I've never been successful in the past at building a hot compost pile, so I picked up this starter inoculant at a sustainable ag. conference this fall. I used only half of the starter mix. Hopefully, I can use the mostly finished product to inoculate another compost, and so on. I'm going to try and build the next one around the barrel, because with the cold nights, I fear that the water in the barrel cools the compost more than the compost heats the water, although the warm, sunny days we've been having most likely help to heat the water in the barrel.