"Joe Sallustio" > wrote in message
om...
> Just an FYI...
>
> I did a little experiment with cheap tequila yesterday. I filled a
> 250 ml graduate with a 10% solution of alcohol.
>
> (62.5 ml 40% ABV tequila, topped to 250 ml of solute with distilled
> water.)
>
> @ 77 F = 250 ml
> @ 24 F = 249 ml
>
> That should have worked out to a 76 ml drop in both carboys of red I
> have in stabilization; 18.9 L/ .25 L = 76 ml. It did. Both took a
> bit over 70 ml, (74 and 76). (I did not mark them exactly when I
> chilled them and do not know the exact temperature of the wine prior
> to stabilization. I did not expect to do this experiment.)
>
> That works out to a change of 0.0755 ml/L/degree F.
>
> In a 5 gallon carboy that would work out to an increase of 1.4
> ml/degree F rise.
>
> Water and alcohol densities are not a constant but for all intents and
> purposes it's close enough over the sort range of temperatures
> winemakers work with.
>
> Joe
>
Not a bad experiment at all and not bat results considering the accuracy of
the measurements and the range of temperature. Here is another approach:

Coefficient of expansion of Water @ 21 deg. C (70 deg F.) is 0.00021
Coefficient of expansion of Methanol (temp not given so STP assumed) is
0.00122

IF you can combine these properties linearly (a big if if someone wants to
correct me) then the Coefficient of expansion of 14% wine will be 0.00034.

Now a 6 gal batch will be 22714 ml so the expansion with 1 deg C temp change
would be 7.75 ml. or for 1 deg F temp change would be 4.31 ml. For a 5 deg
change in your den this would be a whooping 21.5 ml. Now how much rise in
fluid level that translates to in your carboy depends on how high up into
the neck the carboy is filled and the inside diameter of the neck.neck.

Now these figures are for temperature changes around room temperature.
Water coef. of expansion drops drastically at lower temperatures and
methanol coef of expansion probably does as well. Note that the coef of
expansion of water reverses itself below 39 deg F. So over the large change
in temperature you used you would probably get a lower value than is
observed at near room temperature. In fact you got 0.075 ml/l-deg F average
over the range of 77 to 24 deg F. while it get 0.34 ml/l-deg F at
temperatures near 70 deg F. Since most of us do not store our wine at
temperatures that low, the numbers for 70 deg. F are probably more
serviceable.

Does anyone know of any measurements on water methanol mixtures?

Ray