What’s Brewing is a podcast all about compost tea hosted by Troy Hinke.
Troy Hinke served as Rodale’s Compost Research Specialist alongside the founder of Soil Foodweb Inc., Dr. Elaine Ingham. Troy now runs Living Roots Compost Tea, where he offers several services including consultations, compost sprays, and compost brewing, among others.
Episode four of a 10-episode series on compost teas, host Troy Hinke talks about the materials we need to successfully brew high-quality compost tea.
What We Need to Brew Compost Tea (01:07)
Simply put, the materials needed to be able to brew compost tea are a clean container, clean water, finished compost or vermicast, a brew bag, an air pump or air blower or air hose, and then finally, foods for microorganisms.
Container. The container can be anywhere from a simple 1 to 5-gallon bucket to large, commercial conical brewers.
Water. Rainwater works best for brewing compost tea. Pondwater is discouraged as it is stagnant water, which means it’s already populated with anaerobic bacteria. Creek water is also discouraged since we never fully know what’s upstream from us. Most people will use well water or municipal water, which needs to be treated to get rid of the microbe-killing chlorine.
Finished compost and/or vermicast. This will be the source of the compost tea’s microorganisms. It’s good to use compost or vermicast of varying ages to get the most diverse set of microorganisms possible.
Brew bag. Smaller brews up to five gallons that don’t really use sprayers can skip having to use a brew bag. But for larger brews, a brew bag is a must. The brew bag, for smaller brews, can be as simple as a paint strainer bag, but for larger brews, a heavier-duty commercial-type mesh bag will work great.
Air pumps and air blowers. Smaller brews up to 100 gallons can make use of air pumps, which cost from $20-70, while brews larger than that will need air blowers, which go up to over $700.
“The whole idea behind compost tea is that we’re extracting these microorganisms from the surface of the compost, and then we’re adding foods for the microorganisms to get them to eat and reproduce to very high populations.”Troy Hinke
Microbial food. The best and possibly only food for bacteria are unsulfured blackstrap molasses. As for fungi, there are a number of foods to use such as humic acid, fish hydrolysate, kelp, feather meal, and steel-cut oats.
Protozoan Infusion (15:44)
As previously mentioned in the episode on the soil food web, bacteria and fungi store nutrients in their bodies, and predators are needed to release those nutrients into plant-available forms. One of those predators are protozoans, which you can also add into your compost tea brew.
Adding a small handful of straw in the last 12 hours of a five-gallon brew will provide a good amount of protozoans in the brew.
Keep the Equipment Clean (17:35)
Lastly, while it may sound obvious, keeping the brewer clean should be a priority. Otherwise, a layer of biofilm can form on the surface where anerobic microorganisms can breed and prevent you from successfully brewing quality compost tea that is high in beneficial biology. The same goes for the brew bag, which has sat in the water with the fish hydrolysate, humic acid, and possibly even molasses. The brew bag can be soaked in water for a few hours before scrubbing the entire thing clean and ready for the next brew.