... and What You Can Do About It 🤷♀️
Many mushroom growers face a frustrating issue: after incubation, only part of the blocks begin pinning, while the rest “catch up” a few days later.
This slows down the harvest, disrupts turnover, and makes sales planning harder.
Let’s break down the reasons for this and what you can do to synchronize pinning across your blocks.
Even when all blocks are prepared on the same day, uneven substrate preparation can lead to uneven colonization and pinning.
Here’s why:
▶️If you're using a mix of ingredients (regardless of pasteurization method), improper mixing can lead to nutritional inconsistencies between blocks. Also, water might not distribute evenly. Mechanically mixed substrates (e.g. in tunnel pasteurization) tend to be the most uniform.
▶️When using lime water soak, the lower layers of material usually get more saturated.
Mixing or pressing the substrate afterward (e.g. with a centrifuge) doesn't always fix the issue. Loosened fibers may actually help — enzymes can reach the cellulose more easily and speed up colonization. But if they’re still too wet, that excess moisture can hold things back.
▶️In hot water treatment, some material near the tank walls or water surface may be under-pasteurized due to lower temperature.
▶️In steam chambers, certain areas may get less heat.
💡Tip: If your treatment involves high heat, insulate your tanks or chambers from the outside.
What to do: Fix what you can — and accept that no process is perfect.
📌Read all about substrates
If you don’t weigh your spawn and blocks carefully, some will get more spawn than others. Unsurprisingly, those will pin earlier.
What to do:
✅Stick to a spawn rate that suits your substrate. For example: 400 (or 600g) (14 or 21 oz) of spawn per 10kg (22 lb) of substrate.
✅Mix the substrate thoroughly with spawn.
Important! If you're using cotton waste, this may not apply. 📌Details here.
Even if all blocks were prepared together, they may develop differently.
Why:
▶️Different zones in the incubation room may vary in temperature and humidity.
▶️Densely packed substrate slows down colonization.
▶️Some blocks may be too wet or too dry.
What to do:
✅Ensure gentle air movement to circulate and equalize temperature and humidity.
✅Group blocks not only by production date but by colonization level. Before fruiting, make sure they all look evenly mature. If you have a separate incubation space, leave the slow ones to catch up.
Modern oyster strains (at least in Europe and the post-Soviet region) do not respond to shock fruiting. Instead, all environmental parameters must shift gradually — but simultaneously.
A common mistake is to change just one parameter (e.g. lowering temperature) and delay the others (ventilation, humidity). As a result, each block “decides” to start fruiting at its own pace.
One powerful and often overlooked trigger: turning on the lights.
What to do:
✅Change all fruiting conditions at once.
📌See the full algorithm here.
✅If your incubation room has blocks at different stages, you can’t change all the conditions at once just for the mature ones — so you have to move them to the fruiting room, where it’s harder to keep things in sync.
💡One workaround: use a small space to pre-trigger pinning for one batch. Transfer them to the fruiting room only when hyphal knots appear. Downside: more manual work.
Even with a smooth transition, some blocks may end up in “bad” spots — near the wall, under the ceiling, next to the exhaust.
What to do: Check your airflow! Ideally, it should travel along the rows — from the inlet to the exhaust. Use an anemometer to make sure airflow from ducts is even.
Even within one strain, block behavior can vary due to:
▶️Heat stress, oxygen deficiency, or moisture swings during incubation.
▶️Some strains naturally tend to pin slowly and in waves.
What to do: Keep a grow journal. Track incubation conditions and fruiting results. Patterns will emerge — and help you prevent future issues.
Synchronized pinning is the result of well-planned conditions and consistent airflow. While complete uniformity is nearly impossible, you can reduce variation by:
✅Selecting only mature, colonized blocks,
✅Using a method that promotes synchronized pinning,
✅Providing consistent conditions throughout the fruiting room.
If you're growing commercially, synchronization means not just convenience — it means profit. Investing in good ventilation and control systems is well worth it.
Emoji guide: 📌 link | ✅ advice | ▶️ fact |💡important
