OG/ABV calculator

[dph]

Hi guys, first brew for year or so.

I used to have a weblink to a site that worked out %ABV with corrections for temperature of OG and FG, but no longer.

Can anyone help?

Thanks,

[Kristoff]

Try this one, in the pull down menu it allows for hydrometer correction too.

http://myhomebrew.com/ac0.html

[RichardG]

I've also got this link;

http://www.liquorcraft.com.au/wa.asp?id ... etails=106

I note with interest that this one gives a different ABV than Kristoff's. I used the example of the Norfolk Nog I bottled last night with an OG of 1.041 and an FG of 1.014. My link gives and ABV of 4.1%, the other one gives 3.5%. You take your choice! maybe someone can confirm the actual calculation? I know there is one, but can't for the life of me remember what it is.

[Kristoff]

I've also got this link;

http://www.liquorcraft.com.au/wa.asp?id ... etails=106

I note with interest that this one gives a different ABV than Kristoff's. I used the example of the Norfolk Nog I bottled last night with an OG of 1.041 and an FG of 1.014. My link gives and ABV of 4.1%, the other one gives 3.5%. You take your choice! maybe someone can confirm the actual calculation? I know there is one, but can't for the life of me remember what it is.

That's a bit worrying

[andywood]

i have looked at a few abv calculators and they all give varying results (+/-0.5%).

I used to have a vinoprovare (sp), anybody use these regularly?

[dph]

Thanks chaps, I too get different results from the two links - 4.4 and 4.9.

[RichardG]

This got me thinking, so I decided to look into it a bit more. After some searching on the interweb thingy I found a number of different online calculators and a formula for working out ABV. Basically it's OG - FG x 131 = ABV. So, in the case of my Norfolk Nog I have 1.041 - 1.014 (0.027) x 131 = 3.537%, and most of the online calculators agree with that.

Now this got me going on something else. In the case of my Nog Woodfordes claim an ABV of 4.5% from 40pts. To get that I'd have needed an OG of 1.053. That's alot higher than I actually got suggesting there wasn't anywhere near enough fermentables in the cans. Can it be coincidence that Woodfordes is manufactured by Muntons? Clearly for any future cases I'm going to need to have a spare bag of DME to bulk it out. All in all it's left me feeling slightly less than impressed (though maybe this was just a one-off).

[RichardG]

...though now the rants over and I've had a chance to think about it further I realise chucking extra DME in could upset the hop balance. The easiest thing to do is just reduce the brew lenght (I seem to recall Norfolk Nog originally being advertised at much less than 40 pints) which will maintain the balance. So, in future I think I'll go with 20ltrs rather than 23ltrs. Thoughts anyone?

[Dill]

(I seem to recall Norfolk Nog originally being advertised at much less than 40 pints)

According to the box, Norfolk Nog brews 40 pints, as do all the other Woodforde kits with the exeption of the Head Cracker, which is a 24 pint kit.

[RichardG]

Indeed it does DIll, at 4.5%, not 3.5%! I also have a Muntons Golden Ale Midas Touch; claimed as 40 pints at 5%. It actually came out with an OG of 1.046 and an FG of 1.014 giving an ABV of 4.2%. Now I'm quite happy with a 4.2% brew, and the ABV isn't the be-all-and-end-all by any stretch, but in both cases above I'm not getting anywhere near the claimed ABV, and what bugs me is that the manufactures are making claims that, in my experience at least, have no connection with reality; leaves me feeling slightly 'done'. Now if Muntons had claimed 4 - 4.5% for Golden Ale, I'd definately have still bought it. If Woodfordes had claimed 3.5 - 4% for Norfolk Nog, I may well have still bought it (I may not), but at least I'd know what I was getting. It just seems to me that inexperienced brewers could end up becoming disallusioned with their results and either quit certain manufactures or even our entire hobby! I intend to check OG at about 75% of the guide brew lenght and see what I get then. If it's well above what I'd expect for a certain target ABV, I'll drop a bit more. If not, I'll leave it there. Either way I'd certainly be interested in other peoples thoughts and experiences of this.

[arturobandini]

Like most kit makers I've taken refuge in the wisdom of Chris's excellent website www.18000feet.com . On here Chris states that to work out an ABV of your beer you do the following calculation. Original Gravity (without decimal points) minus Final Gravity (again without the decimal points) divided by 7.5 . So to work out the ABV of my Belgian Golden Ale I did the following.....

OG 1070 - FG 1010 = 60 / 7.5 = 8

So i've brewed an 8% Belgian Golden Ale. I've used some of the online calculators too and got widely varied results so I'm just going to stick with experience on this one.

[Dill]

I entirely agree with what you are saying Richard, but manufacturers will probably claim to reach their stated abv, the kit has to brewed too "exact brewing conditions" I.E. Temperatures, water conditions etc.etc.

Although the Wherry that I brewed came out at about 4%. and tasted great, I was under the impression that the priming sugar I put in the bottles would take it up to the 4.5% abv mark.

[vacant]

To be fair, my Midas touch (25th Aug OG 1052, 4th Sep FG 1015) came out at close to 5%. I use (OG-FG)*0.129 which I got from Inland Revenue calculations, +0.23% assuming the 85g of bottling sugar ferments completely.

see section 30.3

[Jim]

To be fair, my Midas touch (25th Aug OG 1052, 4th Sep FG 1015) came out at close to 5%. I use (OG-FG)*0.129 which I got from Inland Revenue calculations, +0.23% assuming the 85g of bottling sugar ferments completely.

see section 30.3

If the IR use that figure it's quite likely to be right - it's equivalent to dividing by 7.75, which is roughly midway between Chris's figure and the 8.06 I found ages ago when I did my recipe formulation page.