Editing Compost (section)

=== Hot and cold composting – impact on timing ===
The time required to compost material relates to the volume of material, the particle size of the inputs (e.g. [[wood chips]] break down faster than branches), and the amount of mixing and aeration.<ref name=":5" /> Generally, larger piles reach higher temperatures and remain in a thermophilic stage for days or weeks. This is hot composting and is the usual method for large-scale municipal facilities and agricultural operations.

The Berkeley method produces finished compost in 18 days. It requires assembly of at least {{convert|1|m3}} of material at the outset and needs turning every two days after an initial four-day phase.<ref>{{cite web|url=http://vric.ucdavis.edu/pdf/compost_rapidcompost.pdf|title=The Rapid Compost Method by Robert Raabe, Professor of Plant Pathology, Berkeley|access-date=21 December 2017|archive-date=15 December 2017|archive-url=https://web.archive.org/web/20171215190533/http://vric.ucdavis.edu/pdf/compost_rapidcompost.pdf|url-status=live}}</ref> Such short processes involve some changes to traditional methods, including smaller, more homogenized particle sizes in the input materials, controlling carbon-to-nitrogen ratio (C:N) at 30:1 or less, and careful monitoring of the moisture level.

Cold composting is a slower process that can take up to a year to complete.<ref>{{cite web |title=Composting |url=https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs144p2_014870.pdf |publisher=USDA Natural Resources Conservation Service |access-date=30 December 2020 |date=April 1998 |archive-date=6 May 2021 |archive-url=https://web.archive.org/web/20210506090827/https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs144p2_014870.pdf |url-status=live }}</ref> It results from smaller piles, including many residential compost piles that receive small amounts of kitchen and garden waste over extended periods. Piles smaller than {{convert|1|m3}} tend not to reach and maintain high temperatures.<ref>{{cite web |title=Home Composting |url=https://ecommons.cornell.edu/bitstream/handle/1813/44638/compostbrochure.pdf?sequence=2&isAllowed=y |publisher=Cornell Waste Management Institute |access-date=30 December 2020 |date=2005 |archive-date=16 October 2020 |archive-url=https://web.archive.org/web/20201016191518/https://ecommons.cornell.edu/bitstream/handle/1813/44638/compostbrochure.pdf?sequence=2&isAllowed=y |url-status=live }}</ref> Turning is not necessary with cold composting, although a risk exists that parts of the pile may go anaerobic as it becomes compacted or waterlogged.