comments got me thinking. On my last brew i crashed chilled the fermenter after it reached FG. At least i thought it had reached its FG, the wort was 12C and i adjusted it in Beersmith.
When i took the fermentor out to keg, it started bubbling away like it was high krausen. Could this be as Pollux says from "dissolved CO2"?

 

[Pollux]

Easy way to show my point, chill a keg, carb it as per your usual way. Vent it and now leave it to warm to room temp.......

I can assure you it will be able to vent off alot of gas again...

 

[Tje]

You didn't buy one of those hydros from the supermarket did you?

Anyway put it in some tap water and tell us what the reading says and if possible measure the temp of the same water and tell us that too

No I didn't buy it from the supermarket. My first one came with my kit and the second one I bought from my LHBS.

I just measured it in water at 21 degrees and it read 0.960.

I forgot to note what the temperature was during my last readings though I didn't realise it was so important until now....but from memory the first two days I took a reading it was about 26 degrees (yes I know a bit too hot for my brew but I've learnt) and the third day i belive it was a little cooler around 23 degrees.

Oh and by the way my hydrometre is calibrated at 20 degrees and my OG was 1.041

Thanks for all your help

 

[MarkBastard]

I just measured it in water at 21 degrees and it read 0.960.

Oh and by the way my hydrometre is calibrated at 20 degrees

Your hydrometre is out.

 

[Nick JD]

Your hydrometre is out.

And French.

 

[Murcluf]

And French.

it could be worse and be Chinese....!

 

[Nick JD]

it could be worse and be Chinese....!

液體比重計 (hydrometer)

 

[beersom]

Your hydrometre is out.

By my calcs .960 at 21 is equal to 0 at 20 ..... Hydrometer is fine

 

[Tje]

Your hydrometre is out.

Damn I only bought the thing yesterday. Any sugestions? Better brands etc?

Will it matter if I use a hydrometre that is out because I'm going to be using the same hydrometre (as long as I don't break it again) so shouldn't it give me a constant reading anyway?

 

[glaab]

By my calcs .960 at 21 is equal to 0 at 20 ..... Hydrometer is fine

I think you mean 1.0?
BS hydro tool says 0.960 at 21 is equal to 0.960 at 20.
Take it back if you just bought it

 

[MarkBastard]

By my calcs .960 at 21 is equal to 0 at 20 ..... Hydrometer is fine

By my calcs .960 at 21 is equal to 0 at 103 degrees. Doubt he's putting it in boiling water and if he is there'd be other problems affecting the reading, like uhh boiling water perhaps.

Tje, you can assume that the hydrometer is out in a constant way, so you can add .04 to your readings across the board and it may prove to be accurate. But to be honest if I'd just bought a hydro and it was that far out I'd take it back and I'd be worried it won't be measuring correctly for starting gravity either.

 

[felten]

I believe most hydrometers have all the measurements on a simple roll of paper inside their necks, I've heard they can become unseated and cause a bad reading. With all the money spent on hydrometers, you could have gone out and bought a refractometer instead!

 

[mika]

My Brother had a Hyrometer that was a smidgen out in water, but in a fermenting beer, compared to the Hydro I have (same brand as it turns out) his Hydro read 4pts higher than mine.
He's since bought another Hydro which appears to be a lot closer.
So... yeah.... not very accurate, to answer the topic question

 

[Tje]

Ok thanks for all your help. I ended up assuming that yes it is inacurate but it will be inacurate in it's own way, It gave me a constant reading over three days so I bottled.
Thanks again,
Trent

 

[beersom]

By my calcs .960 at 21 is equal to 0 at 103 degrees.

Simple typo on my behalf relating to the fact that I work in plato rather than sg.... looked at the wrong calc