Cold composting is the simplest method of all. You add materials to a pile as you have them and let it decompose slowly at ambient temperature, without much turning or management.
How it works
Just keep adding greens and browns over time. Because the pile does not heat up, it breaks down slowly, often taking a year or more, and it will not reliably kill weed seeds or pathogens. This is sometimes called passive composting, since it relies on ambient microbes and weather rather than active management.
Pros and cons
It requires almost no effort, which is its main appeal. The trade-offs are speed and the need to avoid diseased plants or weeds that have gone to seed. For a faster route, see hot composting.
Setup and planning
Use a bin or defined pile with drainage and room for gradual additions. Store browns so every new layer of kitchen scraps can be covered. Because the pile will not reliably reach sanitizing temperatures, exclude diseased plants, seeded weeds, meat, dairy, and pet waste.
Ongoing routine
Add a reasonable mix over time and turn only when the material becomes compacted or overly wet. Harvest from the oldest section after it looks dark and earthy. A two-bin setup helps because one side can finish while the other continues receiving fresh material.
Common problems to avoid
Patience is the main requirement. Passive piles may take a year or longer, especially through winter. Exposed food can attract animals, while thick grass layers can become slimy. Cover greens, keep air space, and do not confuse partially decomposed material with finished compost.