Trial: Unmodified PP5 Lid G2G

Trial Log

Project Goal: Determine if the initial volume of air trapped inside a tightly sealed jar is sufficient for mycelium to reach 100% colonization without any further gas exchange.

Start Date: 5-20-2026

Method:

1. Grains sterilized using the 1/4 turn method.
2. Jars were sealed tightly immediately after cooling.
3. Lids were opened briefly in a sterile field to perform the G2G transfer.
4. Lids were closed tightly again for the duration of the colonization.

5-24-2026: Performed a Break and Shake (B&S) on both the quart jar (unmodified lid) and the 1/2 gallon jar (filter disk lid).

5-26-2026: I decided to "burp" the unvented jar by opening it in front of my flow hood for about 15-20 seconds to provide fresh air exchange and test if stagnant air was the issue. Growth speed has definitely improved since then!

5-28-2026 (Update): I've spotted a reddish growth in both the vented and unvented jars. Looking back, this contamination was actually already visible in the 5-26 photo for the vented jar if you zoom in, even though it was hard to see in person at the time; it wasn't visible in the unvented jar until now. I suspect this originated from the old agar plate I used for the inoculation—a good reminder that multi-transfer cleanup is essential for old cultures! The mycelium appears to be winning the battle, so I'll run this to bulk on a small scale as an experiment to see if it can outcompete the contamination. In the meantime, I'm going back to agar to clean up this cultigen with multiple transfers before I use it again.

5-29-2026 (Update): Despite the reddish contamination we spotted earlier, both jars are showing surprisingly good mycelial growth. It seems the mycelium is putting up a good fight! I'm continuing to monitor them closely.

5-30-2026 (Update): Just a quick status update—growth is continuing steadily in both jars. The resilience of this cultigen is pretty impressive given the contamination it's dealing with.

Progress Photos

3 days post-transfer (5-23-2026).

Side-by-side: Filter disk (left) vs Unmodified lid (right) after B&S (5-26-2026).

Reddish contamination in the grain jar (5-27-2026).

Growth progress despite contamination (5-28-2026).

Continued growth (5-30-2026).

Next Steps

If the quart jar reaches 100% colonization while tightly sealed, I will scale this trial up to a **1/2 gallon jar** to see if the air-to-grain ratio in a larger container remains viable for full colonization.