[vanessa.xx]

I made a batch of each at the back end of last year and was wondering does it go bad? Or can I still use it, also if it does go bad how long does it keep for?

[Baldy]

Don't think the trace elements that you get in the tea(s) are going anywhere so they should be fine.
(However, I'm not a (bio)chemist so what do I know    )

Cheers,
Balders

[ConfusedGardener]

I'm still using mine from last year, and no complaints so far 

[Beetroot Queen]

I will be using mine too

[vanessa.xx]

ahh that's good then thank you

[Spr0ut]

I think the nitrogen might evaporate off to a point but minerals will sit in solution.

[JohnB47]

There was an identical question asked in a recent thread. Perhaps you could find it by searching.

I'm using comfrey brew started three years ago and I'm progressively adding new stuff to the old as I use it. I feel it's unlikely to go off.  Who knows, it might improve with age, like wine!

[ConfusedGardener]

I'm no expert either but I would think it's probably not a bad idea to mix the last of the old with the new. Over time, as the water evaporated (if you leave it open) the minerals should get more concentrated, and there should be plenty of bacteria in there to get things off to a flying start.

[harris467]

On the subject of comfrey tea, I tried to make some a few weeks ago.  There is tons of it growing around our allotments so it made sense to put it to good use!  I was told to get a bucket with a lid, cram as many leaves in as possible and fill with water. Then pop the lid on and let it brew giving it a stir now and then.  I did all this and it was seemingly going well until I lifted the lid and found a thick white mouldy looking skin had formed on the top.  Is this normal? Should I dispose of it and start over? Some advice would be very welcome.  Thanks.

[Nobbie]

On the subject of comfrey tea, I tried to make some a few weeks ago.  There is tons of it growing around our allotments so it made sense to put it to good use!  I was told to get a bucket with a lid, cram as many leaves in as possible and fill with water. Then pop the lid on and let it brew giving it a stir now and then.  I did all this and it was seemingly going well until I lifted the lid and found a thick white mouldy looking skin had formed on the top.  Is this normal? Should I dispose of it and start over? Some advice would be very welcome.  Thanks.

That's fine, just give it a good stir and for goodness sake don't get any of it on anything you bring into the house. It stinks like raw sewage

[Goosegirl]

None of the elements (trace or otherwise) needed for nutrition will alter or deteriorate because they exist in their basic form so can't change in your tea, no matter how old it is. I agree with adding new to old and topping up with water so you keep the same concentration of nutrients in it.

[cadalot]

I have 3 bottle of "black gold" in plastic milk bottles ready for next year