How to Make Lactobacillus

By / April 11, 2026

Lactobacillus is a beneficial microbe with a wide range of applications—from improving soil health and composting efficiency to supporting animal digestion and natural household cleaning. Creating a LAB (Lactic Acid Bacteria) serum at home is simple, inexpensive, and requires minimal hands-on time—just a bit of patience.

🧪 Materials Needed

  • White rice (or any kind you have on hand)
  • Non-chlorinated water
  • Milk (raw is ideal, but organic whole milk works well too)
  • Molasses or brown sugar
  • Mesh strainer
  • Glass jars
  • Cheesecloth or breathable cloth
  • Rubber bands or mason jar rings

🥣 Step 1: Make a Rice Wash

  1. Fill a clean glass jar about halfway with rice.
  2. Add water to the top and shake or stir vigorously to agitate the rice.
  3. Let the mixture sit for 20 minutes, shaking a few more times as it soaks.
  4. Strain out the liquid—this milky, starch-filled water is the rice wash.
  5. Pour the rice wash into another clean jar, cover the top with cheesecloth, and secure it with a rubber band.
  6. Allow it to sit at room temperature for 4 to 7 days, depending on ambient warmth.

Over time, the liquid will begin to separate into layers. When complete, the jar will show:

  • A foamy, possibly moldy layer on top (discard)
  • A cloudy middle layer (this contains the lactobacillus)
  • Sediment at the bottom (mainly starches and byproducts)

🧫 Step 2: Culture the Lactobacillus

  1. Gently extract the middle layer without disturbing the top and bottom. This is your rice serum.
  2. Transfer it to a larger jar or container, leaving room for expansion.
  3. Mix it with milk at a 1:10 ratio (e.g., 1 cup rice serum to 10 cups milk).
  4. Loosely cover the container (a jar lid resting on top works well—don’t tighten it).
  5. Let it ferment at room temperature for about a week.

During this time, it will separate again:

  • The top layer forms thick curds (proteins, fats, and sugars)
  • The bottom layer will be a yellowish liquid—this is the desired lactobacillus serum

🧈 Step 3: Harvest the Serum

  • Remove the curds by scooping or gently straining through a fine mesh. The curds can be composted, fed to pets, or added to the soil.
  • The remaining liquid is the lactobacillus serum. It can be stored in the refrigerator at this point, or moved on to the next step for preservation.

🍯 Step 4: Stabilize with Molasses

To extend shelf life and maintain potency:

  1. Mix the serum with an equal volume of molasses or brown sugar (e.g., 1 cup serum to 1 cup molasses).
  2. Stir until fully combined.
  3. Store in a sealed jar at room temperature (lasts up to a year) or refrigerate for longer storage.

🧪 Application & Dilution

LAB serum is extremely concentrated and should be diluted before use. A common dilution for garden use is:

  • 1:1000 (1 mL serum per 1 liter of water)
  • Alternatively, mix 1 part LAB concentrate with 20 parts water to make a working solution, then use 1–2 tablespoons per gallon of irrigation water.

The diluted mix can be stored in the fridge and remains viable for weeks or even months.

🌿 How to Use LAB in the Garden

Lactobacillus helps:

  • Break down organic materials (like kelp, fish hydrolysate, or compost teas)
  • Accelerate composting
  • Improve soil biology and structure
  • Enhance nutrient uptake for plants

For example:
To supercharge a kelp tea, add 1–2 tablespoons of LAB per gallon of tea about 24 hours before application. Stir a few times to help introduce oxygen, and allow the bacteria to start pre-digesting nutrients into plant-available forms.

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