Composting coffee grounds

• 09/02/202201/11/2023
• Compost & worms

Story and poster by Golden Brown Tasmania with help from Community Gardens Australia

Three reasons why you should

1. Nitrogen rich

Nitrogen is critical for plant growth and healthy soils! Nitrogen is also a major component in the composting process. Perhaps you have heard of the carbon/nitrogen ratio, also known as balancing Greens and Browns. Used coffee grounds are relatively rich in nitrogen (Greens) and provide the energy needed to turn organic matter into compost.

2. Abundant and free

With 1.3 million coffees sold every day in Australia, coffee is widely used in modern life and produces methane gas in landfill. As a waste product, used coffee grounds exist in abundance. You can freely obtain this great organic resource locally and help to responsibly dispose of it by recycling it back into the soil.

3. Compost accelerator

Adding used coffee grounds give the compost system a nitrogen boost in the form of energy and heat. This boost speeds up the process of decomposition, resulting in a fast-cooking, hot compost and a finished compost product in less time.

A sustained high temperature also helps to reduce potentially dangerous pathogens and kill seeds from any weeds and vegetables.

If you’re looking for a fast-cooking, hot compost recipe you’ve come to the right place! This recipe can be utilised in any size or style of compost system. It is observation and the maintenance of a productive nitrogen/carbon ratio that will give you HOT compost.

HOT COMPOST TIP:
Always err on the side of carbon. If then what we observe is a slow decomposition process and no heat, nitrogen-rich inputs like used coffee-ground are needed. On the other hand, if what we observe is slop and pong, more carbon is needed.

Ingredients

• 1 part previous compost
• 1 part used coffee grounds (nitrogen)
• 1 part fresh grass clippings (nitrogen)
• 2 parts dried leaves & twigs (carbon)
• 2 parts shredded brown paper (carbon)
• 2 parts straw or sawdust (carbon)
• Air and water

Method

1. Set your compost system up in a sunny spot on soil. The sun will help to heat up your compost!!
2. Gather all of your materials from around the house.
3. If possible, back slop the remains of a previous compost to give your new compost a microbial boost
4. Start with a carbon input and create a thick layer of material around 150mm (6 inches) deep. Lightly water.
5. Add a thinner layer of nitrogen material around 80mm (3 inches) deep.
6. Keep alternating inputs and watering your carbon layers until you run out of materials.
7. Put lid on or cover pile with landscaping material or hay to protect it from rain
8. Turn pile 1-2 times a week. Decomposition occurs even if ignored but turning the pile frequently to
   improve aeration will speed up the process.

Find out more about Golden Brown Tasmania

Golden Brown Tasmania is a community composting project. They collect used coffee grounds from businesses and recycle them back into soils around Launceston. Naturally, their obsession with coffee and composting has led us here

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