Please check my numbers for a 9% brew

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

senorfartman

Well-Known Member
Joined
Dec 17, 2007
Messages
96
Reaction score
0
All my equations and numbers come from "How to Brew" by John Palmer. This is the first time I've ever brewed a beer strictly by using numbers and I wanted to see how everything looks. I used to teach algebra to 9th graders so I skipped writing out a lot of the math so if there's confusion, let me know.

The goal was an ABV of 9% and a 5 gallon batch size. I assumed an FG of 1.010.



ABV = (OG - FG)(.129) *OG and FG measured in gravity points.

9 = (OG - 10)(.129)
70 = (OG - 10)

Therefore, the OG is 80 or 1.080

_________________________________________________________________________
Now I need to find the attenuation which will show me what type of yeast to use.

FG = OG(1 - AA) *OG and FG measured in gravity points.
10 = 80(1 - AA)
AA = .875

With an AA of .875 or 87.5 in the real world, I need to use a strong ale yeast with an AA between 80 and 100.
_________________________________________________________________________
I decided to use 3 types of grains for this. I'm not entirely sure how it will taste but experimentation is the best part.

The ratio of lbs grain to points per gravity equation with multiple grains is as so where the grain is measured in lbs and the PPG is a constant I found in the book assuming 75% efficiency:

[ ((Grain1 * PPG1)/Batch Size) + ((Grain2 * PPG2)/Batch Size) + ((Grain3 * PPG3)/5) ](.001) + 1 = OG

I know my OG is 1.080 and I have a 5 gallon batch size so...

[ ((Grain1 * PPG1)/5) + ((Grain2 * PPG2)/5) + ((Grain3 * PPG3)/5) ](.001) + 1 = 1.080

Subtract 1 from both sides then divide by .001 and you get...

[ ((Grain1 * PPG1)/5) + ((Grain2 * PPG2)/5) + ((Grain3 * PPG3)/5) ] = 80

Multiply both sides by 5 to get rid of the denominators...

(Grain1 * PPG1) + (Grain2 * PPG2) + (Grain3 * PPG3) = 400
__________________________________________________________________

I swear I totally randomly picked these grains and somehow it came out to equal 400 on the second try. I picked 6 - row, Crystal 40L and Carapils.

Grain, Weight, PPG

6 - row, 11lbs 26
Crystal 40L, 4lbs, 25.5
Carapils, .5lbs, 24

(11 * 26) + (4 * 25.5) + (.5 * 24) = 400

So in a perfect world with everything happening perfectly, this would yield my 9% beer.

I'm thinking about trying it. I don't expect a whole 9% but I should be close and may toss in a little extra grain to help toward getting there. Anyone see any obvious flaws in this (aside from the lack of hops- probably go cascade) Like I said earlier, this is my first time paying any attention toward this side of brewing but if it is accurate, it opens up a whole new world of things to occupy my time at work :mug:
 
aaahhhh!!!!! math!!!!

heh. promash FTW. i can't do math by hand anymore, it's just too boring when i have a spreadsheet already setup and promash installed.

i needz to take an algebra class again :(
 
That's making me dizzy. If you don't have a brewing program, the Recipator is available online for free, I would plug it into that.
 
Well, I've never come across a yeast with 87.5% attenuation. 75% is about the highest I've ever got, so I think you will need to add more grains.
A FG of 1.010 is very low, so I think you will need to add some more grains again.
4 lbs Crystal and 0.5 lbs cara-pils? These both contribute to a high FG. I wouldn't use more than 10% by weight of crystal, and most would say that that is excessive. I think you need to add some more base grains again.
Why use 6 row? It is useful if you are using a lot of adjuncts, but you're not using any, and 2 row gives more PPG.

-a.
 
senorfartman said:
I used to teach algebra to 9th graders so I skipped writing out a lot of the math so if there's confusion, let me know.

Wait a second! Why did I always get in trouble for NOT "showing my math"?
 
Most highly attenuative yeasts rarely go over 80%. If you use White Labs 001 or Wyeast 1056 with a good starter, you'll get 80% apparent attenuation out of it.

Also, use 2-row malt instead. It has a lower protien content and will give you less problems.

The comment about the amount of Crystal is valid. You will have a ton of unfermentables and it will be very sweet, and the FG will never get down low enough.

When making a beer that high in ABV, there will be plenty of unfermentables to give body, so the Carapils is just cmpounding a problem.

If you assume 75% efficiency on the mash, and 80% attenuation on the yeast, this will get you there:

15 lbs 2-Row
1 lb Crystal 40

OG: 1.088
FG: 1.018
Color: 13 SRM
ABV: 9.0%

Mash low, say 150, so you will get a highly fermentable wort and oxygenate the wort like crazy.
 
Moonpile said:
Wait a second! Why did I always get in trouble for NOT "showing my math"?


You didn't go to school in the county did you? I'm from Annapolis and taught at OMHS where I also coach lacrosse.
 
:off:
I went to Key in Annapolis and was starting Varsity goalie for 3.5 years, and got on the All-County North team for 1989. For the All-County game that year they were testing out a 2-point shot from 17 yards out and I was the only one of four goalies (each goalie played a half) who didn't have a 2 pointer scored on him! Yay me.

I once dated a girl who had gone to OMHS though it was my Freshman year of College.
 
Small world, I graduated from Broadneck in '01 and played goalie in college. This is my 3rd year at Old Mill coaching
 
Cool. I lived in the Cape until I was 10, when we moved onto a sailboat in Eastport. I remember when Broadneck HS was just a field!
 
My IIPA started right at 1.080 and only got down to 1.017 and this is including corn sugar to help dry it out. (that's 79% attenuation with 1 pack of rehydrated S-05).

I wouldn't go over half a pound with a crystal addition. I've found that is usually plenty for both color and flavor.

Make sure you aerate/oxygenate sufficiently.
 
Back
Top