Alcohol Content

Is there a way to find out how much alcohol content is in your beer without having an original gravity?

I'm having this issue because I am adding sugar/fruits in the fermentation tank after some of the fermentation has already happened.

Is there another way to get a proper reading for something like this?

If you didn't take an OG then there is no other process you can do. However you should be able to work out a rough OG based on the ingredients you used.

Have some friends over, see how drunk they get off it.
Send it in to some kind of lab for testing.
Raise it to somewhere between the boiling point of alcohol and the boiling point of water, let the alcohol boil off, and see how much less beer there is.
List the ingredients list, and someone will probably punch it into a calculator which will give you your approximate OG (this will be more accurate if the brew was extract, if it was all grain your efficiency will play a big role).

dorklord said:

List the ingredients list, and someone will probably punch it into a calculator which will give you your approximate OG (this will be more accurate if the brew was extract, if it was all grain your efficiency will play a big role).

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This is the correct answer. If you are doing an extract batch, what the brewing software gives you will be pretty dead on. If it's ag, then if you are using the calculator and aim for a 70-75% brewhouse efficiency, and tend to have your process dialed in, it will be the same thing, you can approximate it. Then you can figure out how many points the fruit will add...then taking you FG, and using the traditional formul, Og-fg x 131 should give you a ballpark.

I think I'll do that , and try to back it up with burning off the alcohol content technique.
Do you have a link to the calculator I should use?

Best free one there is. I used it for a year before I went to beersmith

http://beercalculus.hopville.com/recipe

The burning off the alcohol technique doesn't work because:

1. It is a simple physical fact that you cannot boil off all the alcohol until you have boiled off all of the liquid
2. You will be evaporating a lot of water as well.

People seem to think that the ethanol portion of a water/ethanol solution boils independently at the temperature at which ethanol boils. Oddly, they don't make that same mistake when thinking about other solutions (eg I think when making candy, people realize that the water portion does not start boiling at 212F).

You could boil the living hell out of it and then replace the lost volume with water and get and assume you have close to zero alcohol and the measurement would then be reasonably approximate (closer than the .131 thing anyway) but I am talking about an hour or more of boiling and I mean boiling the mixture not raising it to the boiling point of ethanol.

Can you elaborate on this, please? The closet distillers among us may dispute you here.

Revvy ,

That beer doesn't seem to compensate the ABV with the "misc" field.
Does beersmith have a nice library like the beer calculus you gave me?

Tedpro said:

Revvy ,

That beer doesn't seem to compensate the ABV with the "misc" field.
Does beersmith have a nice library like the beer calculus you gave me?

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I don't know what you mean, compensate....you put in all your fermentables first (not counting your fruit) that will give you a rough Original gravity.

Then you figure out how much fruit you added and look online to see how much sugar that will contribute. Once you have that you take a normal fg reading when the beer is done, then you use the formula I gave you above to figure out the abv

remilard said:

The burning off the alcohol technique doesn't work because:

1. It is a simple physical fact that you cannot boil off all the alcohol until you have boiled off all of the liquid
2. You will be evaporating a lot of water as well.

Click to expand...

You can't boil it ALL off, but you can boil off the vast majority. As far as the amount of water evaporation, there will be some. In fact, it should be pretty close to the same amount as if you held the same quantity of water at the same temperature, so you could control for that. (For example, you could take 1 gallon of beer in a pot and heat it, and in another pot of the same dimensions, put 1 gallon of water and heat it to the same temp, weigh them both, and take the difference. The difference in weight between them should be the alcohol that came out of the beer. It won't be all of the alcohol, but you'd get a rough approximation.

People seem to think that the ethanol portion of a water/ethanol solution boils independently at the temperature at which ethanol boils. Oddly, they don't make that same mistake when thinking about other solutions (eg I think when making candy, people realize that the water portion does not start boiling at 212F).

Click to expand...

I'm not sure what you're trying to say here. The sugar in the solution does change the boiling point, but when I made candi sugar, I started with 1 lb of table sugar, and I ended with 1 lb of candi sugar. The water that I mixed the sugar went someplace.

You can also find out if you have a hydrometer and a refractometer using a tool like this: http://brew.stderr.net/refractometer.html
Or the one in Beersmith.

remilard said:

The burning off the alcohol technique doesn't work because:

1. It is a simple physical fact that you cannot boil off all the alcohol until you have boiled off all of the liquid
2. You will be evaporating a lot of water as well.

People seem to think that the ethanol portion of a water/ethanol solution boils independently at the temperature at which ethanol boils. Oddly, they don't make that same mistake when thinking about other solutions (eg I think when making candy, people realize that the water portion does not start boiling at 212F).

Click to expand...

Actually, the "heat to 175Fish" method of making low-alcohol beer works. It's fractional distillation (the same method that allows you to heat petroleum to different points to separate it into gasoline, kerosene, heating oil, and other component parts).

The method is sometimes used for making "nonalcoholic" (actually, low-alcohol) beer.

Until you hit the azeotropic point (which is around 191 proof) you get independent boiling of the alcohol and the water. You can't distill an ethanol-water mixture above the azeotropic point, but you can boil off the ethanol below it.

(The azeotropic nature of ethanol/water mixtures is why Everclear is 190 proof and not 200).