I'm happy to say the digester is up and running beautifully after a series of blunders killed the biology over the Christmas holidays.
I didn't notice that somehow the switch to the digester heating cables was turned off for over a month and the digestate temperature had dropped to 4C! The methanobacterium was also suffering from a bumper crop of citrus in the greenhouse because the compost bucket heading to the digester was consistently full of citrus peel. So, the digestate went acidic and the gas production died. Time to dump it out and start fresh, and that's a stinky, messy, yucky job, especially in the winter. Luckily I've only had to do it a couple of times over the years, the acrid smell lingers on clothes and skin for days.
The timing was great actually. A company trimming hedgerows on the island dumped three loads of wood chips on my farm. A perfect match for composting, I poured the nasty smelling acidic digestate over the chips and added all the ashes from the wood furnace to raise the pH.
Time to start up the digester, I made a trip to Night Owl Farm for a few buckets of fresh cow manure, and here I am a couple of weeks later happily burning the gas, catching whiffs of healthy smelling digestate and diverting my kitchen waste sans citrus to the digester.