This post explains how to make your own EM. This can multiply your EM exponentially for cost effectiveness. For an introduction to what EM is, click here
1. First, you must establish a mother culture. The one I'd recommend using is called ProBio Balance, made by students of the horticulturist who originated EM.
2. Molasses. Purchase some unsulfured blackstrap molasses from me or your local grocery store. Unsulfured is important because sulfur is used in molasses to kill microorganisms while they are multiplying. Blackstrap molasses is beneficial because it is low in sugar and high in nutrients.
3. The container. Locate a plastic container with a tight-fitting lid, such as a water or soda bottle. Any size container will suffice, but I usually make batches in 1-cup, 1-quart, or 1-gallon sizes.
4. Water. Fill the bottle halfway with hot water – not boiling, but hot enough for a bath. If you have access to spring water or dechlorinated water, that's ideal, but – the microbes may even clean up some of the chlorination if the water isn't super chlorinated because some of the microbes help with detoxification.
5. Add the molasses and mix well. Add 5% of the container's volume of unsulfured blackstrap molasses to the water. The heat, combined with your swishing (which you can now begin), will help dissolve it.
6. Food and nutrition. This is an optional step, but it will provide additional nutrients. Add sea salt, kelp powder, or sea minerals - 0.1 percent of the volume of each to the container.
7. Incorporate the mother culture. Add EM1 or ProBio Balance - 5% of the container's volume.
8. Add water. Fill the remaining space in the bottle up with warm water.
9. Shake. Gently but firmly, as if you're a playing shaker in a lively song.
10. Warmth. It works best in temperatures ranging from 80 to 100 degrees Fahrenheit, so place it in the warmest part of your home. It should work fine at 70°F, but it will take much longer.
11. Leave it with the cap on tightly (air tight). It takes at least a week to be ready to use, and 2-4 weeks to be really good (or 6-8 weeks if it isn't kept warm
12. You'll eventually need to 'burp' it on a daily basis by unscrewing and screwing the lid back on to release the gases that will begin to form after a few days to one week.
13. Put it to the test. You can get a sense of when it's done by smell and taste after a while, but you may also do a test with pH paper (or a pH meter) that gives readings in the 2.5-4 range. Anything between 3.8 and 2.7 is acceptable, with 3.0-3.5 being ideal. 3.8 and higher are not acceptable.
14. Make use of it. Farmers spray it on plants, soil, and compost once a month at a rate of 1/2 cup per 1000 square feet, mixed with at least 8 gallons of water (a 1:250 ratio). If you used food grade materials in your preparation you may also drink a shot per day or a tablespoon with every meal to support your overall health and wellness.
15. Keep it somewhere safe. At room temperature, not in direct sunlight, but also not in complete darkness, as it appears to benefit from a little indirect light. The mother culture has a 'best by,' or expiration date, but it can last for another year.
Your homemade activation is most effective within the first month after the pH drops below 3.8, but it can be stored for months afterwards. If you make more than one bottle, once the activation is complete, you can use one bottle to fill the rest to the brim so that they can be stored without air, and then just use that bottle first. A small amount of air is acceptable during fermentation, but not during storage if you want it to last a long time.
Optional bonus step: Share this knowledge with others who might benefit! (optional, but a good idea)