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
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
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
Ok, thanks for that Bill. There are lots of beer programs out there but the all stop at 0° plato or 0.100 specific gravity.
Ok, thanks for that Bill. There are lots of beer programs out there but the all stop at 0° 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 2.0% was 1.006 at 20 CHis value for thermal expansion came to:
-0.32 at 0% sugar at 10%
0.3 cane sugar = 0.9994Summing 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:
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