Measuring Alcohol

About a week ago I started a 5-gal. batch of Welch's Concord Grape Juice Wine. I did not measure the SG before I added the yeast. Today I siphoned the must into a secondary fermenter, and measured the SG at 1.005. Is there any way for me to determine the approximate alcohol content of the finished wine? I am very new to wine making, so please be kind in your responses. Thanks.

Go back to the store, buy another bottle of the juice and measure its specific gravity. Use that with the potential alcohol scale on your hydrometer.

Did you add any sugar when you started the wine or do straight juice?

You can use the potential alcohol scale, as mentioned above, but it is less and less accurate the further your final gravity is from 1.000, because that is what that is scaled to. If you finish above 1.000 you'll have less alcohol than the potential, and if you finish below 1.000 you'll have more alcohol than the potential. I use the potential alcohol scale on the hydrometer to give me a ballpark for where it'll end up. And that's enough for most people

Friend: "Wow this is good, how strong is it?"
You: "Somewhere around 13%"
Friend: "Awesome!"

The most accurate way to get your alcohol content is to measure your starting gravity, your ending gravity and calculate it. If you want to get REALLY fancy measure the temperature at the time you take your gravity readings. But it only makes a significant difference if there was a large temperature difference between the two samples. If they're both taken at "room temperature" don't worry about it.

Friend: "Wow this is good, how strong is it?"
You: "About 13.75%"
Friend: "Well, that was specific. Awesome!"


Here's a handy tool for calculating alcohol content, sugar additions, acid, all kinds of stuff. I use it all the time. >>LINK<<

brazedowl said:

The most accurate way to get your alcohol content is to measure your starting gravity, your ending gravity and calculate it.

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The most accurate method is measurement but as that requires a fair amount of fancy, expensive gear or a fat fee to someone who has that gear it hardly seems justified for fermented grape juice.

As wines contain enough alcohol to make use of a Tralle hydrometer practical many wineries use those to get a fairly accurate reading. The required distillation apparatus is not that expensive.

Welch&#8217;s grape juice should end up at about 8% ABV (Alcohol By Volume) with no sugar added if &#8220;fermented out&#8221;, that is - fermented until it won&#8217;t ferment no more.
(fwiw: the bottled product has 36g sugar in 8oz).

Jacob_Marley said:

Welch’s grape juice should end up at about 8% ABV (Alcohol By Volume) with no sugar added if “fermented out”, that is - fermented until it won’t ferment no more.
(fwiw: the bottled product has 36g sugar in 8oz).

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Thanks.

I added 18 cups of sugar to my 5-gal batch. Any idea how that would increase the alcohol content?

I'm going to get a can of frozen concentrate, add the appropriate amount of sugar and water, and measure the the SG to get a sense of the difference with the final product, but in the interim I'd like to have a rough idea of where I'll end up.

It is still fermenting after 11 days, although it has slowed down quite a bit.

No matter what you measure, the alcohol will be somewhere between 11 and 15%. That's where just about all juice wines will finish.

The number does not matter, only the final taste of the product matters.

17% to 18%

juice ... 36g sugars for every 8oz juice
sugar ... 18cups x 7oz (weight) per cup = 126oz ... /5gal = 25.2oz sugar/gal.

Even if you slide the final figures to account for an increase in total batch volume from sugar, that still makes the final product around 17% or better. Just to put that into perspective ... 17% is the same as 34*proof ... so each 2.3 ounces is like an ounce of 80*proof whisky.

Depending on the yeast you used, it may or may not get to 17. Hopefully the yeast gives up the ghost before it gets there and you end up with something a bit less strong and still slightly sweet.
The required faster ferment in higher temps with the right yeast will actually reinforce "Rocket Fuel" flavor ... better call NASA with this one!

Woo-hoo! Momma put away the china and hide the dog, we're havin a party tonight!

What to do?
The ferment might be pretty far along to try and stop it before it gets that strong.
But, anyway ... Now you could ...

Add a couple gallons of water to cut back the strength (not the tastiest option) ... this is assuming that the yeast are still alive and kicking or that the yeast successfully made it to 17%'ish.

Put the whole batch into the refrigerator right away to stop the ferment right where it is ... take a taste - if that's strong enough for ya ... keep it in the fridge permanently (to stop any more fermentation and alcohol production) ... let it settle and clear, and just drink it from there. Still likely awfully strong tho.

or

Let it ferment out to whatever strength it will as normal ... rack into the secondary to clear ... bottle & store as normal etc ... and just, when you serve it, always serve it with ice and mix it with some sparkling water or soda water for fizz and to cut the strength back. That's probably what I would do.

Jacob_Marley said:

17% to 18%

juice ... 36g sugars for every 8oz juice
sugar ... 18cups x 7oz (weight) per cup = 126oz ... /5gal = 25.2oz sugar/gal.

Even if you slide the final figures to account for an increase in total batch volume from sugar, that still makes the final product around 17% or better. . .

Add a couple gallons of water to cut back the strength (not the tastiest option) ...

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The recipe did call for 4 gal. of water before adding yeast, so that should soften it up a bit.

I'm going to siphon off some today and give it a taste.