Jim wrote "I'm not after n'th degrees here, just a reasonable 'likely PA' to

help me make easy decisions."

Jim, if you just want a reasonable *** prediction here's a pretty simple

approach. These equations assume a wine ferments to dryness. Even though a

hydrometer will display a negative number for a dry wine, I assume the end

point is 1.000 because you can't ferment anything that wasn't there in the

first place. And, the negative hydrometer reading for a wine at dryness is

due to the influence of ***. By using only the starting specific gravity

value there is no influence of ***. Therefore, I use the difference

between starting specific gravity and 1.000 in the calculation.

*** By Volume Calculation

Reference; "Homebrewing, Volume 1", by Al Korzonas, pg 31

og = original specific gravity

fg = final specific gravity (in the case of wine 1.000)

Calculation of *** by weight;

%ABW = (og - fg) x 105

Calculation of *** by volume;

%ABV = %ABW x 1.25

Combined method for %ABV;

%ABV = (og - fg) x 131.25

It's simple to set up the "Combined method for %ABV" equation in a

spreadsheet...then just plug in the starting specific gravity and get your

answer. All you need is a hydrometer that reads in specific gravity...no

charts, no tables.

Bill Frazier

Olathe, Kansas USA

I will indeed be after a hydrometer which matches some published

Quote:

> scales at least. The SG readings make the grade thankfully for now.

> That just leaves me claculating residual sugar in my cranberry-currant

> wine which is looking dangerously high this close to transfer to secondary

> at 1060 with two days to go (out of 7 projected at 20C or so) at an

> average temperature of 21C . Damn my attempts to convert and scale up US

> Pints to UK litres from a 1 - 6 gallon (US quantities) My maths will let

> me down even ifmy hydrometer doesn't.

> As Terry Garey tells me, 'time is on your side'! A good job, since this

> newbie in the UK is wishing that they bought a triple scale hydrometer at

> the other shop... Seriously, thanks to everyone who replies as well as

> reads (and without prejudice) you help a very new winemaker to learn by

> his mistakes...

> Jim

>>> I found 5 different ways PA calculations

>>> here:http://www.FoundCollection.com/

>>> Thanks for your comments though.

>> Jim,

>> That is a very good reference, Ben is very well informed. Those

>> references I was talking about in 'Principles and Practices of

>> Winemaking' are very similar to what Ben describes. The reason I

>> mentioned 60 years was that one of the last good references written (in

>> the US) was by Bates called Polarimetry, Saccharimetry and the Sugars

>> in 1943 or so. NIST still used that reference to calibrate hydrometers

>> last time I checked. I got a used copy (because I'm a geek and had to

>> know...) :)

>> Joe.