Trial: Unmodified PP5 Lid G2G
Testing the limits of simplicity: Performing a Grain to Grain (G2G) transfer using standard, unmodified PP5 plastic lids.
Trial 1: Tightly Sealed (Status: BUST)
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
Progress Log:
3 days post-transfer (5-23-2026).
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!
Side-by-side: Filter disk (left) vs Unmodified lid (right) after B&S (5-26-2026).
5-28-2026 (Update): Reddish growth spotted in both jars. My suspicion is the old agar plate used for inoculation. The mycelium is fighting it.
Reddish contamination in the grain jar (5-27-2026).
5-30-2026 (Update): Growth is continuing steadily despite the contamination.
Continued growth (5-30-2026).
6-5-2026 (Update): Vented jar leading, unvented still pushing toward completion. Both dealing with yeast.
Vented (left) vs Unvented (right) comparison (2026-06-05).
6-10-2026 (Update): Vented jar looks great and finished. Unvented quart jar still not completely colonized. Lack of ventilation has definitely slowed it down considerably.
The difference in colonization speed is now very apparent (2026-06-10).
6-16-2026 (Final Update): Calling it a bust. The unvented lid is still not fully colonized and the contamination has finally stalled it out too much. Time to learn from the failure and try a different approach.
The stalled unvented jar at the end of the trial (6-16-2026).
Trial 2: Loose Lid (Status: Ongoing)
Project Goal: Test if an unmodified lid left slightly loose provides enough gas exchange for full colonization without contamination issues.
Start Date: 6-16-2026
Progress Log:
6-16-2026: New G2G transfer performed. This time, I left the unvented lid loose to allow for better gas exchange from the start. We are using a clean source to avoid the issues from the first trial.
New G2G transfers: Trial 2 with loose lid starting (6-16-2026).