Ahh!!! .....and what if you were given some unwashed etc fleece a year ago in a bin bag and it is still sitting in your shed??? Not used it cause it looks rubbish... what will have happened to it stored incorrectly and any top ideas for 'spoilt' fleece? Pillowcases at the ready for my first shearing in 2 weeks eeekkk, I can hardly wait.
Ooh lots of things will have been going on in that bin bag
It certainly will not have improved in quality over the past year. Unskirted fleece is the worst thing to store - all those poopy bits will contaminate the rest of the fleece. The lanolin will have 'set' ie become hard and the wool will be compacted - completely unnapetising. If there have been any holes in the bag, then the clothes moths will have got in and their larvae will have had a great old time eating their way through the wool, hatching out and laying another generation. If the bag has been lying on the floor you may well have nests of mice or insects in it. If it has been stored damp, or if the bag has caused the fleece to sweat, then the wool itself will have started to rot.
If you suspect moths have got in, burn it because just opening the bag will release a cloud of moths and they will get to your new clip.
I store my fleece in new woven polypropylene sacks, tied tightly at the top, checked for any holes, then hung up in a dry barn with some air circulation, but out of the sun - sun will heat up the fleece and will also destroy woven polypropylene, which is photodegradable. Storing on the floor is a bad move, leaving fleece in a sack which has a hole in is a bad move and as everyone has said, storing in plastic bags is a definite no-no unless you have washed the fleece. Moth will still get to washed fleece, but you can seal it in plastic bags to keep the horrible, wretched, nuisancy things out.