I chopped up the beetroot in to big ish chunks and boiled with a little bit of water to leach the colour out of the beetroot and then sieved out the lumps then I cooked the dyed water over a low heat in an old saucepan with a cup of flour, ½ cup of salt, 1 tablespoon of cream of tartar and 1 tablespoon of cooking oil. The mixture came together in the pan very quickly and was so easy to make. It was a big hit with the kids - and none of that odd manufactured playdoh smell! It kept pretty well too, I wrapped it in tin foil between play times and it was moist and workable for weeks.
I hope you are having a lovely chilled out Sunday