How to Make Lactobacillus Serum (LAB Serum)

Lactobacillus Serum, also known as LAB Serum, is the workhouse of beneficial bacteria. Learn how to make it at home for use in home, garden, farm and more.

Lactobacillus Serum, also known as LAB Serum, is incredibly easy to make at home. With a few simple ingredients and time you can have a powerful tool for your home, garden and farm.

Lactobacillus is the workhorse of beneficial bacteria that can be used for a variety of applications. Use it to clean a clogged drain, rid smells and control orders, enrich your garden and aid in chicken/pig/beef  farming. Once made, it can be diluted accordingly for use in home or garden.

How to Make Lactobacillus Serum (LAB)

To make LAB, you’ll want to collect bacteria from the air using water that has been used to rinse rice.

Any rice can be used to make LAB serum. I used organic jasmine rice but you could use brown rice too.  Put your rice in a pot with warm water,  mix the rice around and then drain the water into a quart-size canning jar.

That “rice wash” water is now rich in carbohydrates (you can’t see it, but it is). That liquid will attract microbes from the air  – one of them lactobacillus.  Cover the jar with a piece of cotton fabric or cheesecloth to allow it breathing room.

Push to the rear of your kitchen counter, in a dark closet or outside on the back porch anywhere from a couple days to a week.

When is it ready?

After one week (or 5 days if you are in a warmer climate),  the rice wash will have a light layer on the top and smell a little sour.  When it’s done, you’ll see three layers:

• Top Layer: Floating carbs left from the fermentation
• Middle Layer:  Lactic acid + other bacteria (which is what we are going to use to make this LAB serum)
• Bottom Layer: Starches – which are a byproduct of fermentation,  we’ll discard this

Use a siphon (a turkey baster works well) to siphon 1 C. of the middle layer out and into a clean, gallon-size glass jar.  This  layer has the highest concentration of lactic acid bacteria.

Mix that single cup of rice wash with 10 parts (cups) milk. Adding lactose to the wash will prevent other microbes from proliferating –  leaving only lactobacillus.

(Note: the best milk to use is raw, unpasteurized milk. However, if you are in an area that you cannot obtain raw milk, then use whatever is available as long as it has lactose.)

Combine with Milk

Mix the rice wash with the milk, then push the container to the rear of the counter, or put it back in a dark closet/pantry. Keep the mixture as anaerobic as possible. Use a fermenting lid or keep the container sealed. If you keep a lid on the container you’ll want to loosen it each day to burp the LAB as it grows.

The container must also not be completely filled or it might bubble through the valve. Allow the mixture to sit for at least 7 days. You will see it transform during that time. 

First, it will start off as a milky mixture. Then, the milk will start to curdle as it enriches with the lactic acid from milk fermentation.

After 7-10 days,  the mixture will separate into two layers. The layer on top is a thick mass of curds — an excellent food that can be enjoyed as cheese (yes, by you!)  It’s enriched with microbes and nutrients.

Feed it to your compost pile, animals or wrap in cheesecloth to dry out for a few days. Then enjoy with a little salt.

Extracting the Whey

Once you have two distinct layers, your goal is to grab the yellow-colored whey. Lift out the top layer from the  jar, and set aside. Then run the yellowish layer of serum (whey) through a cheesecloth into a clean jar. That whey can be kept in the fridge for up to 2  weeks.

To preserve the serum for a longer period of time, add an equal amount of blackstrap molasses or brown sugar, and stir well. Store at room temperature for up to 12 months.

Feed and Dilute your LAB  Serum

LAB Serum (also known as Lactobacillus Serum) can be used for home, garden and even agricultural use. By feeding your LAB molasses or brown sugar (from the previous step), you will have it ready whenever you need it.

Before using LAB for home, garden, agricultural or personal use, you will want to dilute the mixture.  

Dilution ration: 1/500 ~ or 2 Tablespoons per gallon (128 oz), or higher concentrations for odor control.

Using Lactobacillus Serum for Home, Garden or Agriculture

Odor Reducer: Once diluted, apply in areas that need greater odor control or a reduction of odors – animal pens, dog crates, kennels or litter box trays.

Garden Use: 2 Tbsp per gallon of water and used every 3-4 weeks as a soil drench. Or used topically as a foliar spray.  By using  as a soil drench, you are helping to increase the efficiency of nutrients to the plant.

Home Use: Clean clogged drains by pouring the diluted mixture down a struggling drain. If possible, allow the mixture to sit in the drain overnight to work for several hours. 

Farm Use: Once diluted, spray animal bedding to prevent/reduce odor and illness. Moisten, but do not over-saturate bedding.  Dry climates may require a greater saturation than humid climates, just make sure you mix well to distribute evenly.

Animals:  LAB can be used to aid in digestion. Microorganisms in LAB help digest food, therefore better absorption of nutrients and resistance to disease. LAB helps to prevent harmful bacteria in food/water that animals consume. At the same time it greatly enhances their intestinal gut flora. Add just enough to be effective – once the LAB is diluted (as noted above) soak the feed in the solution for several days.

By allowing the feed to soak, the food is literally pre-digested when it gets to the animals.

Humans: mix 1-2 teaspoons with one cup of cool water to re-establish proper gut health and promote internal healing.

LAB Serum can also be used in bokashi composting, fish farming and more. Once the serum is done fermenting, you will want to feed it with equal parts molasses or brown sugar. Then store in a cool, dark area.

What do I do with the curd?

Don’t toss the curd!  Keep the curd – if you aren’t interested in wrapping up to dry out a bit, then use in your compost. Or you can also feed to your animals. The top layer of curd is rich in probiotics and nutrients that are wonderful for digestive health.

Simply keep the curd tucked away in a separate jar so you have it ready when you determine what you would like to use it for.

Things to Consider

LAB Serum, once made, is best kept in a 5-gallon bucket that has been modified with a spigot.  If you are  in a moderate climate, the serum can be kept in your garage or garden area provided you have fed the whey with equal amounts of molasses or brown sugar.

Those sugars will give the serum something to feed on  over time. The bucket with a spigot is an easier way to add a small amount to a spray bottle to dilute with water for use as a foliar spray. Or use a higher ratio of LAB when diluting to spray areas that need more help (ie. odor control).