whats best to clean old container with, noob question

Mmmm don't know about plastic, but I used to clean my glass ones with broken eggshells in some water and keep swishing it about to remove any marks, then sterilise with the cheap milton type thing they use for baby bottles.

Someoen said once that bicarb was good, but I didn't rinse the demi john out well enough and the wine tasted horrible!

Won't a normal wine-making steriliser do it? Perhaps with more than one wash?

maybe, i will give it a go,i just thought there maybe a revolutionary new kills/cleans everything stuff on the market  its got some black stuff that needs blasting big time.i will try soaking for a week twice see how it goes

Suggest you soak it with hot water and detergent overnight, then empty and put in a handful of gravel and a cup of water and give it a good shaking. Excellent exercise too.

i have an old plastic demijohn thingy from a few years back but my other half has used it for various liquids since not detergents or anything but i was wondering if this could live again with a nuclear type clean to remove some black marks inside.not done homebrew for 10 years but i want to try some fruit wines now i have an allotment.any ideas

Freecycle!! I have had about 20 glass demijohns two 5 gallon brewing containers and all the paraphernalia that goes with it of freecycle. People take up brewing for a few years and soon loose interest so there tons out there. Also if you look on Ebay and therefore in the shops you will find plastic demijohns which have an inbuilt cork with hole for an air lock they are very cheap. I have not seen them with full seals not sure if they come that way? Either way I use them in-between IE next racking goes into glass demis. Hope that’s helpful JB

I use a BIG bottle brush fixed to an electric drill.    Cheers,   Tony.

Some of the suggestions are a little abrasive for plastic in my opinion, scratches in the plastic are a haven for germs and bacteria. As has been suggested i would chuck it, if you really want to keep it and sanitise it try iodophor.

its gone now i'm scared to death by it  use it,clean it, chuck it, :lol:got some glass demijohns sparkling bright  thanks for all your comments it helped to make up my mind