SG increased at end of fermentation?

[ericsmithcpa]

My SG, as I was waiting for fermentation to stop, went from 0.994 to 0.995. Slight, but very obvious change. I was expecting it to be around 0.992, and it actually increased!

I’m using the same hydrometer, at the same temperature, and I have hydrometer pictures so it’s clear that I didn’t just read it wrong. Also, I have a precision finishing hydrometer so it’s an unambiguous increase.

Any thoughts?

 

[cmason1957]

It could be Co2 pushing your hydrometer up every so slightly. I always wonder why folks think it has to get down to 0.990 to be dry. I'll take anything below 0.996 and call it dry.

 

[1d10t]

My SG, as I was waiting for fermentation to stop, went from 0.994 to 0.995. Slight, but very obvious change. I was expecting it to be around 0.992, and it actually increased!

I’m using the same hydrometer, at the same temperature, and I have hydrometer pictures so it’s clear that I didn’t just read it wrong. Also, I have a precision finishing hydrometer so it’s an unambiguous increase.

Any thoughts?

What equipment are you using to measure the SG that you are that confident of the precision of your readings?

 

[Ajmassa]

Possibly less co2 remaining in wine at 2nd reading? Or 1st reading not true representation of entire volume or vice versa? That minor of a change tho I wouldn’t bat an eye. (Unless it continues to increase) and could be a lot of reasons.
And would be more than happy with .995 or .994.
Because it’s impossible for residual to “reappear”. Can’t lose abv (as far as I know) so only logical explanation is a reading was not true somewhere along the line.
*this is not financial advice. Lol. And I am not a chemist. Just my 2¢

 

[ericsmithcpa]

What equipment are you using to measure the SG that you are that confident of the precision of your readings?

it measures 1.000 in water, and I didn’t change hydrometers so even if it’s not accurate, an increase is an increase. Shrug...

Precision Finished Hydrometer https://www.amazon.com/dp/B00838XR1K/ref=cm_sw_r_cp_api_i_klFVDb76SAZE3

 

[ericsmithcpa]

Possibly less co2 remaining in wine at 2nd reading? Or 1st reading not true representation of entire volume or vice versa? That minor of a change tho I wouldn’t bat an eye. (Unless it continues to increase) and could be a lot of reasons.
And would be more than happy with .995 or .994.
Because it’s impossible for residual to “reappear”. Can’t lose abv (as far as I know) so only logical explanation is a reading was not true somewhere along the line.
*this is not financial advice. Lol. And I am not a chemist. Just my 2¢

Maybe stirring caused dissolution of solids other than sugar or something... this makes sense. thank you. Racking!

 

[Ajmassa]

it measures 1.000 in water, and I didn’t change hydrometers so even if it’s not accurate, an increase is an increase. Shrug...

Precision Finished Hydrometer https://www.amazon.com/dp/B00838XR1K/ref=cm_sw_r_cp_api_i_klFVDb76SAZE3

But it’s not an actual increase in sugar. The Only increase is in your readings. Sugar cannot “come back” and abv doesn’t fade. The only explanation is an unknown variable affecting one of the readings.

And again, we’re talkin .001 change.
Are you pulling samples or dropping straight into the fermenter? Are you degassing first? Was wine mixed beforehand?

You sound disappointed. But .995 is dry. 998 is dry. .992 is much less common. Once dry wherever it finishes it finishes. And still very much a full successful fermentation to dry — for the hobbyist and for the pros.

 

[ericsmithcpa]

But it’s not an actual increase in sugar. The Only increase is in your readings. Sugar cannot “come back” and abv doesn’t fade. The only explanation is an unknown variable affecting one of the readings.

And again, we’re talkin .001 change.
Are you pulling samples or dropping straight into the fermenter? Are you degassing first? Was wine mixed beforehand?

You sound disappointed. But .995 is dry. 998 is dry. .992 is much less common. Once dry wherever it finishes it finishes. And still very much a full successful fermentation to dry — for the hobbyist and for the pros.

Yes I had a couple batches ferment lower so I expected this one to ferment to .992 or so also. Probably more a problem with my expectations for my lack of experience.

I do pull samples rather than drop the hydrometer in the fermenter. I think I stirred it this time, and didn’t stir it last time. So that may be the difference. I’ll count it as a success and put in a carboy in the corner with some oak for a year or so!

 

[Ajmassa]

Btw- what type of wine are ya making?

 

[gsf77]

it measures 1.000 in water, and I didn’t change hydrometers so even if it’s not accurate, an increase is an increase. Shrug...

Precision Finished Hydrometer https://www.amazon.com/dp/B00838XR1K/ref=cm_sw_r_cp_api_i_klFVDb76SAZE3

I'm asking a question that pretty obvious by looking at it - That "Precision Finished Hydrometer" (PFH) appears to be a different animal from the triple scale hydrometer. I have the triple scale - would it be in my best interest for me to invest in a PFH? I plan to make my own wine for many years to come.

 

[Scooter68]

At that price, hope you buy a really good case for it and get a LOT of use of it. Really, final SG isn't that critical. If you are within .002 +/- you are going to be fine. When in doubt, remove it wipe it down give it a spin as you drop it back in. CO2 can cause errors in reading if you leave it there long enough, and keep in mind - that PFH is lighter in weight than a standard hydrometer so CO2 can much more easily affect it's readings.

 

[CabSauv]

You probably had some fizzing or wine climbing up the hydrometer, so your first reading could have been higher than you first thought. If it hasn't changed in 3 days then it's done.

 

[jsbeckton]

I also have a narrow range finishing hydrometer and personally love it for both beer and wine. It’s takes a lot of the guesswork out of the equation for exactly where you end up. Not necessary but very handy IMO especially for beer where the starting and finishing gravity are much closer so the ABV calculation is actually appreciably impacted by a few points.