I'm an old brewer and a new wine maker.

I took a gravity sample last fall of a red wine I made and it was
1.094. Since then I broke my hydrometer.

My back-up Hydrometer only has a 'plato' beer scale and it stops at 0°
plato.

I took a measurement of my wine today and it was -2 plato and the
temperature was 10° celsius, the hydrometer is rated to be measured at
20°celsius.

So can anyone tell me what my specific gravity is?

TIA

Phil

Phil - I think it's about 0.992. I didn't correct for temperature. I use a
simple formula for conversion of Plato or Brix to Specific Gravity. I
found the formula years ago...it was authored by William Secor.

specific gravity = 259/259-P

Bill Frazier
Olathe, Kansas USA



"Phil" > wrote in message
om...
> I'm an old brewer and a new wine maker.
>
> I took a gravity sample last fall of a red wine I made and it was
> 1.094. Since then I broke my hydrometer.
>
> My back-up Hydrometer only has a 'plato' beer scale and it stops at 0°
> plato.
>
> I took a measurement of my wine today and it was -2 plato and the
> temperature was 10° celsius, the hydrometer is rated to be measured at
> 20°celsius.
>
> So can anyone tell me what my specific gravity is?
>
> TIA
>
> Phil

William Frazier wrote:
> Phil - I think it's about 0.992. I didn't correct for temperature.
I use a
> simple formula for conversion of Plato or Brix to Specific Gravity.
I
> found the formula years ago...it was authored by William Secor.
>
> specific gravity =3D 259/259-P
>
> Bill Frazier
> Olathe, Kansas USA


Ok, thanks for that Bill. There are lots of beer programs out there
but the all stop at 0=B0 plato or 0.100 specific gravity.

William Frazier wrote:
> Phil - I think it's about 0.992. I didn't correct for temperature.
I use a
> simple formula for conversion of Plato or Brix to Specific Gravity.
I
> found the formula years ago...it was authored by William Secor.
>
> specific gravity =3D 259/259-P
>
> Bill Frazier
> Olathe, Kansas USA


Ok, thanks for that Bill. There are lots of beer programs out there
but the all stop at 0=B0 plato or 0.100 specific gravity.

Hi Phil,
Plato actually did the definitive work in Hydrometry back in 1900. His
scale did not go negative though, I have his values in a reference.
(He used cane sugar and pure water, so it couldn't.) Those negative
values must be extrapolated (assuming a certain amount of alcohol I
would assume, but I do not know for a certainty).


That said, he measured:

22.9% cane sugar at 1.094 at 20 C
2=2E0% was 1.006 at 20 C

His value for thermal expansion came to:

-0.32 at 0% sugar at 10%

0=2E3 cane sugar =3D 0.9994

Summing them I come up with 0.995 which is pretty close to Bill's
value. Summing them can't be right, if you look at a hyrdometer
closely you will see the scale is not linear. It's the best I can do
though.

All of this assumes that both hyrdometers would have read 1.000 at 20 C
in distilled water. That may not be a good assumption in my
experience.

If you are really looking for dryness or residual sugasr, you may want
to consider clinitest tablets.

Hope that helps.

Joe

Phil wrote:
> I'm an old brewer and a new wine maker.
>
> I took a gravity sample last fall of a red wine I made and it was
> 1.094. Since then I broke my hydrometer.
>
> My back-up Hydrometer only has a 'plato' beer scale and it stops at
0=B0
> plato.
>
> I took a measurement of my wine today and it was -2 plato and the
> temperature was 10=B0 celsius, the hydrometer is rated to be measured
at
> 20=B0celsius.
>
> So can anyone tell me what my specific gravity is?
>=20
> TIA
>=20
> Phil