How We Make Living Compost

What we mean by living compost

 

Soil is not just a growing medium.

It is a living ecosystem.

 

Healthy soils contain billions of bacteria, fungi, and other microorganisms that support:

 

• nutrient cycling

• soil structure and aggregation

• water retention

• plant resilience and health

 

When soil life declines, food quality declines.

When food quality declines, human health is affected.

 

Living compost is one way to restore that life.

 

Unlike sterilised or heavily processed composts, living compost is made to support and feed soil biology, not bypass it.

 

 

Where the food waste comes from

 

Generation Soil composts food waste in Bristol using a local, biologically active system.

 

Food waste is collected from households and small businesses, stabilised through fermentation, composted aerobically with carbon-rich materials, and returned to soil within the city.

 

This keeps nutrients circulating locally instead of being transported away and lost.

 

We collect food waste from:

 

• households and businesses participating in the Bristol Living Compost Project

• schools, community groups, and local organisations

• events and food businesses committed to keeping nutrients local

 

Keeping food waste in Bristol reduces transport, prevents nutrient loss, and allows compost to be returned directly to local soils.

 

 

How our composting system works

 

Our process combines fermentation, aerobic composting, and biological maturation. Each stage plays a specific role.

 

 

Step 1: Bokashi fermentation

 

(starting with microbes)

 

All food waste we process is first treated using bokashi fermentation.

 

Bokashi uses beneficial microorganisms to ferment food waste in an oxygen-limited environment. This:

 

• preserves nutrients instead of losing them as gas

• suppresses harmful pathogens

• reduces smells and pests

• gently prepares material for composting

 

At this stage, food waste is not rotting.

It is being biologically prepared.

 

 

Step 2: Blending carbon-rich materials

 

Fermented food waste is then combined with carbon-rich materials such as:

 

• waste wood shavings

• woodchip

• biochar

 

This balances carbon and nitrogen, improves structure, and creates habitat for microbes and fungi.

 

Biochar provides long-term homes for microorganisms and helps stabilise nutrients in soil.

 

 

Step 3: Aerobic composting and heat

 

The blended material is composted aerobically under carefully managed conditions.

 

During this stage:

 

• temperatures rise naturally through microbial activity

• harmful pathogens are broken down

• beneficial microbes multiply

• organic matter stabilises into humus

 

Heat is a result of biology, not something forced.

We monitor conditions rather than industrialising the process.

 

 

Step 4: Maturation and biology-led timing

 

After active composting, the material is allowed to mature.

 

This stage is essential.

 

Maturation allows microbial communities to stabilise, fungal networks to develop, and nutrients to become plant-available without being aggressive or soluble.

 

We do not rush this stage.

 

Time matters in living systems.

 

 

How contamination is managed

 

Living compost cannot be produced at scale if contamination is ignored.

 

We manage contamination by:

 

• providing clear guidance to members

• using fermentation to stabilise inputs early

• manually monitoring input materials

• keeping the system local and small-scale

 

Our model prioritises biological quality over volume.

 

 

What makes our compost “living”

 

Our compost is considered living because it:

 

• contains active microbial communities

• supports fungal and bacterial diversity

• improves soil structure and aggregation

• enhances water retention and nutrient cycling

• feeds soil life rather than bypassing it

 

This is fundamentally different from sterilised or heavily processed composts designed for uniformity rather than ecology.

 

 

How living compost supports plant and human health

 

Plants grown in biologically active soils tend to:

 

• access nutrients more efficiently

• develop stronger root systems

• show improved resilience to stress

• produce more nutrient-dense food

 

Healthy soils support healthier food systems.

Healthy food systems support healthier communities.

 

Living compost is not just a product.

It is part of a wider regenerative process.

 

 

How this fits into Bristol’s food system

 

Our composting process sits within a local, circular system:

 

Food waste → compost → soil → food → community

 

By keeping this loop local, we rebuild soils and support food growing across Bristol, from gardens and allotments to our two-acre food forest market garden.

 

This is regeneration at city scale, built from everyday actions.

 

 

Want to see it in action?

 

Living compost is one part of the wider Generation Soil project.

 

You can:

 

• join the Bristol Living Compost Project

• visit the Food Forest Market Garden

• learn through workshops and education

• use living compost in your own growing space

 

👉 Explore how to get involved

 

 

Frequently Asked Questions

​

Does living compost smell?

 

Properly made living compost should smell earthy, not unpleasant.

 

Fermentation prevents rotting early on, and aerobic composting ensures oxygen-loving microbes dominate later stages. Strong smells indicate something has gone wrong.

 

 

Is bokashi composting safe?

 

Yes. Bokashi fermentation uses beneficial microorganisms to suppress pathogens and stabilise food waste.

 

When followed by aerobic composting and maturation, the process produces safe, stable compost suitable for gardens and growing spaces.

 

 

How is this different from council food waste processing?

 

Most council food waste is processed through large-scale anaerobic digestion or industrial composting, often far from where the waste was produced.

 

Our approach keeps food waste local, prioritises soil biology, and returns compost directly to Bristol soils. The goal is regeneration, not disposal.

 

 

Is your compost sterilised?

 

No.

 

We do not sterilise compost because sterilisation removes both harmful and beneficial organisms. Our process supports diverse microbial life through fermentation, composting, and maturation.

 

 

Can I use living compost in pots and small gardens?

 

Yes. Living compost is suitable for gardens, allotments, raised beds, pots, and urban growing spaces.

 

It can be used as a soil improver, mulch, or component of growing mixes.

 

 

Why don’t you rush the composting process?

 

Living systems take time.

 

Rushing composting leads to unstable material, nutrient loss, and poor microbial balance. We prioritise biology-led timing over speed or volume.

 

 

Is this approach scalable?

 

Our model prioritises many small, local systems over centralised mass processing.

 

We believe decentralised composting builds resilience, quality, and community connection.