Ha ha, I don't think there can be a logical fight when there are several ways to calculate it. I just mean that after
my thread about far out my hydrometer's PA scale was, a good general guide in the calculator was a good thing, hence the
wink

I had to state the same bsquared table as you did Pp to demonstrate just how confused I was about PA and why there
weren't absolutes. My PA scale doesn't equate to any of those five either. I wondered what the Scottish makers of my
hydrometer were basing their callibration on and couldn't find a scale in agreement with them.

I'm just grateful for the tool, and for opinions and information so generously shared here by the winemaking community.

Jim

"pp" > wrote in message ups.com...
> Steve:
>
> No fight here. I noticed the 2 results closely correlate but that
> could just mean one formula could be derived from the other the real
> test is judging the computed results against measured values. The
> practical problem with this is we don't seem to have ready access to
> measured alcohol values so it's hard to support any result well.
>
> Some people discard D&A's work because they argue considering the
> final gravity is plain wrong because anything that goes under sg 1.0
> is just the effect of alcohol created from the sugar (which is
> captured by initial s.g. value). That would also apply to Balling's
> formula. This is more pronounced for wines where often the final s.g.
> can get to 0.990 for dry wines.
>
> Personally, I think that argument is faulty because it ignores how the
> formula was designed - it's just as easy to base the PA values solely
> on the initial s.g. as it is to base them on the difference between
> final and initial s.g. The latter does not artifically "add sugar
> that's not there", it just incorporates the fact that the sugar
> progressively changes into alcohol and bases the calculation on that.
> The results will not completely agree but it's just an estimate anyway
> because the actual alcohol depends on many factors that cannot really
> be measured in practice.
>
> That said, based on the s.g. values of the grapes and juice we
> routinely get from California these days, I think the D&A formula
> exagerates the PA values by about 0.5-1% of abv. Again, this is
> imprecise as it's based on taste comparisons of my wines with
> commercial wines with stated alcohol value, but it works for me and
> that's really what matters in the end .
>
> You might want to check out this page: http://www.brsquared.org/wine/
> in the Calcs/Info section, it has some other formulas from the
> literature. Actaully, given that you're already showing 2 different
> values anyway, it might be of real value to collect all the different
> formulas you can get hands on and add those to the applet, kind of
> like what Ben has in his table but more extensive. That would give
> people a full range of PA results comparison in one place; I think
> that'd be really useful.
>
> One final note on the subject of precision - I think all calculations
> should be round up to give the PA values in 0.5% increments. Anything
> more than that gives a false impression that the computed value is the
> exact amount of alcohol in the wine, which is at odds of what the
> formulas can really do.
>
> Sorry, I've made this longer than I wanted - I keep promising myself I
> won't get involved in these debates anymore but it doesn't seem to
> work...
>
> Pp