# Calling all would be scientest



## seth8530 (Jun 15, 2013)

Ok guys, I need your help with something. 

First off most of us know the equation




to give a pretty good approximation of the your ABV is. However, since we do not know where the 131 in this equation comes from I will refer us to a different equation used by brewers. 

This equation uses a little bit of chemistry to justify where the where the constant comes from in front of the equation.




_"Where 1.05 is the number of grams of ethanol produced for every gram of CO2 produced, and .79 is the density of ethanol_"

The guaranteed problem with the latter equation is that it does not take into account the fact that your FG does not accurately reflect the sugar content of your your wine/beer/mead because the alcohol is throwing off the density of your must. I somehow doubt that the first equation takes this into account as well because any factor needed to correct this problem would need to be attached to the final gravity term. 

So, I am proposing a revised set of equations. That go to the form of this

ABV=131*(SG-FG*K)

Or the other Above equation where FG is always multiplied by a factor K.

The purpose and objective of "K" is to make your FG equal to what it would be if that FG was obtained by a pure water sugar mix. Pretty much, to get rid of the skewing caused by the alcohol. To do this I will need some data to find the proportionality constant "K" that relates the specific gravity of a mixture with just sugar and water in it to a mixture that has sugar water and a known amount of alcohol in it.

So the question is.. How do we find K? 


For that I will need some help from the community. I need people who have accurate metric scales that can get down to the gram in accuracy and people who have measuring equipment that is accurate to the ml. As well as accurate thermometers to make gravity corrections for temperature. These people will also need to have some dry 40% liqiour on hand and some table sugar.

I believe that this correction factor "K" is proportional to the alcohol concentration in the wine/mead/beer. 

And to obtain data I need at least three volunteers for consistencies sake. The experiment should not take more than a few hours but before I start writing up an experimental procedure I would really like to see what kind of internist there is in coming up with this correction factor.

So, if interested in helping me perform this experiment please give me a shout out!


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## DoctorCAD (Jun 15, 2013)

Kind of a waste, considering that a hydrometer is just not all that accurate, nor does it account for other "thickeners" in the wine.

Remember, SG is simply a measure of how thick a liquid is relative to water. That's all. And the resolution of a hydrometer is very poor and it is temperature dependant. Way too many variables for a "simple" k-factor.


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## seth8530 (Jun 15, 2013)

Dense is what you are looking for not thick. I believe that this can be accounted for with a factor and made more accurate yet not perfect. Whenever it is possible to remove error from an equation... why not do it? Also, the measurements that you read off of the hydrometer should be off no more than +-2 points where I believe that the alcohol in the wine will put you off more than that.


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## cmason1957 (Jun 15, 2013)

I have to jump in and ask, why bother? For me, just as long as I get somewhat of an idea what my ABV is, I am fine with. I ran through the math of your second equation, assuming a final SG of 0.996. It give you 133.4(SG - OG), that ends up being a 2% delta. Not enough to bother with.


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## seth8530 (Jun 15, 2013)

Mainly because why not. If you can do something better why not do it better? Also, when the alcohol content gets higher and higher the error will grow greater and greater.


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## BernardSmith (Jun 15, 2013)

But Seth , you seem to be discounting the reliability of SG readings. When we use a $5 or $6 hydrometer to gauge the SG, I suspect the reliability of our reading is pretty questionable. What tolerance are you assuming that a reading of 1.090 has or a reading of 0. 994. We are reading the height of a meniscus, typically through a plastic or glass cylinder at a height which may or may not be at eye level.


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## garymc (Jun 15, 2013)

I've thought about this and usually take into consideration this effect when I'm determining the alcohol content. I've developed a technique for it. I call it guessing.


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## GreginND (Jun 16, 2013)

There is no good way to determine how much other dissolves solids are affecting the density. It is not all sugar. The margin of error is going to probably be around 1% alcohol anyway. Trying to adjust fir the few tenths of a difference the alcohol density skews things in you final sg is pretty meaningless for your accuracy.

Remember, we're dealing with a fruit must with lots of stuff in it, not pure sugar water


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## seth8530 (Jun 16, 2013)

BernardSmith said:


> But Seth , you seem to be discounting the reliability of SG readings. When we use a $5 or $6 hydrometer to gauge the SG, I suspect the reliability of our reading is pretty questionable. What tolerance are you assuming that a reading of 1.090 has or a reading of 0. 994. We are reading the height of a meniscus, typically through a plastic or glass cylinder at a height which may or may not be at eye level.



I am not discounting the error from reading the hydrometer. I just think that the error from the alcohol in the wine is greater. I think a good assumed error for reading a hydrometer is +- .02 points. I suspect the alcohol has a greater impact than .02 points. However, like you are saying it is important to consider whether or not the error from your measurement is greater than what you can correct for. One thing I will do to test this out is take some sugar water up to 1.100 and then add alcohol into it untill it hits 20% ( and account for the dilution to sugar from volume of alcohol) and see what it does to the SG.



GreginND said:


> There is no good way to determine how much other dissolves solids are affecting the density. It is not all sugar. The margin of error is going to probably be around 1% alcohol anyway. Trying to adjust fir the few tenths of a difference the alcohol density skews things in you final sg is pretty meaningless for your accuracy.
> 
> Remember, we're dealing with a fruit must with lots of stuff in it, not pure sugar water



If you strain out the must that you should be able to get rid of most of the solids. I would imagine that the sugar makes up the overwhelming majority of the dissolved solids which you could use to argue that the dissolved solids are not significant. However, yes it is important to consider. I think I will run the above mentioned test first and see how big of a difference it makes before charging onward.


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## garymc (Jun 16, 2013)

I don't understand why you're starting with your sugar water at 1.100. I'd start it at a typical finished sweet wine point like 1.010 and add alcohol to a given percentage and then look at the difference, correcting for the additional volume. You're never going to have a wine that has that amount of sugar in it when it's done.


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## arcticsid (Jun 16, 2013)

let me get this straight Seth, if E=MC2, and I go all in with 3 aces and two kings and the only guy left has an ace in the pocket and I lose 40K, that makes the hydrometer reading exactly at 1.10, so there fore I bite the loss and in the end I still have a finish fermentation of .990, that gives me 40K less than I started and somewhere around 12%, or so.

If I would have started at around 1.20 and folded I would still have my money and somewhere down the line I would have a finished fermentation that should bring me somewhere close to 13.2%.

Doesnt matter, science says, most good whisky is around 80proof, I just looked at the side of the bottle, yep 40%.

So the formula is, if E=MC2, and I sart with a SG of 1.20, I will be shot by the time I get done with this bottle.

Therefore. Yep.

LMAO!


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## BernardSmith (Jun 16, 2013)

But Seth's question is a significant one for the science of wine making. Whether people find it a trivial issue to their wine making is a very different issue.


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## jamesngalveston (Jun 16, 2013)

In very general terms a wine fermentation occurs when yeast consumes sugar and converts it into approximately half alcohol and half CO2 gas (carbonation) by weight.

For example, if you had five gallons of juice that had 10 pounds worth of sugar in it, and you fermented all of that sugar with yeast, you would end up with 5 gallons of juice that has roughly 5 pounds of alcohol in it.

The other five pounds of sugar would dissipate into the air as CO2 (carbonic) gas. So in fact the five gallon batch would become five pounds lighter than it was before the fermentation started.

Realize that the breakdown of alcohol verses gas would not be exactly half and half, but usually it would be very close. Some variances do occur depending on external factors such as the amount of available air, nutrients as well as the type of yeast used. But, rest assured that it would be within 46% one way or another.

It is important to note here that the 10 pounds of sugar that was in the five gallon batch may not have come all from sugar you added, but partially from the fruit as well. And in some cases, such as when making a wine from grapes, there may be no sugar required at all. In these cases enough sugar is already in the fruit itself to produce a wine with 11 or 12 percent alcohol.


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## seth8530 (Jun 16, 2013)

garymc said:


> I don't understand why you're starting with your sugar water at 1.100. I'd start it at a typical finished sweet wine point like 1.010 and add alcohol to a given percentage and then look at the difference, correcting for the additional volume. You're never going to have a wine that has that amount of sugar in it when it's done.



No real reason for me wanting to start out at 1.100 rather than say 1.01 besides the fact that it is a nice round number. I am just wanting to see how much it shifts the gravity at this point. However, 1.01 is just as good as 1.1 at this stage.




arcticsid said:


> let me get this straight Seth, if E=MC2, and I go all in with 3 aces and two kings and the only guy left has an ace in the pocket and I lose 40K, that makes the hydrometer reading exactly at 1.10, so there fore I bite the loss and in the end I still have a finish fermentation of .990, that gives me 40K less than I started and somewhere around 12%, or so.
> 
> If I would have started at around 1.20 and folded I would still have my money and somewhere down the line I would have a finished fermentation that should bring me somewhere close to 13.2%.
> 
> ...



You forgot to factor in the square root of pi! All wrong, do it over!



BernardSmith said:


> But Seth's question is a significant one for the science of wine making. Whether people find it a trivial issue to their wine making is a very different issue.



Woot! some support!



jamesngalveston said:


> In very general terms a wine fermentation occurs when yeast consumes sugar and converts it into approximately half alcohol and half CO2 gas (carbonation) by weight.
> 
> For example, if you had five gallons of juice that had 10 pounds worth of sugar in it, and you fermented all of that sugar with yeast, you would end up with 5 gallons of juice that has roughly 5 pounds of alcohol in it.
> 
> ...



I could see your idea leading to a very interesting way of coming up with the final ABV by taking the change in mass and then relating that to the chemistry. However, the only problem is that it is really hard to tell how much Co2 left the wine and how much of it is just hanging around inside of the wine. I imagine even a perfectly degassed wine still has a good bit of Co2 still stuck in it. Some if will also dissolve to form acids.. But, very interesting idea you got there.


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## JohnT (Jun 17, 2013)

Why not simply purchase an ebulliometer and be done with it?


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## seth8530 (Jun 17, 2013)

Because ebuillometers are not cheap and what good would it do all the other people with out an ebuillometer?


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## jamesngalveston (Jun 17, 2013)

Well...seth you are brilliant no doubt,, but i will take the course that dessertmaker does,,,,I HATE MATH....if its not dollars and cents....i dont do it.
good luck


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## Stressbaby (Jun 17, 2013)

I think this is great and if I had a few hours I would volunteer.


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## seth8530 (Jun 17, 2013)

I got a small task you could do. Should not take more than 20 minutes. Wana give it a go?


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## Runningwolf (Jun 17, 2013)

JohnT said:


> Why not simply purchase an ebulliometer and be done with it?



Still waiting for mine!


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## Stressbaby (Jun 17, 2013)

seth8530 said:


> I got a small task you could do. Should not take more than 20 minutes. Wana give it a go?



Sure if you don't have a deadline.


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## seth8530 (Jun 17, 2013)

I feel like the best way moving forward is for one of us to take 100 ml of water. Add 3 grams of sugar to it. ( should give you 1.010) Then add 60 ml of 40% abv spirit to give you a solution at 15% abv. This will give you a total volume of 160ml. which give you 3 grams of sugar per .160 liters.

This is the same as 18.75 grams of sugar per liter.

Which if you look at this chart http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm

Should put you right at 1.005 or more precisely 1.00561 if you were to perform a linear interpolation on that chart.


If you wonder how I got my numbers


I set

.15=W*.4/(100+W) Where W is the volume of spirit needed, .4 is the abv of the spirit, (100+W) is the volume of the spirit and sugar water and .15 is the wanted abv.

Now what we would be looking for is how far below 1.005 does the spirit put the mixture at. If it is extremely close then this whole issue is no big deal. If it is off by a larger certain percentage, then things are more interesting. I do not have a 

 hydrometer or scale handy so I cant perform this experiment.

Make sure to make temperature corrections to the hydrometer!

Thanks a ton!


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## DoctorCAD (Jun 18, 2013)

I think the best "test" method would be to take pure RO and distilled water, an exact amount, and add pure and filtered alcohol until you have the mix you are looking for, say 13%.

Take an exact amount of that solution and weigh it (and I'm talking a Mettler balance or other high-end system) accurate to 4 decimal places. Take the same amount of wine, known to be 13% and weigh that as well. The difference would be the weight of all of the TDS. 

Those solids are what makes your experiment difficult, if not impossible, because (I'm guessing) every wine type would have a different amount of those solids. The solids help "float" the hydrometer, causing ABV calculations to be off.

All of your calculations and experiments are basing the outcomes on "clear" liquids and wine is not clear.


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## JohnT (Jun 18, 2013)

I have a better idea. Forget APV. 

.01% apv has almost no effect on the human body. Products can have "alcohol free" on the label, and still have a level of .01 apv. 

I say that we measure the FF (aka "the Fershnickered Factor"). 

This is the number of glasses (with respect to time) that it takes to get "faced".


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## cmason1957 (Jun 18, 2013)

I stumbled across some interesting pages about this subject (searching for something else). This one gives five different formulas to calculate the Potential Alcohol. With a note that one of them seems to give close ebulliscope: http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm (this may have been posted earlier).

This one is posted on a Beer making site, but says the more complicated formula seems to provide greater accuracy at the higher gravities used for wine making:
http://www.brewersfriend.com/2011/06/16/alcohol-by-volume-calculator-updated/

The more complicated formula is AVB = (76.08*(SG-FG)/(1.775-SG)) * (fg/0.794)
http://www.brewersfriend.com/2011/06/16/alcohol-by-volume-calculator-updated/


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## FABulousWines (Jun 18, 2013)

I agree with John. If I can get an estimate close to 0.5% that is good enough for home wine making/drinking. All I really care about is keeping the ABV between 10% and 13%. Hot enough to remain stable, but not so hot that it overwhelms the taste.

But, Seth, I do admire your efforts. I wish more of my employees had your work ethic!


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## Flugel91_30 (Jun 18, 2013)

Well, technically speaking, the second equation's value (1.05/.79) is the K value you are looking for. This constant essentially tries to relate the volume of alcohol in the mixture to its density, adjusting the variables (specific gravity) appropriately. Other than relating alcohol to CO2 (I see the connection, I just don't see why they're using it in this equation because after degassing, density should be irrespective of CO2 produced), I think this is a fairly good value to use. However, if I were you, I wouldn't use "K," as in chemistry "K" most often stands for Kelvin or, in the lower case, a rate or equilibrium constant for a chemical reaction. Just my 2 cents there, though.

Essentially, the value (SG-FG)/FG relates the change in specific gravity, or density relative to water, as a decimal percentage. Multiplying by 100 turns this into a more familiar percent change value (percentage). This equation uses density, however, and not molarity or some other total mass measurement, and so can only really approximate the total sugar and thus % abv. 

An equation using degrees Brix would hypothetically be more accurate, as this is a % by weight measure. Say, for instance, you have 5 gallons of must, pre-ferment, at 22.5 degrees brix. Since 1 degree Brix is 1 gram of sucrose per 100 grams of water, you have 22.5 grams of sucrose, or roughly 45 grams of glucose (1 sucrose = 2 glucose dimerized), per 100 grams of water. We have 5 gallons of must, and since 1 gallon=3.785 Liters = 3785 grams of water, we have a total sugar mass of ((22.5g/100g) x 3785g) x 5 = 4258 g sucrose, or 9.38 pounds of sucrose. This is, in turn, equal to 12.44 moles of sucrose. 

If we proceed to a FG of 1.000, with a degrees brix of 0.0, then all 12.44 moles of sucrose have, hypothetically, become CO2 and Ethanol. Since 1 mole of sucrose yields 4 moles of ethanol, we should now have 49.8 moles of ethanol. This is a molarity of 2.63 M, or 2.63 moles of ethanol per liter of solution. 2.63 moles of ethanol equals 121.g ethanol, which again is per 1L water or 1000g water, giving a percent by mass of 12.11%. To get % abv, you would have to convert this value, which I honestly do not know how to do. One would need to know the volume of the solution, which can really only be determined accurately by measuring.

I wouldn't consider this authoritative by any means. It's really just me tinkering with things stoichiometrically. I'm not a professional chemist, but have studied chemistry in college. Still, again don't consider this definitive. I'm sure I've made an error somewhere... This answer is fairly close, however, to the % abv you would get following the scales on a triple scale hydrometer (12.11% as opposed to 12.9%). This difference should be accounted for when converting to % by volume, though. I would honestly argue that % by mass is a better measure than % by volume, as % by mass doesn't change with temperature. Of course, you probably aren't serving wine in/at wildly fluctuating temperatures... 

Anyway... that's a lot of calculations, enough to warrant my stopping for a while lol. As I've state elsewhere, I'm pretty new to wine-making. I do, however, know a little about chemistry...


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## Flugel91_30 (Jun 18, 2013)

> I feel like the best way moving forward is for one of us to take 100 ml of water. Add 3 grams of sugar to it. ( should give you 1.010) Then add 60 ml of 40% abv spirit to give you a solution at 15% abv. This will give you a total volume of 160ml. which give you 3 grams of sugar per .160 liters.



This wouldn't provide 160 mL of solution, as adding solute and solvent produces a volume of solution that is actually less than that of the sum of the two volumes. This is because the solute, in a sense, 'meshes' with the solution. In other words, the solute molecules are interspersed in between the solvent molecules. It's kind of like pouring marbles into a ball pit; the marbles make up for a measurable increase in volume, but some fill the empty spaces between the balls and thus do not add to the total volume.


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## Runningwolf (Jun 18, 2013)

Whoooa you guys are like a good mysterious wine. Who know's whats in it but is sure is good. I have no idea what the He!l you guys are saying but I'm impressed! I can't even think of any BS to give you this time.


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## seth8530 (Jun 18, 2013)

cmason1957 said:


> I stumbled across some interesting pages about this subject (searching for something else). This one gives five different formulas to calculate the Potential Alcohol. With a note that one of them seems to give close ebulliscope: http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm (this may have been posted earlier).
> 
> This one is posted on a Beer making site, but says the more complicated formula seems to provide greater accuracy at the higher gravities used for wine making:
> http://www.brewersfriend.com/2011/06/16/alcohol-by-volume-calculator-updated/
> ...



Thanks for the equations, I will give them a look!



Flugel91_30 said:


> Well, technically speaking, the second equation's value (1.05/.79) is the K value you are looking for. This constant essentially tries to relate the volume of alcohol in the mixture to its density, adjusting the variables (specific gravity) appropriately. Other than relating alcohol to CO2 (I see the connection, I just don't see why they're using it in this equation because after degassing, density should be irrespective of CO2 produced), I think this is a fairly good value to use. However, if I were you, I wouldn't use "K," as in chemistry "K" most often stands for Kelvin or, in the lower case, a rate or equilibrium constant for a chemical reaction. Just my 2 cents there, though.
> 
> Essentially, the value (SG-FG)/FG relates the change in specific gravity, or density relative to water, as a decimal percentage. Multiplying by 100 turns this into a more familiar percent change value (percentage). This equation uses density, however, and not molarity or some other total mass measurement, and so can only really approximate the total sugar and thus % abv.
> 
> ...



I disagree with K being a bad constant since it is used in many other things other than chemistry ( about 15 million things in engineering) but that does not matter.. I do think that the equatin that is givin is not quite right because the units do not seem logical to me.

The important thing is that I agree with you, going through this in a stochiometric manner is the best way to do it. However, the whole reason why I care so much about getting the proper ending residual sugar is so that I can accurately apply the stoch to create a formula that uses this ending residual sugar that we are trying to create a SG correction for. So, I think we are on the same general train of thought.



Flugel91_30 said:


> This wouldn't provide 160 mL of solution, as adding solute and solvent produces a volume of solution that is actually less than that of the sum of the two volumes. This is because the solute, in a sense, 'meshes' with the solution. In other words, the solute molecules are interspersed in between the solvent molecules. It's kind of like pouring marbles into a ball pit; the marbles make up for a measurable increase in volume, but some fill the empty spaces between the balls and thus do not add to the total volume.



This is true, I was surprised when I found this out. However, I should not of been. Conservation of mass is a fact, conservation of volume is not. However, I think it is irrelevant for this test I am want performed because I am only looking for how badly the alcohol will affect the reading on the hydrometer.

Good thought tho!


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## DoctorCAD (Jun 18, 2013)

Seth, flugel was not saying not to use a constant, rather he was referring to K vs. k.

Big K = degrees kelvin
small k = constant


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## seth8530 (Jun 18, 2013)

That is not the way I interpreted what he said. The way, I saw it he was disputing my use of that variable name because of possible confusion. However, like I said earlier names of variables are moot points. K, k, ,Ll, Allababba Wallakazoo, all fit just as fine so long as they are defined before hand.


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## spaniel (Jun 18, 2013)

Interesting discussion.

Being a trained (although not practicing) scientist....cell and molecular biology, a handy education to transition into winemaking...I really try not to apply such rigor to a hobby. I go by the difference on the hydrometer, and declare it "close enough".

To determine the error, I would do the following. Say we are targeting a semi-sweet wine with a final SG of 1.010. So measure a sample of sugar water that reads 1.010...knowing the exact weight of sugar contained in that sample (start with distilled water, add sugar in weighed increments). Now, create a sample of equal volume with known ABV, containing the same weight of sugar. What is the difference in the SG reading? There is your error. Run the experiment and tell me the answer.

Now, this does not answer the question of the influence of other dissolved solids, which is a real concern. But from an academic standpoint it would isolate the error introduced by the alcohol. Truly, I am interested in the answer.


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## seth8530 (Jun 19, 2013)

spaniel said:


> Interesting discussion.
> 
> Being a trained (although not practicing) scientist....cell and molecular biology, a handy education to transition into winemaking...I really try not to apply such rigor to a hobby. I go by the difference on the hydrometer, and declare it "close enough".
> 
> ...



That is pretty much what I was shooting for. However, I like your method! It is simple!


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## Midwest Vintner (Jun 20, 2013)

You won't ever be that close with a hydrometer. It is not just solids (which will increase during fermentation if you are using any such as skins, etc), but also other fermentable solids that may or may not be in the sample or be turned into alcohol. For me, .5% abv is not going to change a whole lot. A huge part of the wine making process is knowing your taste buds, IMHO.


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## seth8530 (Jun 20, 2013)

Midwest Vintner said:


> You won't ever be that close with a hydrometer. It is not just solids (which will increase during fermentation if you are using any such as skins, etc), but also other fermentable solids that may or may not be in the sample or be turned into alcohol. For me, .5% abv is not going to change a whole lot. A huge part of the wine making process is knowing your taste buds, IMHO.



The issue is that we might be off more than .5%. We could be off my 2% for all we know (prob not that bad) but who knows? The goal I have is to create a physics driven ABV equation for us to use. I agree, it will not be perfect but I want us to do better and not perfect.


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## BernardSmith (Jun 20, 2013)

@Seth, This discussion of accuracy (and reliability) is interesting. I may be wrong - (Ha! I often am) but I believe that the tolerance in law for a stated ABV is plus or minus 1.5 %, so a commercial winery claiming that their wine is 12.5% ABV might legally have produced a wine closer to 11 % or as high as 14 (http://blog.wblakegray.com/2013/05/note-to-wineries-label-alcohol.html) ... In other words, for practical purposes , the law allows a range of 3 percent


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## seth8530 (Jun 20, 2013)

Thanks! You are correct that their is a legally given tolerance. I think the allowed error in TN is +- 1 percent abv.


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## seth8530 (Jun 25, 2013)

Thanks everyone for the input! I have decided that for the new ABV equation it will most likely be best to first solve it in terms of mass of alcohol. This will help us out because chemical reactions are done in terms of mass not volume. 

If we can find out a residual sugar correction for a hydrometer we can use that to determine the amount of sugar that was consumed in the chemical reaction and thus get the mass of alcohol in the solution. Once that has been done we can use an equation that I managed to derive today that will take us from mass of alcohol into ABV. 

Please, I am asking anyone who can to look over my math to make sure it looks good. I have been known to make mistakes from time to time. 

So items that we need to make this work

- A correction factor that relates the final gravity to the actual sugar content of the wine

- An equation that relates the change in sugar to the mass of alcohol created in the wine.

If we can get these we will have a physics based ABV equation.

PLEASE EXCUSE MY HANDWRITING! 

View attachment Derivation of ABW to ABV.pdf


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## cmason1957 (Jun 26, 2013)

The math seems to be straight-forward enough algebra.

The items which need work seem to be the big problem here. 

I was worried, when I first read your post that there might be real math in there. I was almost expecting differentials or integrals, or at least a summation.


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## seth8530 (Jun 26, 2013)

cmason1957 said:


> The math seems to be straight-forward enough algebra.
> 
> The items which need work seem to be the big problem here.
> 
> I was worried, when I first read your post that there might be real math in there. I was almost expecting differentials or integrals, or at least a summation.



Nahh, no need for any of that right here. If we were tracking the rate of change of the sugar drop then we might start getting into some calculus, but their is a lot of very good things you can do with some rather pedestrian math skills as long as you think as math as a language and a tool.


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## seth8530 (Jul 1, 2013)

Ok, I have an update. I have managed to derive the next part of my ABV equation. The only thing that we are now missing is a correction factor on the ending brix to make up for the alcohol throwing off the measurement. Once this is done I believe that we will have an ABV equation that is based heavily on physics and chemistry instead of being data driven. Please give the attached PDF a look over. I have detialed the proccess I took to get my equation and shown every step along the way. 

As of right now my equation tends to give results that are nearly 1% higher in abv than most of the existent equations, but with some work I am sure we can come up with the final brix factor to give us something a little bit better. 

View attachment Seth's ABV Equation NO correction factor.pdf


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## seth8530 (Jul 10, 2013)

I have a potential solution. I managed to find an equation that emperically relate thetrue final brix to the change in brix.


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## seth8530 (Jul 20, 2013)

Ok, I am posting my approximation. I used an empirical relationship that relates the measured brix to the actual brix taking into account the alcohol shift. This is NOT perfect, however, I do believe it is rather good and is as good as if not better than the existing equations. The next step will be to make that FG non empirical and make it physics based.

Anyways long story short... 

.53055*FG*(BrixI-BrixF)=ABV is my equation. I am attaching the current derivations as well in PDF form. 

View attachment My_abv_equation_mk1.zip


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## barryjo (Jul 28, 2013)

seth8530 said:


> Mainly because why not. If you can do something better why not do it better? Also, when the alcohol content gets higher and higher the error will grow greater and greater.


 
If you want better, you could always invest in an ebulliometer. And I do mean Invest.
Personally, i prefer the Honneyman method. I run that while bottling. 
Naturally the accuracy of anything depends on the test equipment used. And on the operator using it. 
But for most winemaking, and especially when ingredients are added after fermentation stops, Honneyman works for me.


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## manvsvine (Jul 28, 2014)

different yeasts have different levels of efficiencies at converting sugar into alcohol.
yeasts that have higher alcohol tolerances also tend to be more efficient at converting sugar into alcohol, where as other yeasts convert sugar into higher percentages of co2 . before you can come up with an accurate formula , you need to know what the co2/alcohol split is for what ever yeast you use. you can get a 1% alcohol difference between different yeasts at the same sugar level in the must. before you can calculate potential alcohol you need to know the efficiency quotient of the yeast. unfortunately for us its easier to work backwords , ie you know what your final alcohol level is from testing the finished wine and what your starting brix was so you can calculate the efficiency quotient of the yeast you just used. 
but that would only be valid for that must as any other must has nutrient and temperature variables .

distillers making brandy seek out the most efficient yeasts possible , where as making dessert wine they seek out the least efficient and alcohol tolerance yeasts.

even lallemand could not come up with reliably accurate formula.

http://wineindustrynetwork.com/uploads/tips/gqRwa10bvFXsGDBIHfLKmE7A9yjiCt.pdf


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