Here are some easy tests you can do to see if your compost has matured and is ready to use.Plastic Bag Test
Take a handful of compost from the interior of the pile and moisten it well. Put the compost in a plastic bag and seal it. Keep the bag sealed at room temperature for five to seven days. Then open the bag and smell the contents. It should have a pleasant, earthy, soil-like smell. If it smells foul or rotten or a bit like ammonia the compost is not completely finished.Germination Test
This next test of compost maturity is a bit more work but is also more sensitive and reliable. The test uses fast germinating seeds (e.g. radish) to determine if enough phytotoxins are left in the compost to inhibit germination.
*If the compost germination rate is significantly less than that of the plain soil the compost is not yet mature and needs further time to settle down.