I turn piles until they don't reach 131 F (55 C), then let them sit until they reach ambient temperature. Then turn into a storage bin and let mature for at least 6 months. My most recent pile was turned 7 times, but I'd say 3 is minimum to make sure everything got hot enough. I have 3 platforms and it works well for up to 2 active piles. If I had more compost inputs then I'd expand to 5-7 platforms so I could keep turning the same direction down the line instead of back and forth.