I imagine the moon and sun do have an effect on gravity when it comes to
your hydrometer. Sure the wine is being pulled up making it less dense, but
at the same time the hydrometer itself is being pulled up, making it lighter
and more buoyant. The oceans combined is a very large body of water, so the
effects are easily noticed. The Great Lakes see tidal action too, but it's
minimal. Typical lakes don't see the effect since they are so small. A body
of water (or wine in this case) the size of your batch would be affected
only on a microscopic level. I'm not a scientist, but this sounds logical.

I live on the beach, on the beautiful BC coast. Is it better for me to rack
my wine at high tide or low tide?
Like to old wives tale about sauerkraut having to be made under a full moon,
should we be pitching our yeast during the waxing? The waning?
What would happen if you started a wine during an eclipse for goodness sake?
As I said, I'm NOT a scientist, LOL!



"OzWineKitz" > wrote in message
om...
> This is along the same lines as my previous post.
>
> Its a fact that the orbit of the moon varies up to say 5000km during a
> normal monthy (28day) orbit of the moon - right? The perigee and
> apogee, (vertical position in reference to the equator), also vary
> during a 27 day cycle.
> http://www.fourmilab.ch/earthview/pacalc.html
>
> Its also a fact that the Sun also has a gravitational influence on our
> liquids but it is 2 1/2 times less than the Moon.
>
> So if the moon can afect tides, by pulling water away from the earth
> due to gravitational influence, can it also affect our Hydrometer
> readings? Bear in mind that if the moon is pulling at our precious
> brew at the same force as the ocean, then our brew should be less
> dense right? If its less dense then our hydrometer will sink more,
> won't it? If so then we could be getting a false SG reading because
> the brew will appear a lower SG than it really is.
>
> Lets say it's a Full Moon at its perigee in Cairns - Australia on Dec
> 22nd 2003, (its also a high tide), and we take a Hydrometer reading at
> Sea Level with Pressure 1010mb - and it reads SG 0.992, then what will
> the SG read when the moon is at is apogee on Jan 3rd 2004, at sea
> level, with the same atmospheric pressure? Might it read higher?
>
> I can hear many say - WHO CARES? But the reality is this, with many
> wines I have measured the same SG but with noticably slight variations
> in sweetness when tasting - even though I am using the same juice and
> methodology for winemaking and the same hydrometer. Some might put it
> down to variations in the actual juice and differences in yeast colony
> count, etc...
>
> But could the relative local atmospheric pressure and Moon position
> influence the accuracy of my SG readings?
>
> Cheers,
> Steve!