calculating potential alcohol in beer

Okay so iv been talking to some ppl about my recipe im doing and some are saying to add more grains and more malt because they think i need more to achieve a 5% alcohol beer. i feel like im doing the calculation right so maybe we can discuss if i fudged up and what is the proper way to figure out potential alcohol percent.

Granola bar and malt beer recipe

According to my paper chart that came with my hydrometer. For 4.7% alcohol you require 79.9 g of sugar per liter. so my carboy is 4.5 liters X 79.9 grams sugar = 359 g total sugar. my granola bars are 162g sugar + 200g DME = 362g total sugar. so i required a total 359 g sugar and im providing 362g sugar. this should equal 5% alcohol, roughly.

There may be some mystery sugars added when i steep the granola bars and thats fine. It probably wont be much , maybe raise the alcohol percent from 5% to 5.5%.

Well if I understand right you are only using granola bars for fermentables. I have no clue how much of the bars will ferment or what you will end up with since not all sugars are created equal and some will not ferment unless converted.

Hehe saying that though I want to know how it turns out

Yeast can only ferment simple sugars. the sugar in your granola bar is both complex and simple so not all of it will ferment to alcohol. Post your recipe and perhaps we can help.

Never brewed with granola but if you want a 5% beer shoot for a og of about 1.055 and if your yeast cleans up nicely you should have a 5.6%-5.0%

BobC said:

Yeast can only ferment simple sugars. the sugar in your granola bar is both complex and simple so not all of it will ferment to alcohol. Post your recipe and perhaps we can help.

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Okay, here is what I Have so far.

Granola and Dark DME beer recipe:

4Liter-1gallon size batch

45min - steep 300g of granola - 160F then sparge with hot water
60min - 1 tbsp organic mollases (adds minerals since Im using reverse osmosis water)
60 min - 50g dark DME
20 min -350g dark DME
15min - 4grams Irish moss - there are proteins in the granola, I thought the IM would help.

7grams cascade sterling hops 60 min
7grams cascade sterling hops 20min

Why are you using granola bars to make beer?

chri5 said:

Why are you using granola bars to make beer?

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I was wondering this, myself.

chri5 said:

Why are you using granola bars to make beer?

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Because he ate all the Oreos .

chri5 said:

Why are you using granola bars to make beer?

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well....why not!?! It all started when I noticed a bag of granola bars sitting in the cupboard and seen they expired feb 18th. I have grown to not care for eating dry grains anymore as food, I prefer to enjoy grains soaked in water and then yeast sprinkled on top of them The fermentation can do a good thing with grains and water. Anyways I was reading the ingredients and noticed barley malt extract as a main ingredient, along with Oats, brown sugar, golden syrup and other things that make me think BEER! They were made by presidents choice and were preservative and color free, which was even more of a hint to experiment with these.

I actually brewed it yesterday and it went pretty good although I had trouble keeping the boil at exactly 160 like my recipe called for, my boil jumped up to 170 and 175F but I think the majority it spent around 165F. Either way the wort smelled and tastes great and I ended up at an SG - 1.041 so about 5-6%. its been about 20 hours since pitching and its bubbling nicely.

I think where your friends are getting a different number is that you're presuming that all the "potential alcohol" will actually be converted to alcohol -- with beer, that almost never actually happens.

With normal ale yeast, you've done a good job if you get down to 1.010 or so. Even beers with more aggressively-fermenting bugs -- saisons, lambics, sours, etc. -- stop around 1.004, 1.005.With weird adjuncts (say, granola bars, just for a crazy example), you'll probably finish even higher, because the sugars you steep out of the oats and what-not will be less fermentable than well-mashed malted barley.

Play around with this: http://www.rooftopbrew.net/abv_calculator.php

Best-case, starting at 1.041 and getting down to 1.010, you're looking at 4.1%; I'd be impressed if you clear 1.015 (3.5%).

feinbera said:

I think where your friends are getting a different number is that you're presuming that all the "potential alcohol" will actually be converted to alcohol -- with beer, that almost never actually happens.

With normal ale yeast, you've done a good job if you get down to 1.010 or so. Even beers with more aggressively-fermenting bugs -- saisons, lambics, sours, etc. -- stop around 1.004, 1.005.With weird adjuncts (say, granola bars, just for a crazy example), you'll probably finish even higher, because the sugars you steep out of the oats and what-not will be less fermentable than well-mashed malted barley.

Play around with this: http://www.rooftopbrew.net/abv_calculator.php

Best-case, starting at 1.041 and getting down to 1.010, you're looking at 4.1%; I'd be impressed if you clear 1.015 (3.5%).

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yea thats a good point, Im hoping for around 1.010 as a FG but well see. 3.5-4% might be okay, it would make a good session beer, something Iv not yet brewed. Althought it almost seems a waste to brew a batch of beer and not have much alcohol potency to it lol. I wonder if its too late to add another 100g of DME in the carboy?

If you add the dme you are kind of going against what you said out to do, right? See what you can do with the granola. What do you have to lose, a packet of yeast....

Ugh, either way this sounds gross to me. Enjoy your "beer"

Oh, Idunno, what's in granola? Oats? Sugar or honey? Maybe some spices, nuts, or fruit? These are all ingredients with long, storied histories in brewing.

His biggest challenge is gonna be figuring out what category to enter his Belgian oatmeal holiday raisin session nut brown under.

feinbera said:

Oh, Idunno, what's in granola? Oats? Sugar or honey? Maybe some spices, nuts, or fruit? These are all ingredients with long, storied histories in brewing.

His biggest challenge is gonna be figuring out what category to enter his Belgian oatmeal holiday raisin session nut brown under.

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Hahaa Thats pretty funny. actually these are pretty basic granola bars with many of the same ingridients as you would find in beer. as soon as i seen "barley malt" i knew i had to try it. there is also oats rice and golden syrup in them and they are preservative and color free. so i mean id say this is a pretty decent substitue to experiment With.