Formular For Alc Volume

[iluvbeer]

Hi, does anyoe know what the mathamatical formular is to determin the alc vol. What i am trying to do is make up my beer log on microsoft excel. So i need the formular, so when i put in my sg readings it automatically puts in my final alc volume. As i am only new to this brewing i dont need all the fancy stuff that some of these diarys have, just a simple one. So when i get it working i will post it here and let anyone who wants it have it also.

Thanks :icon_chickcheers:

 

[crozdog]

(start gravity - final gravity)/7.36

 

[iluvbeer]

(start gravity - final gravity)/7.36

So is that start og minus finish og then divided by 7.36??????????, because im getting some weird results with the calculater. Im not that good with math, so i hope i dont sound stupid. Also had a few brews, starting to kick in.

 

[kabooby]

See the brackets

eg (1.046 - 1.010 = 36) 36/7.36 = 4.89%

Kabooby

 

[iluvbeer]

Thanks, i was just confused by the decimal places. I will get working on excell and post it soon

 

[iluvbeer]

I think i have worked it out, i have attached an easy diary which you can edit anyway you like. When you put in you sg readings dont put in the decimal point in. ie 1.080 put in 1080 and same with finished sg and you should get the right alc automaticaly.

hope it works. :beer:

View attachment BREW.xls

 

[brettprevans]

Hi, does anyoe know what the mathamatical formular is to determin the alc vol. What i am trying to do is make up my beer log on microsoft excel. So i need the formular, so when i put in my sg readings it automatically puts in my final alc volume. As i am only new to this brewing i dont need all the fancy stuff that some of these diarys have, just a simple one. So when i get it working i will post it here and let anyone who wants it have it also.

Thanks :icon_chickcheers:

you could try searching the site - theres heaps of differant alc calculators [with and without formula]. theres also one here . While a forumla may be basic it doesnt take into account fermentability of ingredients which is hwy a more complex calculation is better.

 

[crozdog]

you could try searching the site - theres heaps of differant alc calculators [with and without formula]. theres also one here . While a forumla may be basic it doesnt take into account fermentability of ingredients which is hwy a more complex calculation is better.

CM2, valid points, however isn't the calculator you linked to better suited to determining the likely effects of ingredients when formulating recipes? When I try it, I can't put my "measured" FG in.

The (OG-FG)/7.36 formula works with actual measurements, not theoretical. You can also use it to help reverse engineer a commercial product you may be trying to clone ie work out the OG. I like this formula cause its easy to remember.

 

[brettprevans]

CM2, valid points, however isn't the calculator you linked to better suited to determining the likely effects of ingredients when formulating recipes? When I try it, I can't put my "measured" FG in.

The (OG-FG)/7.36 formula works with actual measurements, not theoretical. You can also use it to help reverse engineer a commercial product you may be trying to clone ie work out the OG. I like this formula cause its easy to remember.

yes your quite correct Croz. I was in a rush and being a bit lazy so I didnt say anything along the lines of your points.

Although in saying that, I really havent had much problem with the calulator I listed, my OG generaly end up being about what it says I should expect. of course that cal doesnt work for AG or minimash

 

[chovain]

Thanks, i was just confused by the decimal places. I will get working on excell and post it soon

Yeah - that's a pretty common gotcha. Some of the maths used in brewing needs the "specific gravity" (e.g. 1.046), while other bits need "gravity points" (e.g. 46).

A lot of the formulas can be fairly easily converted between the two by twiddling the numbers a bit. (OG - FG) / 7.36 only works with gravity points (or as you mention below, it also works with SG*1000). To work with specific gravity instead of points, you can use: (OG - FG) * 136. If your OG/FG are 1.046 and 1.010, then you get (1.046 - 1.010) * 136, which is 4.9%abv.

CM2, valid points, however isn't the calculator you linked to better suited to determining the likely effects of ingredients when formulating recipes? When I try it, I can't put my "measured" FG in.

Brewers' calculators that use the ingredients are really handy if you can't measure OG or FG for some reason. For example, priming sugar adds about 0.2-0.4% to your abv depending on how much you add. Since you can't reliably measure the FG of the primed beer, you need to calculate it based on the sugar you've added to the bottle (if you care). I normally just calculate my abv with the OG/FG, then add on 0.3 for priming.

 

[Fatgodzilla]

Yeah - that's a pretty common gotcha. Some of the maths used in brewing needs the "specific gravity" (e.g. 1.046), while other bits need "gravity points" (e.g. 46).

A lot of the formulas can be fairly easily converted between the two by twiddling the numbers a bit. (OG - FG) / 7.36 only works with gravity points (or as you mention below, it also works with SG*1000). To work with specific gravity instead of points, you can use: (OG - FG) * 136. If your OG/FG are 1.046 and 1.010, then you get (1.046 - 1.010) * 136, which is 4.9%abv.
Brewers' calculators that use the ingredients are really handy if you can't measure OG or FG for some reason. For example, priming sugar adds about 0.2-0.4% to your abv depending on how much you add. Since you can't reliably measure the FG of the primed beer, you need to calculate it based on the sugar you've added to the bottle (if you care). I normally just calculate my abv with the OG/FG, then add on 0.3 for priming.

Then there is great unwashed ignorant buggers like me who don't really care what the alcoholic reading is. When we want a stronger brew, add more fermentables. Or we just trust our Beersmith calculations as being close enough !!

 

[chovain]

Then there is great unwashed ignorant buggers like me who don't really care what the alcoholic reading is. When we want a stronger brew, add more fermentables. Or we just trust our Beersmith calculations as being close enough !!

SWMBO insists that I calculate mine, and calculate the number of standard drinks in a bottle (or schooner for the stuff I keg). It's apparently something about being responsible when people come around and want to drive home. I'd rather they drank more and picked up their car the next day myself, but who am I to argue?