Working Out Alcohol Content

[Kronos]

There are a few different calculations for working out alcohol content but what is the most accurate.

I have been using SG minus FG then divide by 7.326

 

[Keats]

I don't know if it is the most accurate but I just use this:

http://www.brewersfriend.com/abv-calculator/

 

[Brett74]

I also add 0,2% for priming sugar, I usually use something between 2,5 to 2,7 CO Vols.

 

[dad_of_jon]

I also add 0,2% for priming sugar, I usually use something between 2,5 to 2,7 CO Vols.

you could do OG - FG then after adding priming sugar into a bottling bucket do new OG and de-fizz a bottle to get new FG and add the two together ?

although adding .2 is a lot less hassle :grin:

 

[Clint]

Try this...drink 8...
If you are still standing it's under 4%.
If you are wobbly and slurring it's 4-6%.
If you are lying on the floor it's over 6%.
If it IS over 6% and you are OK you probably need to be in a cage.

Cheers

Clint

 

[Slid]

There are a few different calculations for working out alcohol content but what is the most accurate.

I have been using SG minus FG then divide by 7.326

I divide by 7.5 and concede that whatever you do, an approximation (hydrometer reading) minus an approximation (hydrometer reading) divided by a number around 7.4 is going to be a guess to circa plus or minus 10% on ABV.

So, you compute your ABV at 5% and I say, great, so that means it is probably between 4.6% and 5.5% with an informed guess at around 5%.

What has this this actually told you?

An hydrometer is a guessing stick in the hands of anyone (homebrewing) who is not sufficiently experienced to have little need for one.

Yey-ho, just my little rant on the ingredients measured to the 10g in 1kg and then the output measured by little more spurious accuracy than drinking 4 pints and seeing how you feel.

 

[JapanBrew]

Try this...drink 8...
If you are still standing it's under 4%.
If you are wobbly and slurring it's 4-6%.
If you are lying on the floor it's over 6%.
If it IS over 6% and you are OK you probably need to be in a cage.

Cheers

Clint

Surprisingly accurate this test. It's what I've used over the years.

 

[MickDundee]

I don't know if it is the most accurate but I just use this:

http://www.brewersfriend.com/abv-calculator/

This. The Brewers Friend app is my go to for my ABV and priming sugar calculation needs.

 

[Kronos]

Does anyone recommend refractometers, I have never used one but does this save having to use a hydrometer which in turn would cause less risk to contaminating the beer.

I have seen them for as little as £15.00

 

[geetee]

The way the HMRC work out ABV depends on the final gravity.

For beers that fall between 3.3 and 4.6 multiply Sg- FG x 0.129

For beers that fall between 4.6 and 6.0 multiply Sg- FG x 0.130

For beers that fall between 6.0 and 7.5 multiply Sg- FG x 0.131

Add 0.2% for priming/secondary fermentation.

PS since their duty depends on it I reckon this will be accurate.

 

[JapanBrew]

Does anyone recommend refractometers, I have never used one but does this save having to use a hydrometer which in turn would cause less risk to contaminating the beer.

I have seen them for as little as �£15.00

Yes. They work great but you have to adjust the reading since alcohol distorts the reading. But yes, you only need a drop, which I use a small 15 ml eye dropper thing, spray it with alcohol and take a small sample.

 

[Simonh82]

Brewers friend has two slightly different methods of calculating ABV. The advanced method takes into account the effect of alcohol in reducing the FG reading. They say this only really makes a difference with strong beers over 6% ABV. Under that strength the effect is negligible.

This looks similar to the way HMRC calculate it.

 

[dad_of_jon]

Brewers friend has two slightly different methods of calculating ABV. The advanced method takes into account the effect of alcohol in reducing the FG reading. They say this only really makes a difference with strong beers over 6% ABV. Under that strength the effect is negligible.

This looks similar to the way HMRC calculate it.

that's pretty much most of my beers then :whistle:

 

[Festival Man]

There are a few different calculations for working out alcohol content but what is the most accurate.

I have been using SG minus FG then divide by 7.326

Hello, As you may know, the graph for alcohol content is not linear. therefore the multiplying factor for increasing gravity drops changes. ie, for Gravity drops of between 26.2 and 36 points, you use a multiplying factor of .129. for gravity drops between 36.1 and 46.5, you use factor .130, between 46.6 and 57.1 you use factor .131, Using these factors is the nearest you will get to the v/v content that is within each of these ranges. (There are more ranges of course) Hope you use these. I got them from Stack exchange from someone who knows. Cheers.

 

[Festival Man]

The way the HMRC work out ABV depends on the final gravity.

For beers that fall between 3.3 and 4.6 multiply Sg- FG x 0.129

For beers that fall between 4.6 and 6.0 multiply Sg- FG x 0.130

For beers that fall between 6.0 and 7.5 multiply Sg- FG x 0.131

Add 0.2% for priming/secondary fermentation.

PS since their duty depends on it I reckon this will be accurate.

Perfectly correct, just like I have told on this site, I got my info from The Stack Exchange, its full of bods who know their stuff.

 

[Festival Man]

Perfectly correct, just like I have told on this site, I got my info from The Stack Exchange, its full of bods who know their stuff.

Dont forget to tell them that it is the amount of gravity drop that dictates the factor to use. See my thread, Cheers