Technology
Lactic acid fermentation, at the scale of a town
LAF stands for lactic acid fermentation. It is the process behind sauerkraut, kimchi and silage. We use it to stabilize food waste and turn it into something soil can use.
What goes in
Three materials, all of them local and all of them currently treated as waste.
| Input | Where it comes from | What it does |
|---|---|---|
| Food waste | Restaurants, grocers, food processors | Supplies the nutrients and the sugars that the bacteria feed on |
| Wood chips | Local wood waste | Soak up liquid, add carbon and give the mix structure |
| Acid whey | Dairies and cheesemakers | Brings lactic acid bacteria and gets the fermentation started |
What happens in the container
Seal
The mix is closed up with the air kept out. Nothing is turned, aerated or left open to the weather.
Sour
Lactic acid bacteria convert sugars into lactic acid. The mix turns acidic, the way cabbage does on its way to sauerkraut.
Hold
That acidity keeps rot at bay. The material is preserved instead of putrefying, which is why there is no smell.
Return
The fermented material is worked into soil, where soil life finishes breaking it down and crops take up the nutrients.
Why ferment instead of haul
Fermenting in a sealed container solves the problems that make food waste hard to handle close to where people live and work.
No odors
The container stays closed from the day it is filled until the material is ready.
No runoff
Liquid stays in the mix, held by the wood chips, instead of draining onto the ground.
Nutrients stay local
What comes out goes onto North Coast soil instead of into a distant landfill.
Fewer truck miles
Short local trips replace long hauls out of the region, and less food rots into methane.
Tested in the ground
We have run the process in the field and planted into the result. The photo on our home page shows one bed with two rows, one amended with LAF and one not.
We are in early conversations with CalRecycle about how this fits into the state's organics framework.