Your first year
You’ve done your research, picked a system, mapped your workflow and site, developed goals, and considered options for community collaborations. It’s time to compost! This page lays out best practices for mixing and managing your first batch, monitoring your pile and keeping records, and how to know when compost is done. Let’s get started!
A note on terminology
This toolkit uses the terms “compost” and “composting” with precision:
Composting is the return of organic materials to a rich, stable, humus-like material through a managed aerobic biological process.
Compost is the product of composting.
Food scraps or feedstocks are the materials used in composting, not the process or product itself. Your “compost bucket” is probably more accurately referred to as a food scrap bucket!
The Basics
Your first batch
Step 1: Nutrient Inputs (feedstocks)
The raw materials used in composting are called “feedstocks” or nutrient inputs. You’ll also hear them referred to by color: “browns” are relatively higher in carbon and “greens” are relatively higher in nitrogen. Carbon provides the energy (food) microbes need, while nitrogen allows them to build proteins (grow) and do more decomposing work. The optimal carbon to nitrogen (C:N) range for the decomposing microbes to do their work 30:1-50:1, outside of this range, decomposition slows down.
To the right are examples of materials and the range of C:N you might expect for them.
Adapted from Robert Rynk, On-Farm Composting Handbook, Natural Resource, Agriculture, and Engineering Service, 1992.
Step 2: The Mix
A compost “mix” or recipe is the specific blend of nutrient inputs in your compost system, whether tumbler, bin, or windrow. A good basic recipe is 2 to 3 parts carbon-rich material to 1 part nitrogen-rich material. Just keep in mind that this ratio changes if you’re using material that has a much higher C:N, like wood shavings. In this case, you might only need 1 part carbon to 1 part nitrogen - or less!
Moisture makes the nutrients in organic material available for the microorganisms. Ideally, the mix feels similar to a damp sponge. Too much moisture kills the microorganisms, reduces oxygen, and causes anaerobic conditions; too little slows or stops the process.
A nice fluffy mix ensures that there is enough pore space, which means the microbes will have enough oxygen. Aeration stimulates the removal of heat, water vapor, and gasses during the active composting phase. Too much air slows the composting process.
Use the tools in this section to select a basic mix, tailor your mix to your compost system, or calculate based on feedstock analysis.
Courtesy of VT Agency of Natural Resources, Department of Environmental Conservation, Solid Waste Program. Download here.
Management vs. Patience
Compost happens naturally and is a very forgiving process!
If you don’t have a lot of time, go for the “Simple and Slow” approach. Start with a good recipe & turn when you can, or don’t. It will take longer to get finished compost (12-24 months) but you’ll get there. Time takes care of most pathogens, but not weed seeds.
If you’re eager to have finished compost, paying more attention to the conditions in your compost system will result in a more active (hot composting) process. Reaching temperatures of 131°F or hotter reduces pathogens, kills weed seeds, and results in finished compost in as little as 6-8 months (sometimes less).
Hot composting is like a sprint—quick and intense—while cold composting is more of a leisurely stroll. Choose the method that aligns with your time, effort, and goals!
Step 3: Monitor, Manage – and wait
You’ve mixed your first recipe together… Now what?
The rate at which feedstocks decompose varies with system and management style. The more you adjust for moisture, air, and possibly add more nitrogen or carbon materials, the faster your feedstocks will break down. Monitoring involves observations or tests to ask:
Is the compost too wet or too dry?
Is it too dense and compacted?
Are the temperatures rising, holding steady, or falling?
To understand more about high and low levels of management, check out out tools, video learning, and additional resources in this section!
Good management
Recordkeeping helps you replicate a good process
Management turns a rot pile into a high-quality soil amendment and composting into a partnership between humans and microbes.
Effective management involves regular monitoring of your compost system, ensuring that volatile substances become stable, harmful pathogens are reduced, and a uniform finished product is achieved.
Monitoring is how you know what management is needed. There are many tools and tests you can use, but the most important are your senses! What does the material look, feel, and smell like? Trusting your senses comes with experience.
Recordkeeping helps you replicate a recipe and process once you arrive at one that works well for your system. It’s also a great communication tool if more than one person is managing your system, and it makes troubleshooting issues much easier! Think more about communication needs based on management style.
One of the most critical parameters to keep track of is temperature, especially if you are a certified organic producer, or just want to ensure your finished compost is free of weed seeds..
The Process to Further Reduce Pathogens (PFRP) occurs when composting materials reach a minimum of 131°F for a specified amount of time, which varies by system type.
Here is a brief overview of PFRPs.
Another reason to keep records? It can help in getting funding for your site, as many grantors are interested in the volume of organics diverted from the landfill (and related reduction in greenhouse gas emissions) and the volume of the resulting compost.
Tools in this section will guide you through setting up your pile management practices, recordkeeping, and other best practices.
When is it done?
Curing, evaluating, and putting compost to use
Curing is the final phase of the composting process. The curing process allows finished compost to sit undisturbed for a period of time, typically several weeks to several months. During this time, microbial activity continues to break down organic matter, and fungi begin to take over for bacteria as the compost cools, matures, and stabilizes.
Stability refers to the degree to which the compost has completed the decomposition process and reached a relatively inert state. When compost is stable, the organic matter has broken down sufficiently, and the compost is safe for use in soil, free from harmful compounds, and beneficial for both plants and the environment.
Finished compost is relatively uniform in texture, dark in color, and has an earthy smell. There are tests you can use to evaluate the quality of finished compost .
Courtesy of NYC Compost Project’s MCM: Master Composter Manual. Download the complete manual here.
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Finished Compost: What to look for
Keep learning
with five more content modules
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Your First Year
Get to know the basics of composting. Definitions, materials and recipes, principles of good management, and more. Content to get you going and to come back to as you iterate and improve.
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Year Two and Beyond
Learn to make improvements based on experience. Evaluate your first finished compost and consider how to adapt your system and practices when your farm model changes, or respond to the unexpected.
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Troubleshooting Tips
Strategies and solutions for head-scratching eventualities, from low temperatures to frozen piles to keeping wildlife out, plus deliberations for more experienced composters, such as whether to add an aeration.
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Advanced Topics
Specialized content and advanced topics of the trade, including meeting your compost under a microscope and capturing heat through Compost Aeration and Heat Recovery (CAHR) systems.
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Learning Forum
A forum for any practitioner to pose questions and quandaries for the CAV On-Farm Composting technical team and other experts to address. Find an answer or ask a question to help your on-farm composting get even better.
Not finding what you’re looking for? Search the entire toolkit…
You’ve made a commitment to composting – now get support! Resources in the Organization and Community sections are designed to help your collaborators.
