Double-check my Alc% calc

[jet]

I made a chardonel dessert wine by freeze-concentrating the juice. My starting SG was 1.154 and the ending was 0.992. My formula gives an approximate alcohol percentage of 22, but that does not seem possible. Would someone mind double-checking my calculation?

TIA

 

[cpfan]

Your arithmetic is correct. I got 21.5%, but different folks use different factors.
1.154 - .992 * 131 = 21.22%
1.154 - .992 * 133 = 21.55%
1.154 - .992 / 7.36 = 22.01%

What I wonder about is your starting sg. The scale stops at 1.150 on my hydrometer. Was the hydrometer scale basically all the way out of your juice at the start?

Steve

 

[jet]

Mine goes to 1.160.

I double-checked the ending SG. I cannot help but wonder if I misread the starting value.

 

[JasonH]

What yeast did you use?

 

[jet]

Lalvin K1V, which has an "Alcohol tolerance up to 18%".

 

[AlFulchino]

and i got 21.89% w starting sg minus ending sg andthen dividing by .0074

 

[cpfan]

and i got 21.89% w starting sg minus ending sg andthen dividing by .0074

Al:

Like I said different folks use different factors. I use 133 cause it seems to match the scale on my hydrometer, and is in the middle of the range.

jet:

methinks you are worrying too much. What difference does it really make?

Steve

 

[AlFulchino]

i agree Steve..i was just giving an example...and just for some added info...the TTB allows a winery a bit of leeway... in reporting abv....for instance if i were to place on the label 11.5% the wine would be permitted a 1% allowance up and down from that 11.5

 

[Wade E]

Yep, I come up with 21.72% If your sg's are right your yeast was crazy!!!!!!!

 

[AlFulchino]

possibly...just possibly, you had some native yeast in the air and it took over...

 

[cpfan]

possibly...just possibly, you had some native yeast in the air and it took over...

1. are native yeasts more resistant to alcohol? I thought the opposite.

2. K1V is called a Killer yeast. I kinda doubt that a native yeast would have stood a chance unless it was vigourous before the K1V was pitched.

Steve

 

[jet]

Al:

Like I said different folks use different factors. I use 133 cause it seems to match the scale on my hydrometer, and is in the middle of the range.

jet:

methinks you are worrying too much. What difference does it really make?

Steve

It's not a huge thing. It won't affect what's in the glass... I was just curious.

Thanks

 

[wvbrewer]

That is pretty good. I always thought you would have to EC-118 to get that much alcohol, but I bet it is smooth.

 

[AlFulchino]

Steve said : "1. are native yeasts more resistant to alcohol? I thought the opposite."

i agree Steve...but something happenned w his wine...either his yeast in his package was not what it was supposed to be...or something mutated along the way...or maybe he did have a native yeast floating around that could handle it

remember even packaged yeast that can handle high alcohol was at one time ...native somewhere

it is possible that his yeast trickled to a finish and then something else took over.....i could be wrong...but something happened here...he might want to package it

 

[Wade E]

I agree, save the less from that and use it to jump start a wine that stops early on you.

 

[AlFulchino]

he might have to feed that new mother... unless he can find a way to dry it

 

[Bailey]

I made a chardonel dessert wine by freeze-concentrating the juice. My starting SG was 1.154 and the ending was 0.992. My formula gives an approximate alcohol percentage of 22, but that does not seem possible. Would someone mind double-checking my calculation?

TIA

Did you freeze concentrate after fermentation?
If so - it wouldn't matter where the yeast max'd out would it? The freeze concentration would remove mostly H2O raising the Alcohol % beyond what any yeast could tolerate.

 

[AlFulchino]

that is interesting Bailey...but wouldn't you be more correct if you were to boil off the H2O and then you would have a higher percentage of alcohol...

freezing doesn't remove h2o but then again i am no chemistry expert..am i missing something?

 

[jet]

The juice was frozen prior to fermentation (afterwards would be distilling).

The juice is like alcohol, in that it has a lower melting point than water. As it thaws the water stays frozen longer, giving a more concentrated must. The SG was off the scale at the beginning, I has to wait until enough water thawed to dilute down to a fermentable level. Home Winemaking Step by Step by Iverson talks about it.

 

[AlFulchino]

are you saying that you took your sg while you still had frozen water...? if you did then fine that is your answer...

but i find it hard to believe anyone would take an sg reading w ice in the primary

i can see it as an experiment to see where it stands or to veer off in ones own direction and make something different...