I can offer one bit of advice in hindsight:
If you are fitting a tap to a drum, test it for leaks under a full head of pressure before putting any weeds in!
So, 6 months on, how is this p
Inconclusive so far:
Barrel 1 (at home) was filled, but the drain tap leaked and I haven't yet faced the unpleasant task of emptying it out. There's still some liquid in it (definitely anaerobic) - it must have self-sealed after the pressure got to a manageable level.
Barrel 2 (pressure tested and up on our land) isn't full yet (it takes quite a lot of baby gorse pulling to fill one!)
Barrel 3 has 200 litres of lovely liquid seaweed fertilizer.
I'll start barrel 4 as part of the spring clean-up at home.