ALCOHOL MEASUREMENT

[mac]

Don't they need an accuarate ABV number for tax purposes ?

I suppose they have the abv of each batch brewed so that would be how duty is calculated.

[arturobandini]

It's entirely possible to work out the ABV of a beer mixed with another beer of a different ABV.

[edit1now]

The last Guinness keg I saw outside the club at work said 4.3% ABV.

[mac]

I don't really think Guinness are saving up for a gas chromatograph or a infra red spectrometer for the brewery.

[trucker5774]

It's entirely possible to work out the ABV of a beer mixed with another beer of a different ABV.

I dont know how that would work...........please help!!

[edit1now]

Easy way - 1 litre of 4% plus 1 litre of 5% mixed together. Each litre will have the average or arithmetic mean of the ABVs:

(4 + 5)/2 = 4.5%

Bigger quantities? Multiply the number of litres of 4% by 4, and the number of litres of 5% by 5, add the results together and divide by the total litres:

27 litres of 4% ABV plus 13 litres of 5% ABV = 40 litres total

(27 x 4) + (13 x 5) = 108 + 65 = 173

173/40 = 4.325% ABV

[trucker5774]

Surely this will only give the average ABV of 2 beers (both with known ABV) mixed together............we are trying to find the ABV of one which we know nothing about. Even applying the same theory by using a hydrometer and measuring the gravity of each, will only show the average gravity

[yogester]

Distillation of a largish sample and then dilute distillate back to starting volume with water and use the old hydrometer. Not as accurate as an ebuillometer but reasonably accurate (at least with wine it is).

See here:-
http://www.monashscientific.com.au/Alco ... lation.htm

[ADDLED]

Distillation of a largish sample and then dilute distillate back to starting volume with water and use the old hydrometer. Not as accurate as an ebuillometer but reasonably accurate (at least with wine it is).

See here:-
http://www.monashscientific.com.au/Alco ... lation.htm

Im not sure many of us have a still in our sheds... mine got siezed by the excise men

[mac]

£1.4bn profit in the last six months of last year, you'd think the tight sods would be able to buy a shinny machine so they could work it out.