Lactic Acid Bacteria, or LAB is a wild fermentation of probiotics that can be used as a soil additive or compost starter. Collecting and propagating your own LAB is easy and much more affordable than purchasing similar products, which can cost as much as $90 USD per gallon!
Step 1: Collect Bacteria
Start by collecting LAB from the air using starchy water. The traditional Korean Natural Farming method is to use rice wash water, but if you don’t cook white rice on a regular basis, a small amount of flour in water works just as well.
Add about 1/2 teaspoon of flour to two cups of water in a wide bowl and cover with a paper towel or clean cloth. Let it set at room temperature for about three days. You’ll know the starter is ready when it smells a little sweet. It’s ok if there are spots floating in the liquid, but you don’t want it to be overgrown with mold.
Step 2: Ferment in Milk
Then you will add the starter to some milk. Lactic acid bacteria out-competes all other microorganisms in milk at room temperature. It’s best to use fresh skim milk or powdered non-fat milk. The fat will float to the top and make farmer’s cheese. Sometimes it’s edible, but it’s usually not very tasty. Add the starter to about half a gallon of non-fat milk, cover with paper or clean cloth, and let it set for about a week.
You’ll know it’s done when the cheese on top is solid like feta. The liquid underneath should be clear and yellowish, not milky. Skim the cheese off the top of the liquid. If you want to use the LAB fresh, put the liquid in a sealed container in the refrigerator and use it within two weeks. If you want it to last longer, you can stabilize the bacteria with brown sugar.
Step 3: Stabilize with Brown Sugar
To stabilize the LAB, weigh the liquid and then weigh out an equal amount of brown sugar. Dissolve the brown sugar in the liquid and store it in a sealed container at room temperature. Check on the mixture each of the next two or three days and stir it to make sure the sugar is saturating the liquid. There should be a thin layer of sugar on the bottom of the container, even after stirring it thoroughly multiple times. If it smells like vinegar or alcohol or has a lot of bubbles, it is not stabilizing and needs more sugar.
Step 4: Dilute and Use LAB
To use LAB, dissolve it in water at a ratio of 1:1000, or about one teaspoon per gallon, and use it to water your plants or compost pile. I add it to a bucket full of food scraps, seal the bucket, and let the food scraps ferment for two to four weeks before I mix it into my compost pile. This makes the food scraps less appealing to animals and composts much faster.
Links to More Information
What are Effective Microorganisms? https://www.permaculturenews.org/2016/01/19/what-are-effective-microorganisms/
Chris Trump, Lactic Acid Bacteria https://christrump.com/inputs/lactic-acid-bacteria/
