On Tue, 13 May 2008 11:22:27 +0100, Tom Anderson
wrote:

On Mon, 12 May 2008, Charles Ellson wrote:

On Mon, 12 May 2008 19:12:12 +0100, Tom Anderson
wrote:

On Mon, 12 May 2008, Charles Ellson wrote:

On Sun, 11 May 2008 21:11:31 +0100, Stimpy
wrote:

On Sun, 11 May 2008 20:42:22 +0100, Mark Morton wrote

Is it written down anywhere how much alcohol needs to be in something
before it's "an alcoholic beverage"?

ISTR it used to be 2%.

You are confusing percentage (of alcohol by volume) with degrees proof.
100deg proof = ~57 % abv ('Merkan measure is different).

Yes, which i've never got. My understanding is that British proof was
defined as the percentage of alcohol at which a mixture of the spirit with
gunpowder would explode when lit. Why the septics switched to the
gratuitously different, chemically meaningless and practically
no-better-than-ABV system of 1 degree = 0.5 % ABV, i really don't know.
The usual sheer wrongheadedness, i suppose.

Both systems seem to be somewhat arbitrary and at the mercy of the
actual composition and moisture content of the gunpowder (and/or the
surrounding atmosphere?).

And the quantity of spirit added to the gunpowder, i'd guess. I assume
there was some kind of British Standard governing the test!

According to the ed.ac.uk site I mentioned elsewhere the measurement
method had changed from setting fire to things to measuring specific
gravity in the 1740s. As different drinks have different ingredients
there was presumably still a practically insignificant element of
error.