# How do i determine how much alcohol is boiled off during boil?

### Help Support Homebrew Talk:

#### Grod1

##### Well-Known Member
So a few weeks ago a co-worker of mine pulled a 5 gallon bucket of imperial stout wort before the boil it was left with a cheese cloth over it. it was 1.065. I decided to bring it home and boil it because fermentation seemed to have stopped.it was at 1.026 as i am bringing this up to a boil i think to myself doesn't alcohol boil off above 173°F? I did a quick search and found a quote that said "Water and alcohol form an azeotropic solution. You can't boil all of the alcohol out of the water. I believe you can only get down to about 4 percent alcohol using a simple boil "
great so i have at least 4% remaining
on top of that if i continue to sour/funk this i can add brett and get down to 1.000 and gain an additional 3% abv
I added 2# of sugar to the boil so that will add 3% abv.
I think im looking at at least 10%abv the post boil gravity is now 1.060 in the carboy.
So how do i determine how much alcohol is boiled off during boil.
sorry for the wall of text, thanks in advance if anyone wants to take a stab at learning me something.

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#### mongoose33

##### Well-Known Member
Couldn't you take a hydrometer reading before and after?

OP

#### Grod1

##### Well-Known Member
i have taken many hydrometer sampels at every stage. right now its sitting at 1.060 on a fresh yeast cake.

#### singybrue

##### Supporting Member
HBT Supporter
I'm cornfused-are you boiling after fermentation?

OP

#### Grod1

##### Well-Known Member
yes it open air fermented from 1.065 t0 1.026. so thats 5.5 abv but i cant just add that onto the final gravity because i boiled off "some" alcohol during the boil.
should i just call it 4+ the alc from from my new final gravity when its done.

i also read this quote on google " boiling it(beer) 30 minutes will get it down into the NA, or nonalcoholic, category, which by law means it contains less than .5 percent alcohol

so everything i am reading is contradicting, anyone out there able to clarify things?

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##### Assoc. Winemaker
If you boil, you boiled off all the alcohol. Period. I've had wine samples in the lab and run the alcohol on them and then later, and they had lost alcohol just from sitting on the bench. EtOH is pretty volatile. When it talks about the water and EtOH being azeotropic, it is referring to once alcohol and water are distilled, they get to the point that it is next to impossible to get any more water out of the EtOH as at this point, they are pretty much inseparable. That is why you don't see 200 proof (100% EtOH) as distillers don't have the means to go that far. You "can" get pure 100% ethanol, but you pay through the nose for a small sample from a lab as it takes very special treatment to get it past 95+ percent. The "hi-proof" we get at the winery for adding to our red "port" blend is 95.4 % ABV and that is about as high as one gets.

Hope it helps. You boil, alcohol AND water leave the fluid... and if you boil for any length, you have 0 % left of EtOH.

OP

#### Grod1

##### Well-Known Member
k thanks so the only alcohol that will be in the beer will come from the cane sugar i added and fresh yeast.
my new starting point of 1.060 will be my one and only measurement.

##### Assoc. Winemaker
k thanks so the only alcohol that will be in the beer will come from the cane sugar i added and fresh yeast.
my new starting point of 1.060 will be my one and only measurement.
Yes. You have both Maltose and glucose/fructose now in the mix. Sugar hydrolizes from Sucrose (dibasic) to glucose + fructose, mono basic sugars. It's about equal split.

##### Well-Known Member
Wait what? This whole thread has me confused, our friend here must be confused as to how beer is made. At no point in the beer making process is beer boiled and alcohol boiled off... unless you are distilling but that’s it’s own thing and even then you aren’t bringing the alcohol to a full boil.

What is going on here?

#### casualbrewer

##### Well-Known Member
That's what I am trying to figure out lol. No alcohol is present during a boil in the beer making process but if the beer is already fermented and then boil then yes you will have alcohol in it.

#### Bobby_M

##### Vendor and Brewer
It would be great to understand the goal more clearly. We have a big beer wort that was allowed to open ferment. OP then boiled it and added some sugar. OK but why?

#### Sammy86

##### Still thirsty
Wait what? This whole thread has me confused, our friend here must be confused as to how beer is made. At no point in the beer making process is beer boiled and alcohol boiled off... unless you are distilling but that’s it’s own thing and even then you aren’t bringing the alcohol to a full boil.

What is going on here?
That's what I am trying to figure out lol. No alcohol is present during a boil in the beer making process but if the beer is already fermented and then boil then yes you will have alcohol in it.
From what I can gather the OP has an open ferment and the FG was 1.020...he wanted to add more ABV so he took the new beer boiled it added sugar got a new SG of 1.060 (where he originally started) and is fermenting again.

Why he’s doing this is beyond me when he could have just added sugar and more yeast

OP

#### Grod1

##### Well-Known Member
the goal: get rid of nasty wort a coworker left around at work before owner says something about it./hopefully get some beer out of it.
unboiled wort 1.065- neglected- i take it home to boil so it is safe to consume.I find its down to 1.026.I add sugar so that there is some fermentable sugar in the finished beer.
i appreciate the conversation here but Nabrasken seems to have answered my question unless there is someone who would beg to differ to him. I'm not sure if the rest of you are getting lost or there is other info out there.
it was only open air fermented to get a lil sour going on it was not intended to attenuate so high.

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#### ajinfante

##### Member
MY question would be what will it taste like after the yeast gets boiled? Seems like you have bread soup now.

#### mj1angier

##### Supporting Member
HBT Supporter
MY question would be what will it taste like after the yeast gets boiled? Seems like you have bread soup now.
This.
You still have what ever flavors the wild yeast put in the beer for the most part, be they good or bad. You just go rid of the will beast and alc. Now whether it make good bad or otherwise beer, only time will tell

OP

#### Grod1

##### Well-Known Member
It tasted pretty good to me i blended it with 1.5#"lulo"the fruit in my avatar & 1.5# tamarillo.it was Sour with some weird off flavors but nothing offensive, just a kiss off acetic and now hopped around 35 ibus.You guys think it should get some brett or pedio now that its boiled?