One other important element to consider when composting outdoors is size. The helpful bacteria that power your compost live at the center of your pile. Adding more to your pile during colder months further protects the center, allowing it to remain active even during prolonged cold spells.
Inside
The biggest concern people have with indoor compost bins is the smell. Thankfully, this doesn’t have to be the case if you take the appropriate steps
When adding ingredients to an indoor bin, it’s important to create a bed of soil where you can place old food scraps and other nitrogen rich “green” materials. Be careful, too many nitrogen-rich materials can lead to your bin creating offensive odors. In order to prevent this, it’s best to bury your “green” materials in the dirt and cover them with carbon heavy “brown” materials.