Alcohol Content

I know this one gets debated a lot and don't want to start an argument but was trying to work out the alcohol content of my latest concoction.
I started with SG 1.092 giving PA of 12.5%.
Finished at 0.984.
So, do I have a 12.5% abv wine or do I use the total drop of SG giving 14.5%?
This is only for the label on the bottle for when I give a couple of bottles away. Main thing is even before any aging it tastes great! Definitely my best batch yet.
Reply to
"R-D-C" Royal De-Canter? wrote (in part):
Please explain the 14.5% computation.
Please explain the 12.1% computation.
Dick -- Richard D. Adams, CPA Moderator: misc.taxes.moderated
Reply to
Dick Adams
Go to
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and you can find a formula that works for me. To get me in the ball park I just subtract finished SG from the beginning SG, for get the decimels and devide by 7. That is close enough for me. Using my rounding system your alcohol level would be 15.4%. Useing the correct ffigures it would be 108/7.04 = 15.3409.Aubrey
Reply to
"R-D-C" Royal De-Canter? wrote (in part):
Dick - This has been discussed a lot recently. Here's the formula I use; Reference: Homebrewing, Volume 1 by Al Korzonas Page 31
Calculation of alcohol by weight; % ABW = (OG - FG) x 105
Calculation of alcohol by volume; % ABV = ABW x 1.25
Combined method for alcohol by volume; % ABV = (OG - FG) x 131.25
OG refers to original specific gravity. FG refers to final gravity or the specific gravity when fermentation is complete. It's my belief that you can't ferment more sugar than is in the wine to begin with. So, the FG should be considered 1.000. The fact that we observe specific gravities less than 1.000 is because of the presence of alcohol and the way it effects the hydrometer. Therefore, when I calculate alcohol content I always use a FG of 1.000.
In R-D-C's case; %ABW = (1.092-1.000) x 105 or 9.66% %ABV = 9.66 x 1.25 = 12.075 or 12.1%
Bill Frazier Olathe, Kansas USA
Reply to
William Frazier
I will put 12% on my label then.
At least that is enough alcohol to ensure it will keep.
Reply to
Got back to find so many posts that I decided to reset my reader and get a fresh start. Senior moment (don't ever get old) 'cause now I can't find the threads I was watching. Will do my best to answer those I can find.
You have about 12.2%ABV in that wine. However, with an end reading of 0.984, I would *guess* that this is a "Country" (non-grape) wine and that there *may* not be enough acid in it. If this wine were mine, I would re-check the pH immediately. If I found that it was higher than ~3.5, (ie 4.0) I would adjust_both_acid and SO2 to achieve an "aseptic" level of molecular SO2. If my *guess* turned out to be wrong, at least I would be satisfied that my wine would "keep". HTH
PS - Let me add this in here. About all that most "modern" winemakers do is hammer all their ferments down to as close to bone dry as they can get them and either leave them that way or stabilize chemically and re-sweeten later. For these folks there is no *need* for end alcohol calculation since the original PA already tells you how much alcohol will be in that wine _if_ and _when_ the wine goes DRY !! (eg when all of the sugar is consumed). So - for all of these folks, all they have to do is use the original PA number for their "end alcohol" value and print that on the label. (assuming there have been no subsequent dilutions) This stuff is *REALLY* easy if you will just let it be. This works because this is exactly what our hydrometers are designed to do for _practical_ winemakers !!
The only time alcohol (and RS) calculations are_needed_is when a ferment _doesn't_go dry. (eg for RS ferments and/or "stuck" wines) Even for "stuck" wines, this isn't really necessary if the maker is determined to re-start the ferment and hammer it the rest of the way down to dry. About the only thing it tells him is whether a re-start is feasible or not.
Which pretty much leaves us with only "old fashioned" RS ferments to worry about. So - for all those who only do "modern" ferments, forget about all this foolishness and just use the PA number to print on the labels of your *DRY* wines !! Of course, for wines that are fermented dry and then re-sweetened, subsequent dilutions will have to be calculated. HTH and HTMS
Reply to
frederick ploegman

This is the wrong answer. It is the result of using total drop without compensating for the effect of the alcohol on our SG readings. It's like our computers: Sh** in - sh** out. HTH
Reply to
frederick ploegman
Hi Bill
Neither of these methods work. As you have already indicated, the Korzonas method doesn't compensate for the effect of the alcohol on total drop. And - your method of substituting 1.000 for any and all FG readings simply ignores the fact that there is a_big_difference between an FG of say 0.984 and say 0.995. In fact, all your method does is recalculate the original PA value. Do some "sanity checks"and you will see this is true.
Of course, if the wine goes dry, this will be the correct answer, BUT_only_ if the wine goes *dry* !! This being the case, why bother with a calculation at all when all we have to do is use the original PA as our end alcohol value for *DRY* wines ?? HTMS
Reply to
frederick ploegman

Nope, this is the old CJJ Berry formula and it doesn't work because it fails to compensate for the effect of alcohol on total drop. HTH
Reply to
frederick ploegman

Nope. Your reference got it wrong so now you have it wrong. Authors are not infallible. Be careful what you choose for a reference. HTH
Reply to
frederick ploegman
"...the Korzonas method doesn't compensate for the effect of the alcohol on
Frederick - I only have narrow range hydrometers. They don't have a PA scale so Korzonas method and a FG of 1.000 gives me a reasonable number.
Bill Frazier Olathe, Kansas UsA
Reply to
William Frazier
I am confused about your "modern" and "old fashioned" winemaker designations. Frankly they are silly and artificial. If one wants to make fine wines there are few ways to do that regardless of whether or not one is a home winemaker or a professional. Period!
Your long and arduous posts about PA, alcohol content and other minutia are exercises in "reductio ad absurdum" For example, we have 400 gallons of Pinot Grigio that currently has an RS value of 0.67, a pH of 3.41 and a TA of 0.610. It also has an alcohol level of 15.1%. The starting Brix was 25 degrees and the theoretical alcohol calculates to 14.3-14.5% . Accounting for this is dependent upon quite a few factors, and is best theft to the theorists on this thread for the moment. Other considerations are easier to understand. It seems to me that in all of your theoretical considerations you are neglecting the fact that the newer yeasts (ICV D254, ICV D21 and ICV D80 for example) convert sugars far more efficiently and effectively than some of the older yeasts that have been used for years. Thus a must that would have yielded a 12.5% alcohol level using older style yeasts can now result in a wine of 13.5-14% alcohol content starting at the same Brix level.
Similarly a Rose we made from Pinot Noir, picked at 26 Brix, managed only a 14.72% alcohol level even though the RS was 0.07. Why? Different yeast (Lallemand SVG). The theoretical PA was 15.1. Was this yeast an underachiever? No because it did what we wanted and resulted in fruit forward and rather lush wine with a variety of floral characteristics.
All of these data resulted from laboratory testing in a major USA winery laboratory.
My point is that while all of these theoretical considerations are intellectually interesting, they seem to be of little practical value. The alcohol content of the finished wine is the alcohol content in the finished wine, regardless of what one calculates it to be a priori.
Reply to
Jerry DeAngelis
Are you condemning us "little guys" to eternal darkness ?? I would rather light a candle. Comments interspersed:
I had thought that I had made the distinction very clear - but - if not, let me do so now. "Modern" methods evolved with the advent of chemical stabilizers (and sterile filtration). "Old fashioned" refers to the methods used before these things came into general use. Two very different worlds. You obviously understand "modern", so let me point out an example of "old fashioned". I believe the best known example is CJJ Berry's book "First Steps in Winemaking". (Suggest you get a copy). If you look in the index you will_not_find any reference to chemical stabilizers or sterile filtration (keep this in mind when reading the text). And yet, in his recipe section, you will find LOTS of sweet (RS) wines. I can assure you that his wines_were_stable in the bottle !! Folks in this group often ask how they can make a sweet wine without using sorbate. My answer to them is to do it the "old fashioned" way. Silly ?? Nope. Lots of us "old timers" did (and still do) these kinds of RS ferments.
If, after reading Berry's book, you still think that such distinctions are "...silly and artificial...", well - I guess you are welcome to your opinion.
I understand that folks who work only with "the grape" often share this opinion. One need only look at the long lists of "country" (non-grape) recipes to discover that there are_lots_ of ways to make "fine" wines.
Actually, my estimate for 25BRIX is more like 13.6%. 14.3% would indicate a starting BRIX of ~26. And 15.1% would be a little over 27.5. Is there something wrong with both my references AND my hydrometer ?? I have been using both for a _very_ long time. Has something changed in the mean time ?? If so, maybe you should inform UCDavis that the info on their site is wrong because their info supports the numbers I have been using for all these years. They have a "contact" address on their site. Please let us know what they say !! Either way, this is obviously non-typical, and, if I had used a "typical" yeast, I think I would_start_by questioning my own original BRIX reading thinking that I must have taken that reading after the ferment had already started.
I agree. And a winemaker with a little extra time on his hands should at least make an effort to figure out why.
Not familiar with these yeasts but I promise I will look into it. The fact is, that in the references we have been using here, not one of them states that their numbers are only for specific "non-typical" yeasts. Most of them _do_ state that the numbers are representative of typical ferments using typical yeasts !! These numbers and our hydrometers are about the only tools that us "little guys" have and I doubt you will convince any of us that we should simply abandon the use of these tools in our efforts to make better wines.
The *REALISTIC* PA for an _average_ ferment of a 26BRIX must is ~14.3. I need only look at my triple scale hydrometer to confirm this. UCDavis uses an "efficiency/conversion" factor of 0.55. Thus, 26*0.55 = 14.3 and once again, my hydrometer agrees. Many sources tell us that the accuracy of such estimates is ~0.2% ABV. It is not unusual at all that ferments might finish lower than such an estimate. What _would_ be unusual, would be to have them finish substantially _higher_. Which, by the way, is what all of our previous discussions have been all about.
I suspect that the lab results only covered the "after ferment" data. I also suspect that the original BRIX data may have trusted field survey reports or were taken after ferment had begun. No other way I can think of to explain these kinds of anomalies.
Sorry. I thought I was trying to_stress_practical applications.
True. But us "little guys" don't use lab reports and _we_ need some kind of way to come up with realistic estimates. What do you suggest _we_use ???
PS - Believe it not there is no malice in my comments here. I really _am_ only trying to be helpful.
Reply to
frederick ploegman
Margalit in Concepts in Wine Chemistry (2004) uses conversion factor of 0.57 for initial Brix and refers to several references (actually people from UC Davis) that report the conversion factor to be measured between 0.60 - 0.55 in practical fermentations. According to this info, the 0.55 is the most conservative estimate and Jerry's numbers, although on the optimistic estimate side, fall within this range.
I've also heard from a professional winemaker here in BC that they were getting higher final alcohol values for initial Brix measurements than 5-10 years ago. She also thought this was because the current "designer yeasts" were getting more efficient in alcohol production.
Also, keep in mind that most references for the conversion factors are not recent, so if there was a recent increase in yeast efficiency, this might not be reflected in the typical PA fomrmulas in use.
My main question to Jerry would be - how are the wines tasting? That's pretty high alcohol, especially for the Pinot Gris.
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Reply to
I wish I knew what all that meant :-)
It is an apple wine made from a recipe base on that from CJJ Berry's First Steps... I added a blend of acids as per his instructions but didn't check the acidity. (Will have to get an acid test kit).
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