Calling all would be scientest

[seth8530]

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!

 

[DoctorCAD]

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.

 

[seth8530]

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.

 

[cmason1957]

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.

 

[seth8530]

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.

 

[BernardSmith]

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.

 

[garymc]

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.

 

[GreginND]

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

 

[seth8530]

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.

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.

 

[garymc]

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.

 

[arcticsid]

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!

 

[BernardSmith]

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.

 

[jamesngalveston]

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.

 

[seth8530]

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.

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!

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

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!

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.

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.

 

[JohnT]

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

 

[seth8530]

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

 

[jamesngalveston]

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

 

[Stressbaby]

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

 

[seth8530]

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

 

[Runningwolf]

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

Still waiting for mine!