Airlift Tea Brewer

More advanced techniques

If you decide you are going to make more than an occasional batch of AACT, I encourage you to consider making a brewer that's more robust and has more airflow. You'll get even better results, and with a modification I'll show you in a second you can make anything from 5 to 50 gallon batches with the same equipment!

Airlift brewing offers greater airflow and oxygen, more agitation which solubilizes more microbes, and "turns over" the entire volume of tea constantly in the vessel from bottom to top. Generally one needs at least 0.05 to .08 cubic feet per minute of air flow, per gallon of batch size.

This gent has one of the better summaries so rather than duplicate his work I'll let you get the gist from him. The only modifications that I make are these:

  • One is a way to anchor the top in place. The vigor of the aeration can really bop this thing around! I just use a bungee but someday I think I'll bridge it with a scrap of board and a clip to grab the PVC.
  • The other is that I have two of the upright sections, one for a 5-gallon bucket height and another for the 40 and the 50-gallon big trash can batches. The pump has PLENTY of power for that big a lift and batch size. You'll also want a longer braided air hose, mine's about eight feet so I can set it out of the way.

Here is mine in 5-gallon configuration:

bubbler video .mp4

And in 50-gallon with a taller riser:

20190421_123738.mp4

As you can see, there are a few ways to run these. For most outdoor use I don't use a "tea bag": as long as the particle sizes are smaller than an inch they run right up through the airlift and just cycle through. If it'll be for indoor houseplants or other uses where some debris coming out the watering can isn't desirable, I will either use a strainer or a tea bag. But mostly I don't use a bag: part of what gets microbes into solution (freed from their attachment to the compost particles) is the agitation of moving around in the brewing vessel. So containing them in a bag does limit that action somewhat. If you use a bag just don't pack the vermicast in tightly: use a bigger bag so it can float around and agitate freely.

The great part about an airlift is that there's no aeration stone to eventually clog and reduce flow. The pipes can friction-fit together so you can clean easily between batches (remember cleanliness is SUPER important for AACT brewing, get that biofilm outta there!).

The only kind of specialized part for this build is the pump, everything else is a local hardware store purchase. I use this model.



It's around $43 so a modest investment but the air flow is tremendous; I had it from a previous project but it has become indispensable to me. Anything with comparable air flow and pressure should be just fine.