Plum wine questions

[ericbw]

I have a small batch fermenting right now. Very basic recipe - 5 pounds of pitted plums, 2 pounds white sugar, 1 gallon water, half a packet of Pasteur Champagne yeast. I put the sugar and plums in a bucket, added hot water and stirred. I added the yeast when the temp was at 103.

At 2 weeks, I strained out the fruit and am letting it settle ~ 2 days before racking to another fermenter.

Is there any way to know how much sugar/gravity the plums contribute? I took a reading when I strained, and it is under 1.000 (the scale starts at 0, so it might be .995-.998ish?). I know the OG was at least 1.072 from the sugar. I know all fruit is different, depends on a lot of factors, etc. But I'm looking for some guideline or range of what the plums might have contributed.

Any ideas/guesses?

 

[Xandir]

You can use a hydrometer and refractometer to take FG readings and figure out the OG.

Good paper on this here:

http://www.moundtop.com/alcohol/Alcohol-via-Refractometer-Hydrometer.pdf

 

[ericbw]

You can use a hydrometer and refractometer to take FG readings and figure out the OG.

Good paper on this here:

http://www.moundtop.com/alcohol/Alcohol-via-Refractometer-Hydrometer.pdf

I don't understand the math. I can't measure Brix, but I can convert the SG reading to Brix. However, won't I always get a negative number, since I am starting with something less than 1? This might be more complex than I can understand math-wise.

 

[Xandir]

You have to have both a hydrometer (reads in SG) AND a refractometer (~$25 on Amazon - get the ATC model) that normally reads in Brix.

Because the two devices measure sugar differently, and the alcohol in your wine causes a predictably inaccurate FG reading on the refractometer, you can use the calculator to determine somewhat accurately what the final %ABV is.