Hot composting is the process of using a hot pile of organic waste to generate heat (135° -160° Fahrenheit) and improve the structure of your pile. It’s an easy and cheap technique. Still, this method requires extreme attention to detail, especially the balance of composting ingredients in your bin.
Composting is an excellent step toward sustainable living because about 30% of household waste is made of compostable plant material.
Still, I doubt everyone has the time and patience to wait up to 18 months to harvest finished compost for their indoor potted plants, especially in homes with limited space. So, what other composting alternatives are there to fasten the process?
Try hot composting.
We took it upon ourselves to test this exciting method, and the results were outstanding as they were worth the effort.
Table of Contents
What Is Hot Composting
Hot composting is the process of using a hot pile of organic waste to generate heat and improve the structure of your pile.
This is an easy technique for reducing food waste, saving energy and money, and good soil amendment. Still, this method requires extreme attention to detail, especially the balance of composting ingredients in your bin.
Similarly, you must monitor the temperatures regularly with a range expectation of 135° -160° Fahrenheit.
Otherwise, the pile will compost too slowly when cold or start a fire when it overheats.
The Difference Between Hot and Cold Composting
The most significant difference between hot and cold composting is the decomposition speed.
Hot composting relies on high temperatures to produce rich compost in the shortest time possible, about 4 weeks, while cold composting takes up to a year.
Other significant differences between hot and cold composting are outlined in the table below:
| Factor | Hot composting | Cold composting |
| Speed | Fast composting process | Fast composting process |
| Type of process | Aerobic (with oxygen) process | Aerobic (with oxygen) process |
| Temperature | Temperature range is 135° -160° Fahrenheit (40-65°C) | Temperatures of below 90 ° Fahrenheit (0-40°C) |
| Maintenance | Requires high maintenance | Low maintenance composting methods |
| Period | Works all year round | Composting process stops in winter |
| Composting materials | Accommodates a broader range of composting materials | About 70% of household food waste isn’t cold composted |
| Presence of weeds | Kills weed seeds effectively | Weed seeds survive in the cold conditions |
| Odor | Rarely produces odors | Releases putrid odors |
| Pathogens | Kills pathogens and harmful bacteria in food scraps | Takes months to effectively kills pathogens in kitchen waste |
| Pest presence | Kills unwanted pest eggs and larvae | Maggots and other pests survive in a cold compost bin |
How Long Does It Take To Make Hot Compost?
It should take about 3 to 4 weeks to make hot compost, provided you meet all the pile requirements and carefully monitor the contents of your bin.
What Is Needed to Make a Hot Compost Pile?
Unlike other composting materials, you must have all materials at hand when building a hot compost bin.
Also, you can’t add organic matter to your hot bin and accumulate it because you want to get the pile heated up sooner than later.
So, what do you need?
Hot composting needs a large volume of compost material in the proper carbon to nitrogen ratio from the construction to harvest. The right carbon to nitrogen ratio increases your pile’s microbial activity raising the heat significantly.
But what’s the best browns to greens ratio for your compost bin?
Different sources will give you varying figures depending on the gardener’s experience. Still, the standard ratio that produces reliable results is 25 parts carbon to one part nitrogen-rich source by weight.
Hot Composting Basics/Guide
Hot composting becomes an easy procedure once you have enough material required for the process.
1. Equipment
You will need these tools to get you started.
- Compost bin/tumbler
- Compost thermometer
- Watering hose
- Shovel
2. Ingredients
- 2/3 parts brown (carbon-rich) materials
- 1/3 part green (nitrogen-rich) material
3. Procedure
Follow these steps to get rich dark brown compost for your garden.
- Choose a convenient composting location with direct access to the sun’s rays and away from shade.
- Set up your compost bin or enclosure, ensuring an efficient drainage system.
- Add your brown and green materials in the correct ratio and mix well.
- Water the compost lightly, distributing moisture evenly throughout the pile.
- Monitor your compost’s temperature using the compost thermometer.
- Turn your compost after the first four days and then after every second day for an entire week to ensure proper aeration.
- Harvest your compost and use it on your garden plants.
4. Tips
The following tips should help you cover the basics on your checklist.
- Get the Right Size Compost Container
Your compost tumbler or bin must be at least four feet wide by four feet wide. If your bin is too small, your pile won’t heat up sufficiently or uniformly.
You can opt for a bigger bin, but four feet is enough for a manageable one.
- Place Your Pile in the Sun
The sun helps your hot compost bin achieve the required temperatures fast and speeds up the decomposition process.
Shade, on the other hand, cools down your pile and slows the process.
- Mix the Materials
Most composting methods require layering in bulk, while hot composting requires you to mix up the materials instead.
What to Hot Compost
Hot composting uses high temperatures to break down the toughest organic materials that would’ve been unsuitable in other methods.
For example, animal and dairy products or manure are some of the most frowned-upon composting materials in cold composting. Not only do they take an eternity to decompose, but they also attract pests and produce foul odors.
However, a hot compost bin allows you to properly decompose these ingredients, provided your pile meets the right expectation.
Some common brown and green materials you can hot compost include the following:
Brown Materials
These are carbon-rich sources such as:
- Wood chips
- Sawdust
- Shredded newspaper
- Dead leaves
- Corn stalks
- Small twigs
Green materials are nitrogen materials, including:
- Grass clippings
- Coffee grounds
- Farm animal manure
- Vegetable scraps
- Eggshells
- Fruit peels
Green Materials
Pros and Cons of Hot Composting
Like other composting methods, hot composting comes with its benefits and limitations for gardeners.
| Hot composting pros | Hot composting cons |
| Fast composting process | High maintenance |
| Works all year round | Unsuitable for vermicomposting |
| You can compost almost anything | Nutrient loss |
| No foul odor | Requires temperature checks |
| Kills weeds, pathogens, larvae | Fire hazard |
Pros of Hot Composting
1. Fast Composting Process
Hot composting gives you nutrient-rich organic compost faster than most available methods.
The organic material in a hot compost bin takes about 3 weeks to break down into finished compost giving you a regular supply of natural fertilizer for your garden bed.
2. Works All Year Round
Some composting methods remain unsuitable during specific seasons, such as cold composting in the winter. Adding more composting materials while using cold composting only piles up your bin and creates rent-free breeding grounds for pests.
On the other hand, a hot composting system sustains decomposition in your pile all year round, provided you meet the right temperature.
3. Accepts a Wider Range of Compost Materials
You can decompose a wider variety of food wastes using hot composting than other standard composting methods.
Hot composting uses high temperatures of up to 160° Fahrenheit to break down all kinds of kitchen scraps fast and evaporate water from the bin.
An effective drainage system prevents soggy food waste that would’ve otherwise attracted pests or stank in a waterlogged bin.
4. Kills Weed Seeds Faster
The high temperatures reached in hot composting are hot enough to kill any weed seeds that would’ve drained compost nutrients after sprouting.
5. Rarely Produces Odors
The biggest causes of foul odors in your compost heap are a wet pile and composting unsuitable ingredients such as animal manure or dairy products.
Yet, hot composting uses high temperatures to evaporate excess moisture levels in your bin and can break down animal manure faster than other methods like cold composting.
6. Effectively Kills Pathogens
Food waste, especially the types that have started going bad, contains many pathogens and bacteria harmful to humans. Animal manure also has deadly pathogens like e-coli that cause lots of harm when consumed in diseased plants.
Hot composting exposes these pathogens to temperatures of up to 65°C for extended periods ensuring their destruction in the finished compost.
7. Destroys Pest Eggs, Larvae, and Rodents
Flies are common in compost bins because they’re attracted to rotting materials. Rodents are also available whenever you decompose food waste which they can scavenge.
In a regular compost bin, flies would cause an infestation of maggots from their eggs, while the rodents leave behind droppings and decaying matter, causing putrid smells.
On the other hand, it’s too hot for rats and flies eggs to survive in high temperatures from hot composting, leaving you with a pest-free and nutrient-rich compost for your garden.
8. Effectively Breaks Down Pesticides and Herbicides
You can add plant material from your garden waste to a compost heap, provided the crops weren’t treated with chemicals.
Traces of herbicides and pesticides affect the chemical composition of your compost heap and the proper composting process.
Hot composting, however, effectively uses high temperatures to break down these chemicals, giving you safe and rich compost.
Cons of Hot Composting
1. Requires High Maintenance
Hot composting requires lots of attention and care to get a good quality harvest. You must ensure your compost has the right balance of carbon to nitrogen, consider the proper material layering, monitor the pile’s moisture levels, and keep an eye on the interior temperatures.
A compost thermometer is an ideal instrument that monitors your compost’s internal temperatures forcing you to purchase one at your nearest garden shop.
2. Unsuitable for Vermicomposting
Vermicomposting introduces wrigglers like earthworms to your compost bin to help speed up the composting process. These worms also introduce new microbes into your pile to break down organic matter faster.
Yet, these microorganisms can’t survive under high temperatures. The heat generated from a hot compost bin only favors heat-friendly bacteria, and you might need proper curing to find a solution for the issue.
3. Nutrient Loss
Valuable nutrients are lost whenever your compost pile overheats. High temperatures in hot composting can cost you a specific degree of nutrient loss.
While the remaining amount would still be enough, it’s incomparable to the one from other methods like cold composting.
4. Fire Hazard
Compost fires aren’t common, but they’re also not impossible. Carbon-rich materials like dry leaves will catch fire when your hot compost bin reaches extreme temperatures.
Thus, you must use a compost thermometer to monitor your compost’s temperature regularly and ensure it doesn’t exceed the accepted amount.