epete28

Original Gravity and ABV

24 posts in this topic

I've noticed that my ABV lines up really closely to the decimal points of my OG, to within 0.3 or so. For instance, I just fermented a batch that had an OG of 1.047, and my ABV is 4.7 on the money. Another I have was OG 1.069 and it finished at 6.6 ABV. Is this the norm? It seems one could just about estimate ABV on OG alone.

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It really depends on the FG, which differs by beer style. Some beers finish lower and drier, while others finish higher and sweeter. The yeast you choose also plays a factor, as different yeast will chew up varying amounts of the fermentable sugars. It's best to stick to the calculations of the difference between OG and FG. 

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45 minutes ago, Big Sarge said:

It really depends on the FG, which differs by beer style. Some beers finish lower and drier, while others finish higher and sweeter. The yeast you choose also plays a factor, as different yeast will chew up varying amounts of the fermentable sugars. It's best to stick to the calculations of the difference between OG and FG. 

Oh, I DO check both readings, it's just a trend I noticed over the last 4 or 5 batches. With MB yeast, S-04, and 05.

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47 minutes ago, Nickfixit said:

It also will depend how much non fermentable stuff is in there. That ups the gravity.

I get that, I was just saying how my ABV has been lining up with my OG, that's all, just an observation. I'll keep paying attention to it on future batches, it's interesting. My Whispering Wheat Hefeweisen did it too, 1.043 OG, 4.3 % ABV.

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2 hours ago, RickBeer said:

Just luck.  ABV= (OG - FG) x 131.25.  

I wasn't saying I was going to just abandon the formula guys, I use it without fail, I was just wondering if anyone else had noticed that kind of symmetry.

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As I said, just luck.  Your attenuation is about 76%.

 

Example:

 

OG 1.010

FG  1.0024 (76% attenuation)

 

10 - 2.4 = 7.6 x 131.25 = 9.97, i.e. 10.

 

You're multiplying the result of OG - FG by 131.25, in other words increasing it by that much.  So, if you divide by that number (1/131.25), you'll see the ".76".  Ignore decimal places, you get the idea.

 

Switch to a yeast that attenuates a lot more, and you'll not match up at all...

 

Note - I probably should look up the formula for attenuation, but you get the idea.  Change yeast, won't match any more.

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51 minutes ago, RickBeer said:

Note - I probably should look up the formula for attenuation, but you get the idea.  Change yeast, won't match any more.

I went back and looked at some recipes and I noticed this trend he was talking about... however, every one of them used 1056, so that makes perfect sense :)

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The science of yeast in brewing is quite fascinating, with many different variables. While most of us are interested in the "add yeast, make beer" aspect of it, things like flocculation and attenuation determine which yeast should be used to make which beer. Then there are the obvious esters that add to a beer'd flavor and aroma. 

In the end, there's a lot to learn about yeast in brewing. I see it as an advanced study. We can mix and match malts and hops all day to help determine flavors, but all of the workings of the yeast can make similar profiles very different. 

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29 minutes ago, Big Sarge said:

 

I'm not going to lie, some parts made my head hurt a little. The science of yeast runs pretty deep. Great read though!

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Stephen King guy are you? We should talk, lol. Skeleton Crew is pretty good.

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1 hour ago, epete28 said:

Stephen King guy are you? We should talk, lol. Skeleton Crew is pretty good.

Ive read:

pet semetary

All the dark tower books 1-7

the wind through the keyhole

thinner

through the eyes of the dragon

firestarter

the shining

1/2 of the stand

the long walk

the girl who loved tom gordon

 

thats all i can think off the top of my head

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22 minutes ago, Creeps McLane said:

Ive read:

pet semetary

All the dark tower books 1-7

the wind through the keyhole

thinner

through the eyes of the dragon

firestarter

the shining

1/2 of the stand

the long walk

the girl who loved tom gordon

 

thats all i can think off the top of my head

I've read about half of those. Most recently, I've read 11-22-63 and Under the Dome. Also Christine back in high school. 

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2 minutes ago, Big Sarge said:

I've read about half of those. Most recently, I've read 11-22-63 and Under the Dome. Also Christine back in high school. 

11-22-63? Cant place that one... 🤔 

 

under the done is a massive book. Congrats to you. 

 

Never read christine but i did see the movie when i was younger. Creepy

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56 minutes ago, Creeps McLane said:

11-22-63? Cant place that one... 🤔 

 

under the done is a massive book. Congrats to you. 

 

Never read christine but i did see the movie when i was younger. Creepy

I can't even begin to count mine. I do know that Geralds Game was my 1st, and Mr. Mercedes was my most recent. He has new work authored with his son Owen! "Sleeping Beauties" I think it's called.

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11 hours ago, Creeps McLane said:

11-22-63? Cant place that one... 🤔 

 

under the done is a massive book. Congrats to you. 

 

Never read christine but i did see the movie when i was younger. Creepy

It's about time travel and the Kennedy assassination. Read it. It's pretty long and awesome. Don't watch the tv show first either. 

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15 minutes ago, Big Sarge said:

It's about time travel and the Kennedy assassination. Read it. It's pretty long and awesome. Don't watch the tv show first either. 

I did read this one actually. Pretty good one. I remember recommending it to my sister in law cuz she likes time travel romances. I always thought that was a strange genre until i read this one. 

 

I would also like to add delores claiborne and on writing to my list of books read. 

 

Since this thread is completely off topic id like to add a few notes on the SK books ive read

 

the girl who loved tom gordon gave me nightmares for a week

 

the shining i found to be the scariest. I feel the two scariest parts of the book were left out of the movie 

 

my favorite is a tie between the wind through the keyhole and wolves of the callah, both dark tower books

 

ive so read joe hills books heart shaped box and demons. Thats stephen kings kid also. Kinda demented books. 

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1 hour ago, kedogn said:

Very interesting book to say the yeast :)

 

Wow!  You went there?  Mods, please consider banning kedogn due to "humor unbecoming a brewer".

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