Behind the core, social business operations of Mandela Grocery and Red Bay Coffee are tiny rooms. Tiny rooms with large trash cans. This is where this story begins – at the end where everything is finished … or is it?
It is called green waste because it is almost alive and is rich in nitrogen. I think of it as green waste because it goes into the green can. At the back room in Mandela Grocery, the source of green waste is fresh produce clippings, overripe fruity things and left over food from those that like to get their food, sit down and eat.
The green waste from Mandela Grocery is nothing like green even though it goes into the big green garbage can lined with a black plastic bag. The black bags are usually reused as fresh produce comes to the store in them. I use my wheelbarrow to pick up a load as shown below once or twice a week. It makes me feel like a professional as get to wear my urban farming boots.
It’s organic, so many varieties of fresh produce, so many colors, textures, shapes, and scents – I think I should start referring to it as rainbow waste. You can tell a lot about people from their waste, Mandela Grocery customers consume high-quality produce.
I really like the smell of freshly roasted coffee.
Red Bay Coffee’s garbage smells of fresh coffee. A by-product of roasting coffee is chaff. It’s fluffy and light floating during the roasting process, collecting in filters bags above the hot air. It is rich in nitrogen, as are the grounds and coffee bean. I use chaff for bedding and compost piles. I also get coffee grinds and coffee beans left in burlap sacks the free trade coffee from small scale farmers is imported in. I refer to Red Bay Coffee waste as black waste because of the dark black color of the coffee grinds. It is actually a very green waste rich in nitrogen and goodness.
Coffee beans, coffee grinds and coffee chaff are shown below. The chaff is the outer skin of the dry bean whereas the grinds are the by-product of brewing coffee. The bean is half of the hard pit you find inside a coffee berry.
I get coffee waste in biodegradable bags in garbage cans and lots of burlap sacks for good measure. Coffee is shipped in the dark green plastic bags inside burlap sacks for protection from moisture. I get lots of these too that I reuse for garbage and packaging compost. I get my coffee waste in bulk once a month unlike twice a week from Mandela Grocery.
I derive intense pleasure upcycling and zero wasting materials that would normally be undesirable. The contents of the waste products from Mandela Grocery or Red Bay Coffee on their own would be a green waste. But when I mix this with the brown waste from my chicken coop and rabbit hutch then soak everything with water, life starts creating black gold.
A new generation of chicks is shown below.
I refer to my waste as brown waste because of the hay color. In reality, it is a combination of brown waste that is also very rich in nitrogen from the chicken and rabbits waste. The terms brown waste usually refers to waste rich in Carbon such as straw or dry hay.
I should refer to the rabbits waste as pink waste considering it costs a carrot to pet them and there is no shortage of petters
The compost bins are about 4′ square and 3.5′ tall made from reused pallets. The piles are layered alternating the green materials, brown materials and inoculants until it is full then it is jump-started by watering with water from the aquaponics fish tank.
The following are typical inoculates used in the compost pile.
The folks at Mandela Grocery normally call me when the green waste can is full once either once or twice a week. I then add this green waste and spread it out as a layer in my compost bin.
This is covered with a thin layer of coffee waste. Coffee gives the compost an acidic edge which tomatoes and chilli plants like. It is rich in nitrogen and has numerous trace elements including magnesium, copper, phosphorous, potassium, etc. Further, bugs don’t like diterpenes and caffeine, I think it gives them jitters. Nonetheless, I use it in moderation.
This is followed by a thin layer of old compost. The old compost acts as an inoculant for microbes and is full of composting worms.
I further inoculate this layer with fungi spores and amend using humates.
Typical commercial fungi and humates I use for inoculation and amendments are shown above and below sprinkled into the compost layer.
In this case, the commercial fungi strands come from Oregon, there is no guarantee they will colonize a different environment like West Oakland. So I scavenge for local strains and get samples of rich soils from local forests that friends bring me when they go hiking or visitors from the countryside to additionally inoculating the compost piles with a variety of local microbes and local fungi. A sample of cellulose-eating fungi strands I found on a stump by the streetside and seeded the compost pile with is shown below.
Then I add a layer of hay used as bedding in the chicken coop and rabbit hutch over inoculation layer.
I usually get a copy of the Oakland Post and East Bay Express free papers when I pick up waste at Mandela Grocery, then cover the pile after to prevent bugs breeding after browsing through them. The papers just carbon in.
Normally I keep a burlap on the topmost layer to keep the pile from drying out. And a thermometer is added to monitor the temperature of the pile as shown below.
The layering process is repeated until the bin is full. Water is then added to start the composting process. In this case, our bin is so healthy of microbes that the pile is already hot before I formally start composting as shown by the thermometer below. This is a healthy sign, the hot heat kills pathogens and weed seeds in the compost materials.
After seeding with fungi strands and spores, different kinds of mushrooms start to growing in the compost pile within a day or two. This is a good sign for this particular bunch of compost pile as it is desired to have high fungal bacteria ratios.
We use a 4-bin rapid composting system comprising of two 2-bin systems. It is similar to a 3-bin composting system, but with an extra bin. Microbe activity is high in the pile when they are reproducing which is directly observed using the thermometer as the temperature soars. When the process slows down, the pile cools down. Physically turning the pile again introduces oxygen which starts bacterial activity until all bio-available food in the compost is finished. The turning is repeated until all the waste is broken down and the compost pile is ready (chemically stable).
A finished pile of compost looks like rich black soil and smells like fresh earth.
The last of the last compost pile currently in use is shown below
The process of composting has three stages, a warm mesophile stage when microbe colonies are building, thermophile when the pile gets really hot that is largely enzyme-driven and a cooling stage when the pile stabilizes chemically.
When the temperature of the pile stops raising after turning the pile over, the compost is stable and ready for use. I like to test at this point as unstable compost can easily become phytotoxic. I observe it, looking at it intensely, touching its texture and smelling its scent. I also use a microscope to identify microorganisms and colormetric tests for chemical stability. I start by taking a sample in a test tube from the compost pile.
I then add dechlorinated water and agitate the mixture gently for a minute to release the bacteria and other organisms from the aggregate.
I then take a sample and place a drop on the microscope slide and add a slip cover.
Then I use a microscope to observe the sample at 40x-1000x. And 45 minutes later my eyes are still stuck to the compound lens – I just love seeing things I can’t see.
I can try to describe what I saw in this heathy compost but it would not do justice. I really need a microscope with a camera. There were a number of bacterium eating unsegmented nematode, numerous bacteria rods wiggling and spheres tumbling around, various forms of protozoa flagulating and oozing, several fungi strands, arthropods, mineral crystals, aggregate clumps etc. all in that one tiny drop of compost.
Besides pH, I am never sure what I am looking at using a colormetric test kit. So, I normally cover the sample overnight forcing it to go anaerobic, then I take more reading for a couple of days. If the compost is stable the test results will be similar. If the compost is ready I use it for plants or compost tea.
Compost channels water when I use on it’s on in a flowering pot, so I mix it with perlite which helps it to retain moisture in growing containers.
I used to struggle with getting seeds germinated or seedlings in time for the growing season. A benefit of green waste from Mandela Grocery is many tough crops germinate in the compost piles. I rescue anything that looks interesting when it germinates in the piles, but I can’t tell what is growing until late summer when it is fruiting season.
But when the choice is mine, I like interactive plants like the Carolina Reaper seedling I started and hope to transfer to the larger container below.
Reapers, Scorpions, Ghosts and 7-Pots, soon I will confidently be able to say that I have the hottest garden in the Bay Area – it will be easy to physically prove.
Do you need fresh compost? I am not going to say anything about the compost in bags at the store or how dead it appears under a microscope.