Freeze Dried Yogurt Culture Help With Home Made Yogurt?

Help with home made yogurt? - freeze dried yogurt culture

I've tried to do in the oven with yogurt as a starter and not work at all, when my mother bought me a machine bought yogurt and freeze-dried cultures. Well, that does not work.
I incubated for 10 hours (the machine says 7.12 hours). It is still quite fluid! It smells like yoghurt, so I'm pretty sure he did not kill the culture.
Why not?
No machines troubleshooting my instructions and I lose a lot of milk (breast milk).
HELP!