"Phil L" wrote
snip
3. Allow the brew to ferment from one to three weeks. The length of
time necessary will depend on ambient temperature. Obviously, the
hotter it is, the quicker the process. (However, place your barrel in
the shade during summer to prevent the mixture from overheating and
killing the necessary fermenting bacteria.) The tea is ready when
fermentation has ceased. Test for this by stirring. Avert your nose to
avoid the fumes, then sneak a peak. No more bubbles? It's ready to
use.

Might have a go at this next year, although I can't help thinking "avert
nose" is possibly a mistranslation of "don an industrial grade
gas-mask".

--
Sue