Amelia Braddick sat down with Will Crossley, co-founder of Local Origin to discuss urban farming and how to compost from home.
Q. How did you both get into composting and urban farming?
A. We have both enjoyed gardening and growing plants at home for many years whilst living in London. During this time, we became more aware of the challenges of growing healthy plants in urban environments with the constraints of space and light especially.
We started experimenting with composting at home to feed our plants, but also to make use of our food waste at home. The idea for Local Origin began around 2 and 1/2 years ago, when Dan and I – who were both composting and growing food at home at the time – took inspiration from a French organisation named ‘Les Alchemistes’ that provides food waste composting services for households. We discussed the need for a decentralised composting service in London and decided that we would like to establish a company that tackles the food waste issue and offers a sustainable urban agriculture model.
For us, the idea meant turning our hobbies into our work and taking an opportunity to contribute to combatting issues of food waste such as emissions, food security, soil health and strengthening local communities.
Q. Can you provide more details about the process of turning food waste into compost?
A. Our current composting site on Spitalfields Estate uses two 200 litre Hot Bin Composters for aerobic composting, and one 1500 litre Wormery for vermicomposting.
We receive food waste (source of nitrogen) from the restaurants and food vendors located in Spitalfields and mix it with cardboard (as a source of carbon) and bulking agent (either woodchip, woody garden waste or pvc piping which we reuse), before adding it to the Hot Bin Composters. The food waste spends about 2 – 4 weeks (during which time is regularly turned and new waste is added) in the Hot Bin Composters at 60 degrees centigrade (or higher) we take it out and add it to the Wormery.
In the Hot Bins, the waste reaches temperatures that kill off weeds, seeds and pathogens and is broken down, so it is no longer recognisable as food waste – this part of the process is our pre-composting stage.
Once the pre-compost is in the Wormery, the worms begin to eat it which further breaks down the material into what is known as worm castings (vermicompost). This process is particularly beneficial because as the material passes through the worms it is inoculated with microorganisms, creating a living compost.
This final product needs some time to mature, following which is ready to use as a growing medium containing nutrients in ready to use form live with bacteria, fungi and protozoa that are beneficial for plant growth and health.
Q. How many restaurants and hospitality vendors in the area have donated their food waste to this initiative?
A. We currently service the restaurants within Spitalfields Market. We take food waste from the market once a week. In conjunction with the pre-existing waste management service at Spitalfields, we are based by their waste collection and recycling unit, so we request for a food bin and cardboard to be left out for us at our site. This means that in any week, we might have a food bin from one of the many restaurants within Spitalfields Estate and we process approximately 8kg of food waste each week.
We hope to expand our capacity and subsequently be able to process more food waste – eventually using a fleet of electric bikes to collect food waste from households and process their waste at local sites spaced across London.
Q. How do you ensure the quality and nutrient content of the compost?
A. Consistency in reaching temperatures above 60 in our pre-composting phase means that we are composting aerobically (using aerobic bacteria) and killing off anything unwanted or that can be harmful to plants/animals in our final compost product, including weeds, seeds, anaerobic bacteria and pathogens.
To ensure we are getting the right nutrients in our final compost product we ensure we process the right amount of nitrogen rich waste (for example, veg scraps) and carbon-rich waste (for example wood chip or cardboard). The nitrogen rich waste provides the nutrients.
Additionally, we put measures in place to ensure that the compost is ‘living’ including our secondary phase which involves worms eating the pre-composted material. When the worms eat the pre-composted material, it gets inoculated with their gut bacteria, which then live in the composted material. These bacteria are essential to plants getting the nutrients they need, as they mine the minerals and nutrients in the soil, resulting them being readily available for plant consumption.
Finally, we add some garden waste from the Spitalfields Estate, which contains a lot of living organisms, which increases the biodiversity of our compost product and hence its overall health.
Q. What were the challenges you faced when setting up your composting and urban farming operations in Spitalfields, and how did you overcome them?
A. Some of the challenges include ensuring that ratios of carbon, nitrogen and bulking agent are correct. If the balance is not right, then the compost can be anaerobic, meaning that it smells bad and unwanted bacteria live in the compost.
Additionally, in the wormery, conditions need to be right for the worms to live healthily, want to stay there, eat the pre-compost and ultimately reproduce. To monitor the conditions of both our operations, we take regular readings of various measures including temperature and moisture levels.
Efficiency is another challenge, ultimately, composting is a natural process and whilst it can be sped up and enhanced through various techniques, it does need a certain amount of time, if you want the final product to do all the things we want it to (linked to our aims).
Q. Do you have any advice for people who hope to be more eco-friendly and prevent food waste at home?
A. You can make your own wormery quite easily with a few lidded buckets, a drill and some cardboard – just make sure the worms aren’t somewhere they will overheat.
You can start adding veg and fruit scraps and build in more waste from there. Additionally, a bokashi compost bin is a great way to get into composting, bokashi contains microbes that speed up the process and means all food waste can be processed; it can be done in a relatively small space too – you can buy a pre-made set up or DIY if you’re so
inclined.
The nice thing about combining composting with growing is that you can test out your product. After you have tried composting some food waste, you can add the compost you’ve created to some pots and then plant some vegetable seeds to see what you can grow.
There is loads of learning to be done on YouTube as well, great free guides and resources which take you through it step by step. I would encourage everyone to try it, don’t be put off by the thought of ‘smelly food waste’ it doesn’t have to be that way and you can have such an impact preventing waste and subsequent emissions – your very own climate change activism from home!
Q. What do you think about the government’s approach to preventing food waste?
A. Whilst there are some measures in place to reduce food waste, there is no consistency across the whole country with regards to food waste collection. As a result, lots of food waste ends up in landfills where it releases harmful greenhouse gas emissions. Lots of the great food waste reduction work nationally is being done by independent organisations tackling food waste at different levels, including food recovery, food waste composting, food redistribution etc.
National strategy, which is properly communicated, coupled with the necessary infrastructure is needed to tackle the scale of the food waste issue; lots of inspiration can be taken from small, independent and localised solutions popping up in communities where people are taking their own action.
Large amounts of food waste are directed to anaerobic digestors for the creation of gas. Whilst this is much better than the same food waste ending up in landfill, our preference is to create living soil as this puts food waste to a use that increases food security, reduces greenhouse gas emissions, strengthens soil health and biodiversity and leads to healthier food, all of which benefit people and planet together.
Q. Do you have any plans to expand your compost business to other food markets in London?
A. We do yes! We are currently in talks with a neighbour to Spitalfields; a site that houses multiple restaurants, a pub, a salad bar and a canteen to see if we can design and establish a waste management and urban farming system that would enable us to process their food waste and grow crops for their various food outlets.
As our model is a cyclical, hyper-local one by design, we want to establish composting and farming sites at a range of markets and estates to process their food waste and grow produce for their needs.
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