Shiitake Mushroom Grow Guide
Follow these steps to successfully fruit your Shiitake (Lentinula edodes) Grow Block. This kit is suited for intermediate growers, offering a highly rewarding and savory harvest. Most DuraFungi blocks arrive fully matured and already forming mushrooms, so you can enjoy your first harvest quickly.
What You'll Need Before You Start
- Sterilised scissors or knife: For cutting the plastic.
- Mister bottle: To provide a fine, gentle mist over (not directly onto) the mushrooms.
- Tray or plate: A clean, food-safe surface to place the mushroom block on.
- 4 skewers or chopsticks: To create a simple “tent frame” for your humidity tent.
- Plastic bag: The original grow-bag (preferred) or any clean plastic bag to form the humidity tent. Don’t throw this away — you’ll use it in Step 3.
- Optional small fan: For gentle air circulation in the room (not blowing directly on the block).
Is My Block Ready? Check the Colour First
Before you cut the plastic, check the surface of your block. Shiitake blocks develop a dark brown “rind” as they mature.
🚫 Stop – Don’t Cut Yet
The block is still mostly white. This means the mycelium is still colonising and hasn’t fully matured. Leave it in the bag and allow more time until the surface turns mostly brown.
✅ Go – Time to Fruit
The block surface is fully brown (the “rind”). This shows the mycelium has finished its growth phase, recovered, and is ready to switch into the fruiting stage and make mushrooms.
Note: DuraFungi blocks are almost always shipped at this fully matured, brown-rind stage, and many already have small mushrooms forming when you receive them. The comparison above is provided in case you ever encounter an unmatured block.
🎥 Full Process: From White Block to Harvest (18 min)
This 18-minute video walks through the entire process from an unmatured white block through to harvest and troubleshooting. It’s useful background if you’re curious about the full lifecycle.
Video Credit: This guide was created by Jim at 100thMonkeyMushrooms and is hosted here for instructional use.
Step-by-Step Instructions
Most customers: Your DuraFungi block will arrive at the brown-rind “Go” stage and often already pinning or fruiting. These written steps are especially helpful for managing your first harvest and preparing for your second and third flushes.
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Unwrap & Prepare (The "Slap" Method)
Confirm your block is ready: the surface should be fully brown (the rind). This means the mycelium has matured and is ready to produce mushrooms.
Use sterilised scissors or a knife to cut the plastic. Remove the block fully from the bag, but keep the bag aside for later as your humidity tent — do not discard it.
If you can’t start straight away, you can store the block in the fridge for up to 1 week.
Slap the block once with an open palm to help trigger the fruiting response.
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Environment & Setup
Place the block on a clean tray or plate.
Ideal room temperature: 20–22°C.
Use a non-air-conditioned room such as a laundry or garage shelf.
Avoid chemicals, air fresheners, strong drafts, heaters or direct sunlight.
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Create Humidity & Pinning
Shiitake requires 85–95% relative humidity (RH).
Push 4 clean skewers or chopsticks into the tray or position them around the block to act as a simple frame.
Loosely drape the original plastic bag (or a clean plastic bag) over the skewers to form a humidity tent, without the plastic touching the caps.
Do not seal the bag tightly. Leave small gaps at the bottom, or lift the bag once or twice a day to allow fresh air in while keeping humidity high.
Pins (baby mushrooms) typically appear within 2–14 days.
Once pins (tiny baby mushrooms) appear, they normally reach harvest size in about 5–7 days, depending on temperature and humidity.
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Misting, Growth & Harvest
Mist the air around the block twice daily using your mister bottle. Aim for a fine cloud of droplets – do not soak the caps directly.
Harvest when white gills are visible underneath and the caps reach about wallet size and begin to flatten.
To harvest, gently twist-and-pull the mushrooms from the block, or cut at the base with your sterilised scissors.
General Shiitake Growth Timeline (after pinning):
- Days 1–2: Small brown pins develop and begin to swell.
- Days 3–4: Caps expand, stems thicken, and colour deepens.
- Days 5–7: Caps reach full size and start to flatten – this is usually the ideal harvest window.
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Second & Third Flushes
After harvesting, allow the block to rest for 2–3 weeks in a cool, dry place.
To restart fruiting, submerge the block in clean, cold water for 12–24 hours, then repeat the humidity and misting steps. See the refresher video below for a visual demonstration.
After Harvest: Storing Your Shiitake
Once you’ve harvested your mushrooms:
- Let the mushrooms sit for a short time at room temperature if they feel very damp.
- Place them in a paper bag or other breathable container (avoid fully sealed plastic).
- Store in the refrigerator and use within 3–7 days for best flavour and texture.
- Do not wash before storing. Instead, brush off any bits of substrate and rinse quickly just before cooking.
🎬 Quick Start & Second Flush Refresher (3 min 13 sec)
If your block arrived already brown and fruiting (the usual DuraFungi experience), this short video is a great visual companion for harvesting and preparing the block for a second flush.
Video Credit: Fat Moon Farm.
Troubleshooting & Tips
- Browning is good: The dark rind is required for fruiting.
- Over-sprayed? Use a hairdryer on cold for 2 minutes to dry the surface.
- Dry air? Place a bowl of hot water nearby and gently move air in the room with a fan (not blowing directly on the block).
- End of life: Compost the block or crumble it around plants in the garden – worms love it.
Frequently Asked Questions – Set-Up & Supplies
- How do I sterilise my scissors or knife?
- Wipe the blade with isopropyl alcohol, or carefully pass it through a clean flame for a few seconds and allow it to cool. If you don’t have isopropyl alcohol, a high-proof clear spirit (like vodka) can work in a pinch.
- What’s the difference between a spray bottle and a mister bottle?
- A mister bottle produces a fine mist, which gently increases humidity around the mushrooms. Many standard spray bottles produce larger droplets that can leave the caps too wet.
- Can I use any type of plate or tray?
- Yes. Ceramic, plastic or wooden trays/plates are all fine as long as they are clean and food-safe. If you notice moisture, residue or debris building up, wipe or change the tray every few days.
- Why do I need skewers or chopsticks?
- They act as a simple frame to keep the plastic bag from resting directly on the mushrooms, helping to maintain humidity while still allowing some air exchange. Make sure they’re clean before use.
- What’s the benefit of a small fan, and is it required?
- A small fan in the room (not pointed straight at the block) helps prevent stale air and supports healthy mushroom growth. It’s optional, but can be helpful in stuffy rooms.
- Do I need to keep the original plastic bag?
- Yes. The original grow-bag is designed to fit your block and is ideal for use as a humidity tent in Step 3. Open it carefully, remove the block, and keep the bag to drape over your skewers or chopsticks.
- Should the humidity tent be completely sealed?
- No. The goal is high humidity with some fresh air. Drape the bag loosely so there are small gaps at the bottom, or lift it once or twice a day to let fresh air in while keeping humidity high.
Frequently Asked Questions – Harvest & Storage
- How long after pins appear until I can harvest?
- Under normal home conditions, shiitake usually take around 5–7 days from the first appearance of tiny pins to reach harvest size. Warmer rooms speed things up slightly; cooler rooms slow them down.
- How do I know the perfect time to harvest?
- Harvest when the caps are about wallet-sized, the white gills are visible underneath, and the caps are just starting to flatten. If the caps become very flat or slightly upturned, they are still fine to eat but a little past peak texture.
- How long will fresh shiitake last in the fridge?
- In a paper bag or other breathable container, fresh shiitake usually keep well for up to one week, with the best flavour and texture in the first 3–4 days.
- Can I store them in a sealed plastic container?
- It’s better to avoid fully sealed plastic, as it traps moisture and can make the mushrooms slimy. If you only have plastic containers, leave the lid slightly open or poke a few small holes for airflow.
- Can I freeze shiitake mushrooms?
- Yes. For best texture, slice and lightly sauté or steam the mushrooms first, then cool and freeze. This helps them hold their texture better when reheated, compared to freezing raw.
Ready for Your Next Grow?
If you enjoyed growing (and eating!) your shiitake mushrooms, you can keep the harvests coming.
Looking for fresh blocks at the market? Check our Farmers Market page to see where DuraFungi is popping up next.