Volume Temperatures

[bwestfall03]

Hey guys,

I am going through some troubleshooting on an issue that has risen up and I am looking at my volumes. Does anyone know what temperatures the estimates in BS3 are at?

For instance is the pre-boil volume measured at 212F or 200F or 60F?

Looking for pre-boil and post-boil volume temp.

[Oginme]

BeerSmith applies your thermal expansion to all volumes which are measured 'hot'.  So if you have the default 4% thermal expansion, this 4% is applied to your strike volume, pre-boil volume, and the estimated post boil volume.  The program does NOT scale the volume based upon temperature.  Given this, for a thermal expansion of 4% your most accurate measurements for the above mentioned points to correspond to the program estimates would be taken right at boiling.

Cold volumes which are estimated and measured are your volume into the fermenter and trub and chiller loss.

[bwestfall03]

So if I have an estimate from BS3 for a pre-boil volume of 12 gallons that measurement would be for a temperature of 212F?

[Oginme]

If your thermal expansion coefficient in your equipment profile is set to 4%, then the answer is yes.

[mayzerbrau]

I created a spreadsheet to help me understand this a few years ago.  On a 5 gal batch the thermal expansion has a minor impact on volume (about 1 qt) and about 2 points on Specific Gravity (SG).  On larger batches like 1 bbl and up it can have a significant impact on volume as it can change by gallons!  I believe BS assumes you are measuring your strike water hot and everything stays hot until you hit the fermenter.  This is where BS applies the thermal expansion (shrinkage).  It reduces the volume and increases the SG.  I measure strike water cold and measure through the process.  If I used the same measurement stick for each part of the process I would need to adjust the by thermal expansion. Instead I created measurement sticks for the correct temp range.  I have one each for 70F, 150F, and 210F.  I then set the thermal expansion in BS to 0.  HOWEVER this will affect you SG estimation by 2-3 points.  I set it to 0 the get volumes and I will toggle the thermal expansion back to 4 to see the predicted SG.  BTW the expansion from 70 to 150 is 2% and between 150 and 210 is 2%.   4% total from boil to fermentation temps.  See chart.  Another interesting thing is that Plato is not affected by thermal expansion.  Specific gravity is a density measure (weight/volume) where as Plato is a weight/weight ratio. The weight (mass) of water does not change as it is heated.

Temp F?   ft3/lb
40             0.01602
60             0.01603
70             0.01605
150           0.01634
170           0.01645
180           0.01651
210           0.01670

[GigaFemto]

You are correct that the temperature affects the density (SG) of the water and wort. However, you don't really measure the density at the high temperatures. For a hydrometer, you need to cool your sample down to the calibrated range. For a refractometer the drop of wort cools down when it contacts the instrument. That means that all SG measurements are made at cool temps, so the decrease in density at high temps does not affect the readings.

--GF

[mayzerbrau]

Correct! It wont really affect actual readings but it does affect the predicted gravity in BS.  You can see this in a recipe or the boil off tool.  Change the cooling shrinkage % and you will see the estimated gravity change.