Hello Fernando;
fernando_romagnoli said:
Looks like you got pissed; I am sorry I am just trying to share and gain knowledge here.
No. Why would I be pissed?
I’m just trying to understand your premise. I’m also sharing knowledge.
One question: Is your spreadsheet something you're actively using and getting reliable results from?
I am so sorry to disappoint you, but as a mechanical engineer I have to say that GAS LAW IS CHEMISTRY, chemistry is not only about chemical reaction.
I hear you. Thanks for that reference point. I have solid credentials, too. 8)
Since molecules are involved, I suppose it can be considered chemistry. However, gas law is about the movement and pressure of molecules with relation to volume and temperature. The application of gas law doesn’t require knowing the form of the molecule.
Avagardo’s law states that 1 mole of any gas will occupy the same volume as any other gas at 1 atmosphere. Charles’ law tells us that the volume relationship will follow temperature. Boyles’ law tells us that as volume increases, pressure decreases. These three simple laws are the basis of ideal gas law.
Your source:
http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/Gas_Laws
Confirms it.
To be clear, I’m referring to the interaction between the beer and dissolved CO2, not how the CO2 is generated. The generation of CO2 from sugar is indeed a biochemical process with differing efficiencies due to the form of the sugar used. What we’re discussing is controlling the production of CO2 so that the sum of two sources equals an appropriate carbonation level.
To discuss the chemistry, we have to discuss the sugar source, which isn’t what I was addressing.
I never told you do not understand what is behind I just told that the BYO article specifically states that the maximum temperature must be used.
Ok. So, the assumption must be the
minimum resident CO2 is the foundation for carbonation? No other variables?
The same equation does not mean the same constants inside the equation, the residual CO2 equation constant is different for all the sources but very similar results are obtained no matter the source you are following.
Correct. They all are making the same assumption of resident CO2 based on resting beer at or above fermentation temperature. This assumes that no nucleation by racking, dry hopping or agitation has occurred to reduce the assumed level. That’s cool, because it makes the assumption of needed sugar much simpler.
A sugar gravity of 1.002 is roughly equal to 1 atmosphere of potential CO2 at 20oC. Most sugar dosing calculations are assuming some CO2, which is the premise of the BYO article. Nearly universally, sugar dosing calculations of any kind results in a gravity rise of 1.004, or 2 atmospheres (volumes).
“…Most of the time/temperature charts assume 0.77 volumes of static CO2 before carbonation. Similarly, sugar dosing assumes residual carbonation, too…”
I disagree, the residual CO2 can go from 1.21 volumes at 8.33 C or 47 F to .655 at 28.33 C or 83 F, read the BYO article, the namogram from John Palmer and the BeerSmith Carbonation tool.
Maybe my fault for changing the subject a little. I was referring to time temperature charts of forced carbonation. Again, on the mechanical side. However, those numbers follow the same assumptions found in universal gas law and are about how much CO2 will
laminate (meaning how molecules occupy space together). The CO2 is already produced, so its capture isn’t about the chemistry, rather about the mechanical balance found in universal gas law.
“…. Your spreadsheet is a statistics buffet”
I agree it is a mess, It is a spreadsheet prepared by me for me I will clean it and upload a new version with an improved interface.
Cool. That’ll help me understand how you’re trying to accomplish your goal.
“…Ultimately, there seems to be a chart that makes the argument that BeerSmith overdoses sugar based on your residual CO2 assumptions and a constant of unknown origin (109%?)…”
I use cane sugar, If you open your beersmith table sugar carbonation profile than you will see the priming effectiveness factor is 109% in other words the cane sugar is more effective than corn sugar since the original chart is for corn sugar.
Ah! Ok. But you also mention invert sugar, which is a changed state of sucrose where glucose and fructose are the result. The change can be induced by heat, enzyme or weak acid (typically citric). So, I’m curious, are you using raw sucrose? Or changing it to invert? Or is invert sugar sold (somewhat incorrectly) as sucrose in your country?
Dextrose & glucose can be metabolized without any loss of energy because they enter the glycolysis pathway unchanged. Although both glucose and fructose have the same molecular formula, C6H12O6, but the difference is in the arrangement of Hydrogen and Oxygen. Fructose has to be altered first (an expense of cellular energy) before it can enter the glycolysis chain to create the requisite 2 each CO2 and ethanol. So, glucose/dextrose is more efficient at creating carbonation, explaining the 109% conversion factor.
Finally don’t you have any opinion about a future tool to calculate the inverted sugar to be shot with a syringe?
No, not at all. It sounds like you’re dosing each bottle, but I’m guessing based on your description. Bottle dosing is hard to keep accurate. Bulk dosing is far more consistent and controllable. How did you arrive at the need to dose with a syringe?
