How Does an Insulated Aerobic Composter Work?

If you’re looking for a way to turn kitchen scraps, garden waste, and even toilet waste into rich, nutrient-dense compost for your garden, an insulated aerobic composter could be the solution you’ve been searching for.

These clever composting systems speed up the composting process while keeping odour in check and reducing the need for constant turning. But how exactly does an insulated aerobic composter work, and why might it be the right choice for your composting needs? Let’s dive in.

What is Aerobic Composting?

Before we jump into the specifics of the insulated variety, let’s take a moment to understand aerobic composting in general. Aerobic composting is the process by which organic matter (such as food scraps, garden waste, and plant material) decomposes in the presence of oxygen. In this process, micro-organisms,(in this case “good” bacteria) break down the organic material into nutrient-rich humus (a fancy word for well-decomposed organic matter) with the help of oxygen.

These micro-organisms thrive in warm, oxygenated environments. As they break down the organic material, they generate heat, which speeds up the composting process. This is why aerobic composting typically produces a hot pile (around 55-70°C). The heat also destroys harmful pathogens too.

In a traditional composting setup, like a garden compost pile, the materials are exposed to air and oxygen, which helps keep the composting process aerobic. But it’s not always easy to maintain the right conditions - especially during the colder months or if we experience lots of rain. That’s where insulated aerobic composters come in.

The Insulated Aerobic Composter

An insulated aerobic composter is essentially a composting system that’s built with insulating materials to help retain heatand moisture while maintaining airflow for optimal decomposition through theuse of air pipes and anadjustable vent.

The insulation works by keeping the internal temperature of the compost pile stable, even in colder weather, while still allowing oxygen to reach the organic material. This unique combination of heat retention and oxygen flow can speed up the composting process and ensures a more efficient breakdown of organic material.

Here’s a breakdown of how it works:

1. Insulation Keeps the Heat In

One of the key features of an insulated aerobic composter is its insulating walls. These walls are made from double-walled plastic material, internally packed with insulation. The insulation prevents the compost from losing heat too quickly, which is especially important in our colder UK climate where lower temperatures can slow down the decomposition process. In simple terms, the insulation acts as a "blanket" for your compost, keeping it at the right temperature range for fast and efficient decomposition. In winter, decomposition will naturally slow down but in an insulated composter waste will still decompose, just at a slower rate.

In aerobic composting, maintaining a consistent temperature (typically between 50-70°C) is essential. If the temperature drops too low, the decomposition slows down, and the microbes don’t work as efficiently. Conversely, if the temperature rises too high, the microbes might die off, and the composting process could stall. Insulation helps to moderate these temperature fluctuations, keeping the conditions just right for your composting microbes.

2. Aeration for Oxygen Flow

While insulation is essential for maintaining heat, an insulated aerobic composter still needs a way for oxygen to flow into the system to support waste decomposition. This is where the "aerobic" part of the composter comes in. The system includes air vents, that allow air to flow through the organic material. In summer when the ambient temperature is likely to be warmer the air vents can be opened fully, whilst in cooler month these can be closed to (but not fully shut) to hold in the heat. These air pathways ensure that the microbes have enough oxygen to thrive, without suffocating the pile. There’s a handy temperature gauge built into the front of the Biolan 220 eco thermos-composter to help you regulate what’s going on.

3. Moisture Retention

Another benefit of insulation is that it helps maintain moisture levels inside the composter. The decomposition process requires moisture to break down organic materials, but if the compost is too wet or too dry, it can hinder the microbial action. Insulated composters help retain moisture by creating a stable internal environment, which helps the decomposition process move along more smoothly.

Systems like the (Eco composter 220) come with liquid management features, in the form of a drainage system to prevent excess liquid buildup.  Gravity allows liquid to run to the bottom of the composter, down a seepage pipe and into an external container. This liquid can be used as a fertiliser (also known as ‘compost tea’.) This makes it easier to maintain the ideal moisture level for decomposition.