Quote Originally Posted by Pleater
I've been knitting my own long socks for about - Oh my - 40 years.

Use the same temperature water for the washing and rinsing - it is the shock of sudden temperature change which helps the shrinking/felting process.

To help with the drying I either put them in the spin dryer - I have a separate from the washer one from when I used to do a lot of yarn and cloth dyeing, or roll them in a towel and stamp on the roll. Don't even think about a tumble dryer within three feet of a woollen garment.
The shrinking of wool, or "felting" is also known to be exacerbated by agitation. This is why directions for hand washing refer to handling the fabric gently and not wringing it out. The wet wool fibres have scales which interlock and prevent the individual fibres from moving relative to each other. Agitation helps the scales to interlock, resulting in the reduced size.

I wash my kilt hose in Woolite by hand. I dry them by wrapping them in a towel to remove the majority of the water and then I lay them out to dry more fully.