To help,
the recipe :
(note, it's not the legal in france, as it's been fixed by a ministry law, and the official recipe is wrong…)
- fresh nettles (usually before flowering, but it's just for convenience for filtering, flowers and seeds make a mess…) 1 kg. Choose only clean, unstained, nettles, without fungus marks nettles.
(or dried nettles 200-300g)
Don't think that adding more will make it better, it won't.
- rain water 10 liters (No hard water! It must be acid)
- a container, more wide than deep (for practical reasons when mixing the witch soup) larger than necessary. A large plastic bin is fine. Wood is fine, but no metal!
- a place protected of the sun, of wind, with a regular temperature if possible in the 15-25°C range.
- preferably a big tissue bag, or a wood piece to put on the nettles or a cover (with an opening)
- Something to turn the mixture
- A colander (with a 1-2mm net), pieces of clothes or an old tee shirt to filter (not too wide, not to small openings)
Large quantities are easier to control than small ones.
Set the nettles in pieces a few cm long, in the container, cover with the water. turn the mixture to remove the air bubbles. Add the cover.
Turn a few minutes the mixture everyday, or twice a day if it's hot. After 24-48 hours a foam of small bubbles will turn up, it's the first fermentation. It'll last 4-5 days to 2-3 weeks depending of the temperature. The hotter, the faster. Don't go too fast, the timelapse to stop the fermentation is short (a day at best) and should not be missed.
As long as there's the foamy little bubbles, there should be nothing else to do. There should be next to no odor save maybe those of nettles, it can go stronger but never stinky.
When the bubbles stop, the first fermentation is done, it's time to filter and store. The surface of the liquid should be a little oily. Removed the big bits (the big tissue bag helps here), then use the colander to filter, then the tee shirt. The liquid in the end should be quite transparent, though colored (green yellow, but mine is red-brown), the filtering must not be perfect, just spraysafe. The aim is to remove the bits with chlorophyl, that can fuel the second fermentation.
The garbage filtered can be used in compost.
Store in plastic bottles/containers, with no air inside, in the dark and in a fresh place. It should stay fine for months.
There's stabilization processes around, to help conservation. but I have no access to those used by pro-ducers here. So I can't help on this, one may involve lactoserum, another a toxic compound (sulfur dioxide), note that I don't know which are used and how, it may even be something else, it's the only information I've found yet.
If it STINKS, it went thru the second fermentation and should not be used as repulsive, it won't work…
About viruses… I've searched on my own, asked a friend who has access to scientific literature databases, and I have not been able to find:
- if nettles have viruses in common with orchids, not even a list of viruses infecting nettles.
- if viruses survive the fermentation.
So I'm in the dark in this regard.
Hope this helps