Alcohol free attempt fail...

Hi,
I tried to produce an alcohol free beer for my step-sister who is pregnant. It didn't work and I don't really understand why. I need your suggestions. There are the processes I used :

1) Canadian 2 row malt + carafoam = OG: 1.042
2) Mash at 83°C (181°F) for more body and less fermentable sugars
3) Only primary (wyeast Abbey ale) for 7 days = FG: 1.011
4) Final alcohol supposed to be 4.1%ABV
5) Heat primary to 80°C (176°F) for 1h30 to evaporate ethanol and mixing 4-5 times
6) Bottling with dextrose and adding fresh yeast
7) After 3 weeks, samples were tested on a GCMS (gas chromatography - mass spec) by a specialized company
8) Result : 5.1%!!

So, I don't really know what happened. There is more alcohol than it suppose to be. The only mistake I have done, I think, it's that I didn't stir continuously when I heated it to evaporate alcohol...

I would guess that you didnt get hot enough to drive off the ethyl. 176 is only 3 degrees above boiling, so if you had any error, the alchohol remained. I would bring it up to 185 - 190 to be certain.

mashing at 181F is how you extract tannins from the grain and immediately denature all your enzymes. there would have been no starch or long chain sugar conversion at all in that mash. at that point you were really just steeping the grain in hot water, not 'mashing'.

and when you are distilling off the alcohol, instead of heating the beer to 176F or higher, normally you pull a vaccuum on the container to lower the boiling point enough so that you dont change the flavor of the beer. heating it again after fermentation can add considerable amounts of negative flavors. normally you pull enough of a vacuum on it so that the boiling point of ethanol is lower than 120-140F.

from those gravities, you only had about 60% attenuation, which is low for that yeast. which is probably explained by lack of available sugars for it to eat. you should also have 4% ABV, which means that either your annalysis company was wrong, or your measured OG and FG numbers arent accurate (more likely).
pint.com.au - Brewing Calculator - Alcohol and Attenuation

if you are really going non-alcoholic for someone pregnant, you should force carbonate, as bottle conditioning will add even more alcohol (albeit a small amount).

audger said:

mashing at 181F is how you extract tannins from the grain and immediately denature all your enzymes.

Click to expand...

Denature enzymes, yes. Tannin extraction is much more dependent on pH than temp, though. If it wasn't, you couldn't do decoctions. In a decoction mash, you boil the grain, yet you don't get excessive tannins from it.

Post your exact recipe as well as mash and boil volumes. Your stated measurements seem a bit off.

sounds like broken thermometer was the problem. a 181F mash would never get close to 74% attenuation.

Docthorjp said:

2) Mash at 83°C (181°F) for more body and less fermentable sugars

Click to expand...

That's a double mistake. 1) 181F is too high and won't have any enzymatic activity. 2) While you want residual sugars, mashing soooo high will create too much of it.

If you mash at normal temperatures (say 153F), and evaporate the alcohol, the body will increase. Alcohol is, by nature, "thinner" than the normal body of a beer.

I might actually consider mashing LOWER to prevent too much residual sweetness, say 150-151F.

M_C

I don't think you can effectively remove ethanol from a water solution by heating it to the BP of ethanol. Or at least it would take a lot longer than 1.5hrs.

You might be better off doing something like steeping some specialty grains, crystal and a generous amount of dextrine malt, then boiling that for a bit with some hops to approximate a beer without fermentation.

Lennie said:

I don't think you can effectively remove ethanol from a water solution by heating it to the BP of ethanol. Or at least it would take a lot longer than 1.5hrs.

Click to expand...

This. I mean, it sounds simple, but if you're not boiling, you're not boiling. You're just doing hot evaporation. And while that is faster than a cool evaporation, I don't think you can expect to drive of a significant amount of ethanol in a reltively short period of time without boiling it.

I don't know what the actual boiling point of a 5-6% ethanol solution is, but its probably up around 205 deg F.

Plus when you do boil, the steam coming off is the same ratio as the solution at first, and only ratchets towards the 95% ethanol (the azeotrope) as the distilation progresses.

Lennie said:

Plus when you do boil, the steam coming off is the same ratio as the solution at first, and only ratchets towards the 95% ethanol (the azeotrope) as the distilation progresses.

Click to expand...

File:Vapor-Liquid Equilibrium Mixture of Ethanol and Water.png - Wikipedia, the free encyclopedia

The vapor coming off is actually significantly richer in ethanol that water. Where you get into azeotropes is when you're doing fractional distillation as you move up your column. i.e. if you recovered the vapor, and then boiled some of that, and recovered that vapor and boiled some of that, etc, the vapor would be increasingly high in ethanol, until you hit the azeotrope, and then no amount of boiling and recovering vapor would change your composition.

Anyways, sorry for rambling into somewhat

I stand corrected on the first part of my statement. I still don't think it will work for making a low alcohol beer.

Lennie said:

I stand corrected on the first part of my statement. I still don't think it will work for making a low alcohol beer.

Click to expand...

it could be used to make a low alcohol beer, but whether it can be used to make a good low alcohol beer is another question entirely, which I think may be your point.

If you made a small beer (1.035) and mahsed really high (160F) so it would finish around 1.020 you might get a low ABV beer to do your evap technique on.

You know pregos can have some alcohol right? My wife is an ob, I know!

Maybe this is a noob question but how is 4.1%ABV an alcohol free beer? Or am I not understanding correctly?

Lunchtime said:

Maybe this is a noob question but how is 4.1%ABV an alcohol free beer? Or am I not understanding correctly?

Click to expand...

Reread step 5

My instincts tell me that a pregnant woman should be able to enjoy a very moderate amount of alcohol. Of course this is horribly taboo, but the children who suffer from FAS had mothers that consumed considerable amounts of booze. I really don't see a liter of Mild throughout a weeks time amounting to any kind of risk, and I'll bet I could get the blessing of several physicians on that arrangement. The kind of beer we drink is chock full of nutrition, and I considerably different than having a couple mixed drinks every day. I would feel way weirder about my wife having a diet soda every day than a 6 ounce glass of low gravity beer.

Gotcha.

Ok, I am thinking why go thru all the trouble. But, people would probably think the same thing about lots things I do...
So, one alternate route you could go down is making wort, then diluting with water to approximate finishing gravity of what ever beer style you are attempting, then carbing the "alcohol free" carbonated beer. So in other words, just skipping the fermentation step. The esters wouldn't be present, and I've never done this, but, sometimes my wort tastes sooooo good coming from the mashtun, I've often wondered what this would taste like in a alternate beverage form. Anyway, good luck in your quest! Perhaps you may just have to brew up and lager away some tasty congratulatory brews for after the pregnancy!

bighorn_brew said:

I've often wondered what this would taste like in a alternate beverage form.

Click to expand...

prolly like malta

bottlebomber said:

My instincts tell me that a pregnant woman should be able to enjoy a very moderate amount of alcohol. Of course this is horribly taboo, but the children who suffer from FAS had mothers that consumed considerable amounts of booze. I really don't see a liter of Mild throughout a weeks time amounting to any kind of risk, and I'll bet I could get the blessing of several physicians on that arrangement. The kind of beer we drink is chock full of nutrition, and I considerably different than having a couple mixed drinks every day. I would feel way weirder about my wife having a diet soda every day than a 6 ounce glass of low gravity beer.

Click to expand...

This.

dcp27 said:

prolly like malta

Click to expand...

Never tried it, but from the description, sounds heavy and cloyingly sweet. I would want more carbonation, and some bitterness, basically, a craft non-alcoholic beer.

OK OK... sorry but I will not be able to answer all of your questions!! First of all, I think bighorn_brew is right, I will brew a good one for the birth of the baby instead!! Secondly, I know that pregnant women can drink one beer or one cup of wine per day without problems. But with the coming holidays I thought it could be a good idea to brew a beer without alcohol so she could drink 2 beers without stress.

Now, I will considerate all of your suggestions and tried to develop another method... for the next baby, because I agree with the fact that brewing beer is for alcohol!! and taste...

So, thanks to all of you for your help! And I wish you a Merry Christmas and a Happy New Year!!

Docthorjp said:

OK OK... sorry but I will not be able to answer all of your questions!

Click to expand...

We don't care, its only your thread for the first three posts.

Happy Holidays to you too and thanks for bringing up an interesting topic. I rarely think about producing low ABV beers.

Look into reverse osmosis: http://www.desline.com/articoli/7861.pdf

MC

I have had success removing alcohol from homebrew after two failed attempts.
It is possible I am pleased to say. You need to go well above 176 degrees, my
success came from boiling and the flavor was still good. My failures came exactly
the same way as the OP by heating to 170-odd degrees. This should still be possible
if you do it for many hours. I boiled for about an hour and a half and let the resulting
and obviously lower final volume of the liquid be my guide. I used also a campden
tablet since I did not have a chiller, to keep out unwanted bugs. After you boil,
prime and cool, make sure you re-aerate somehow before you repitch new yeast
or the beer may not carb well.

Denny said:

Denature enzymes, yes. Tannin extraction is much more dependent on pH than temp, though. If it wasn't, you couldn't do decoctions. In a decoction mash, you boil the grain, yet you don't get excessive tannins from it.

Click to expand...

in a decoction, the grist (which is where the tannins are) is not subjected to temperatures over 172, but left in the mash tun. only wort is drawn off and boiled. you are correct though, that too-high of a pH will also cause tannin extraction.

This. I mean, it sounds simple, but if you're not boiling, you're not boiling. You're just doing hot evaporation. And while that is faster than a cool evaporation, I don't think you can expect to drive of a significant amount of ethanol in a reltively short period of time without boiling it.

Click to expand...

if the boiling point of ethanol is 173, than you are boiling ethanol at 173. just because the majority of the liquid doesnt boil at 173 does not mean that you are not boiling off ethanol at that temperature.

After you boil,
prime and cool, make sure you re-aerate somehow before you repitch new yeast or the beer may not carb well.

Click to expand...

you should never do this. do not airerate already-fermented beer uness you are trying to induce off flavors. this is exactly how to produce diacetal.

You need to go well above 176 degrees

Click to expand...

the only problem with that is heat destroys the desireable flavors in the already-fermented beer, and induces undesireable off-flavors and will completely undo your hopping schedule. hop aromas are the first to be destroyed. and if you cant reach the boiling point without negatively effecting the beer, then you would need to reduce the boiling point. you do that by changing the pressure on the liquid.

audger said:

in a decoction, the grist (which is where the tannins are) is not subjected to temperatures over 172, but left in the mash tun. only wort is drawn off and boiled. you are correct though, that too-high of a pH will also cause tannin extraction.

Click to expand...

I'm sorry, but in a traditional decoction mash you pull part of the grist and boil it. The liquid, which contains the enzymes, remains in the mash tun. The method you describe is used in a triple decoction mash as the third decoction. At that point, conversion is complete so you can boil the liquid and denature the enzymes.

audger said:

in a decoction, the grist (which is where the tannins are) is not subjected to temperatures over 172, but left in the mash tun. only wort is drawn off and boiled. you are correct though, that too-high of a pH will also cause tannin extraction.

Click to expand...

Actually, this is not true. You do, indeed, pull off grain in a true decoction.

Edit: Sorry, Denny already pointed that out.

Althought it's minimal, but the act of naturally carbing your bottles with yeast and sugar will produce alcohol as the bottles carb up.