What is the purpose and function of the PA scale on my hydrometer ??

I never really got used to the BRIX numbers....
but appreciated the specific gravity scale better: 1.090, etc.
but even better than that is just to look at PA - "potential alcohol."
and say: hmmmm, this is what I"m gonna be close to.
it's worked for me so far...12-14%.....that range



"frederick ploegman" > wrote in message
...
> What is the purpose and function of the PA scale on my hydrometer ??
>
>

Hi Rick

Yup - Most folks do it that way, and so do I. With pre-pitch readings
and calculations, everything works out just fine. It is only the
post-pitch readings that get messed up. Thanks for your answer.

Frederick

"Rick Vanderwal" > wrote in message
...
> I never really got used to the BRIX numbers....
> but appreciated the specific gravity scale better: 1.090, etc.
> but even better than that is just to look at PA - "potential alcohol."
> and say: hmmmm, this is what I"m gonna be close to.
> it's worked for me so far...12-14%.....that range
>
>
>
> "frederick ploegman" > wrote in message
> ...
> > What is the purpose and function of the PA scale on my hydrometer ??
> >
> >
>
>

PA scale is an indication of where you might end up. You still have to
calculate where you actually ended up when the fermentation is over.

Ray

"frederick ploegman" > wrote in message
...
> What is the purpose and function of the PA scale on my hydrometer ??
>
>

"Ray" > wrote in message m>...
> PA scale is an indication of where you might end up. You still have to
> calculate where you actually ended up when the fermentation is over.
>
> Ray
>
>

PA is Potential Alcohol, an estimate of the alochol content if all of
the sugar is consumed. If any sugar is left in the must, you will not
reach this potential.

Andy

I am very serious about this question. I can site references that state
differently that what you say. Can you give me accepted, published
references that agree with your statement?

Ray

"JEP" > wrote in message
om...
> "Ray" > wrote in message
m>...
> > PA scale is an indication of where you might end up. You still have to
> > calculate where you actually ended up when the fermentation is over.
> >
> > Ray
> >
> >
>
> PA is Potential Alcohol, an estimate of the alochol content if all of
> the sugar is consumed. If any sugar is left in the must, you will not
> reach this potential.
>
> Andy

"Ray" > wrote in message
. ..
> I am very serious about this question. I can site references that state
> differently that what you say. Can you give me accepted, published
> references that agree with your statement?
>
> Ray
>
> "JEP" > wrote in message
> om...
> > "Ray" > wrote in message
> m>...
> > > PA scale is an indication of where you might end up. You still have
to
> > > calculate where you actually ended up when the fermentation is over.
> > >
> > > Ray
> > >
> > >
> >
> > PA is Potential Alcohol, an estimate of the alochol content if all of
> > the sugar is consumed. If any sugar is left in the must, you will not
> > reach this potential.
> >
> > Andy

Ray & Andy,

One mole of sugar produces 2 moles of alcohol. The molecular weight of
sugar is 180 and the molecular weight of ethanol is 46. So theoretically,
180 grams of sugar can produce 92 grams of alcohol. 92 divided by 180 is
..511 or 51.1 percent.

But in practical fermentations, only 90 - 92 percent of the sugar produces
ethanol. The rest of the sugar produces higher alcohols, acetaldehyde,
succinic acid, etc.

In addition, some alcohol is blown off by the escaping carbon dioxide gas.

See Margalit, "Concepts in Wine Chemistry," page 56.

Regards,
lum

Thanks Lum but that is not what I am looking for. I know all that. I can
calculate the theoretical, maximum yield but I want the practical yield.
What I really am looking for is published raw data on beginning and ending
SG (or equivalent) and actual measured alcohol in the finished wine using a
laboratory determination rather than charts. I am embroiled in a dispute
with certain parties as a result of the article on determining alcohol that
I published in WineMaker. I have good references to accepted publications
that that state what the tables that are but I have not found raw data that
really verifies their tables and how they should be used. I have tried to
get this type of information from a number of laboratories that should have
it but have not been successful. (I am not willing to pay for it, that is
why I want published numbers.) If anyone can come up the this type of
information I would be really grateful.

Ray


"Lum" > wrote in message
...
>
> "Ray" > wrote in message
> . ..
> > I am very serious about this question. I can site references that state
> > differently that what you say. Can you give me accepted, published
> > references that agree with your statement?
> >
> > Ray
> >
> > "JEP" > wrote in message
> > om...
> > > "Ray" > wrote in message
> > m>...
> > > > PA scale is an indication of where you might end up. You still have
> to
> > > > calculate where you actually ended up when the fermentation is over.
> > > >
> > > > Ray
> > > >
> > > >
> > >
> > > PA is Potential Alcohol, an estimate of the alochol content if all of
> > > the sugar is consumed. If any sugar is left in the must, you will not
> > > reach this potential.
> > >
> > > Andy
>
> Ray & Andy,
>
> One mole of sugar produces 2 moles of alcohol. The molecular weight of
> sugar is 180 and the molecular weight of ethanol is 46. So theoretically,
> 180 grams of sugar can produce 92 grams of alcohol. 92 divided by 180 is
> .511 or 51.1 percent.
>
> But in practical fermentations, only 90 - 92 percent of the sugar produces
> ethanol. The rest of the sugar produces higher alcohols, acetaldehyde,
> succinic acid, etc.
>
> In addition, some alcohol is blown off by the escaping carbon dioxide gas.
>
> See Margalit, "Concepts in Wine Chemistry," page 56.
>
> Regards,
> lum
>
>

"Lum" > wrote in message >...
> Ray & Andy,
>
> One mole of sugar produces 2 moles of alcohol. The molecular weight of
> sugar is 180 and the molecular weight of ethanol is 46. So theoretically,
> 180 grams of sugar can produce 92 grams of alcohol. 92 divided by 180 is
> .511 or 51.1 percent.
>
> But in practical fermentations, only 90 - 92 percent of the sugar produces
> ethanol. The rest of the sugar produces higher alcohols, acetaldehyde,
> succinic acid, etc.
>
> In addition, some alcohol is blown off by the escaping carbon dioxide gas.
>
> See Margalit, "Concepts in Wine Chemistry," page 56.
>
> Regards,
> lum

Ar a recent talk, a professional winemaker here from BC mentioned that
they were getting higher alcohol levels for the starting Brix than
they used to, often by 1% or even more. She said this was confirmed by
other winemakers from the area. Her hypothesis was that the yeast were
getting more efficient in alcohol production. This could have large
repercussions if that were indeed the case. I'm wondering if this is
happening in other, hotter areas, as well?

Pp
Vancouver, Canada