I'm new to yeast washing and starters, I have my first sitting in a mason jar in the fridge as well. From what I know and have done, after multiple times decanting and washing, there would be three layers in your jar. The middle layer is the yeast you want. The top clear layer is basically wort and the bottom is trub. Decant the top clear layer off and pour most of the middle into a starter without disturbing the trub and you should be good to go. Hope this helps!