Need a little calculation help.

Winemaking Talk - Winemaking Forum

Help Support Winemaking Talk - Winemaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

koolaide187

Member
Joined
Sep 3, 2011
Messages
55
Reaction score
1
I am usually good about measuring my wine using the hydrometer before adding the yeast but i haven't done it in about a year. So... I forgot to measure it. I added about 12 pounds of sugar to some black berry wine concentrate as per the directions on the can it came with. It's a 5 gallon batch. It's been fermenting for about 5 - 6 days now and the specific gravity is 1.010 right now. The refractometer reads 9%. I know the refractometer reads sugar content. So is there a way I can tell what my alcohol content is at right now? I don't want it to go over 13% alcohol content and hope it hasn't done that already. I know there is write ups on on how to calculate the content but i am terrible at math but i love me some wine. ;) Any help would be greatly appreciated.
 
Last edited:
Sorbate would stop it along with some camden tablets but I was really just wondering what the alcohol content would be, given the info I provided. I never actually took a reading before I pitched the yeast. I forgot and did the reading the day after and the yeast started within an hour of adding them so I know the day old reading would be off.
 
Last edited:
Where did you get the idea sorbate will stop a fermentation?
 
Sorbate will not stop an active fermentation even with camden. It will only keep an inactive fermentation from starting back up. If you didn't measure your starting Specific Gravity I don't see how you can figure and an ending ABV You can only make an educated guess.
 
Thig, the bottle of potassium sorbate says it will prevent further fermentation. And camden tends to kill yeast/bacteria. I guess if the yeast is going vigorously it would be difficult to kill them. You could always cool your wine to to stop the fermentation process. Pitch in sorbate and it won't restart. There is all sorts of ways to stop fermentation.
 
The general thinking here is that if you let a wine ferment dry, then sorbate it, it will not start back up if you sweeten it. But no one here thinks sorbate will stop an active fermentation.
 
Not sure why everybody is focused on the fact, I said something about stopping the fermentation rather than the general question. You're correct Thig. It won't stop fermentation. Like I also stated previously, it's been a year since I made my last batch so i'm a little rusty on all the additives. ;)
 
It would be so much easier if you could get an estimate the initial s.g.. Even a pert-near number would be better than nothing. Perhaps you could contact the maker of your concentrate for some help?

The procedure listed in the link below describes a way to do the measurement directly on your wine:

http://www.drinksplanet.com/how-can-i-test-the-alcohol-level-of-my-homemade-fruit-wine-375847.html

On the surface, the procedure looks difficult but its just a matter of measuring s.g. of the unfinished wine, remove 500 ml sample from your batch. Boil the sample for a while then add back enough distilled water to return the sample to 500 ml. Measure s.g. again. Use the table in the link to establish the alcohol content of your unfinished batch.

From there, you should be able to back out the initial s.g. of your batch.
 
haha I appreciate the help. It's already done fermenting. I did use a can of raspberry wine right after the blackberry batch and it measured at about 1.070 with 12 pounds of sugar in it. I know different fruits have different sugar levels but raspberry's and blackberry's are very similar in family. So i figured my initial SG was close to the same with the blackberry. Thanks for the help and that way of measuring the alcohol content you posted would be helpful in future events if this ever happens again. I almost thought about buying a EDrometer. They tell you alcohol content but they are like 400 bucks lol.
 
Ha! I hope it worked out for you.

I liked an alternate method that I came across while searching for an answer. It takes two bottles of wine: yours and another at 13% alcohol.

Drink one bottle one evening and the other the next. Compare effects. If you aren't sure, repeat the test.

skaal
 
haha that's a funny test but sounds like my kinda testing. The blackberry is done fermenting. It's dry and has a very strong bite. I'm probably going to rack it once and cut it. I also like slightly sweeter wine so i'll probably add sugar. I don't mind the taste of dry wine but dry wine always makes me feel cotton mouthed. I don't like feeling cotton mouthed when i'm drinking something. Cause i'd have to drink water as a chaser lol. Usually with my experience in wine making i've noticed most of the time wine that has about 13% or more alcohol is about the percentage when i actually start tasting the alcohol. If I had to make an educated guess i'd say this blackberry is at 13 or 14%. The champagne yeast has an alcohol tolerance of 13-15%. I tested the SG and it's at 0.9 so it's eaten about everything in there. Don't over examine what I said earlier because i've added sugar since my last post. I added 2 bags of boiled down blackberries and some actual 100% blackberry juice so i'm sure that got the original SG higher than what was estimated.
 
Last edited:
It turns out that a senior member on this site has an ap for what you needed. ffemt128 or Doug has an ap listed as a part of his signature. fermcalc:

http://web2.airmail.net/sgross/fermcalc/FermCalcJS.html

The ap has a calculator tool a that enables you to calculate % alcohol by inputting refractometer and sg data.

I'm sure to need this one day. Thanks for prompting the question that led me to finding a tool that I didn't know I needed.
 
Back
Top