Muck Pit Lifecycle

[SaltyStaves]

My pit has been through a season and now that Spring has arrived (down) here, I'm kicking it off again.
Hopefully I've learned a few lessons. This seems like a good time to document what worked and where it failed...

It began last year (summer) when a molasses ferment developed an acetic acid infection. I didn't want to throw it all out, as it was always destined to be fresh dunder, but it also created a storage problem. It is not the type of thing you want hanging around your future washes, so I needed it out of the way.

I had thought about making an outdoor pit and this was the perfect motivation.
Found a stainless steel wash basin (44L), capped the drain and insulated it with Rock wool.

MuckPit_top.jpg

The pit was then partially buried in an outdoor spot with good sun exposure.
I made a cover with some untreated timber and loosely covered with tempered glass which allows for some airflow.
The pit was filled with the acetic infected wash.

As this was already highly acidic, I wasn't concerned about keeping my eye on it.
It sat in the pit for 5 weeks and hardly changed. It lost some water through evaporation and the vinegar aroma slowly started changed back to molasses.

Muck Pit Slick.jpg

The pit was racked out and dried and the bottom lined with Marl clay.

Pit clay2.jpg

This holds lime for slow release and is a substrate layer which solids like Lees and plant matter etc can settle on. Without this, its easier to disturb these solids when removing or adding new liquid to the pit.

I installed a new cover made from rough sawn untreated and silvered pine. The timber extends into the liquid. Some bacteria need to colonize on solid matter like wood. A slickwalled stainless steel or plastic container doesn't facilitate this at all.

Once the clay had dried (several days), the pit was filled again but with a combination of fresh dunder and the acetic acid infected wash. This was then pH adjusted with hydrated lime.
While waiting to fill the pit, I had cultivating a butyric acid starter in a 4L jar. This was cultured with a dirty potato and developed in a sealed and dark room.

Potato Jar1.jpg

Once a decent pellicle had formed, this was pitched into the pit and left.

Potato Jar2.jpg

Potato Jar3.jpg