In the meantime I had also been doing some research into how I could continue with the solar dyeing experimenting and I bought a Kilner jar, white vinegar and some white DROPS yarn. I unwound some of the DROPS alpaca into hanks and soaked it for half an hour in 4 parts water to one part vinegar. Then I layered it into my jar with loads of onion skins (just the brown part) and then filled the jar with the water the yarn had been soaking in. Then I left it for 2 weeks and let the sun do it's work!
Last weekend I took both sets of yarn out of the dye and they are beautiful. Now I know I'm hooked on solar dyeing! I washed them out with baby shampoo but I'm definitely going to get some proper wool wash because I'm not keen on the smell.
I'm constantly thinking of other things to try - coffee, beetroot & berries are all in my to do list - and I keep coming across things in the kitchen & garden and thinking "that would be a good dye!" But I also need to think what I might make with all the yarn!
I did try dyeing in the microwave with food colouring too but it wasn't that successful and I ended up with a pale pinkish-grey yarn below and not the deep purple I was going for. I pre-soaked as before in water/vinegar. Not sure where I went wrong. If you have any tips, please leave me a comment!