I have been storing mycelium, grown from the base of mushrooms, for months. As expected, the mycelium turned bone hard. Since mushrooms are the fruit of mycelia, I decided to revive the dried mycelium in the hope that I can grow mushrooms from them.
You can revive dried mycelium with the following steps:
- Fill the jar or ziplock bag with water.
- Leave it for 12-24 hours.
- Drain and refill the water until it is clear.
- Leave the mycelium in clear water for 12-14 hours.
- Drain the water.
- Open the mason jar for a few minutes daily.
- Check the mycelium for signs of pinning.
- Turn the jar if the mycelium at the base isn’t pinning.
The process of reviving dried mycelium varies depending on how old the mycelium is. I will discuss the steps to follow, what to expect from mycelium at different stages, and how to tell when it’s ready.

1. Fill the Jar or Ziplock Bag With Water
Add clean water to the mycelium, which is usually stored in a mason jar or ziplock bag. Ensure the dried mycelium is soaked completely.
I recommend using a jar because you can easily turn it over to get both ends wet. If you are using a ziplock bag, keep turning the mycelium to get water to cover it entirely. Ensure you zip the bag because sterility is critical when reviving mycelium.
2. Leave It for 12-24 Hours
Since the bottom of the mycelium absorbs water faster, turn the jar upside down based on its position to allow the top end to soak in the water.
For ziplock bags, ensure you position them so the dried mycelium keeps absorbing water. If necessary, place the bag in a container that holds it in place. Dried mycelium floats in the water until it is completely saturated, and you must ensure this happens.
This video is a step-by-step guide on how to revive dried mycelium:
3. Drain and Refill the Water Until It Is Clear
As the dried mycelium soaks in water, the water will start to turn yellow. Keep shaking the jar or ziplock to get as much color out of the mycelium and then drain the water. Do this as often as you need to until you are left with clear water.
You can also transfer the mycelium to a different jar or ziplock bag and add fresh water to it. Let this sit for several hours, then repeat the process until you get clear water.
The KAMOTA 12-Pack Mason Jars (available on Amazon.com) are high-quality 16 ounces (0.47 liters) glasses. They are durable, BPA-free, and food safe.
The lids seal tightly, so you need not worry about leaks or contamination. The jars are versatile, and you can use them to revive dried mycelium and also store spices, honey, and other condiments.
4. Leave the Mycelium in Clear Water for 12-14 Hours
Now that you have clear water, you should leave the mycelium to sit in it for at least 12 to 14 hours. This allows the mycelium to hydrate properly, only this time, it’s in clear water. This process is also essential because it eliminates impurities that may still be hidden in the mycelium cake.
5. Drain the Water
Drain all the water from the jar or zip lock bag containing the mycelium and transfer it to a clean jar or ziplock. Ensure you wear gloves when doing this to prevent contamination.
Seal the jar or ziplock bag, but ensure you don’t seal it too tightly and prevent airflow. I used the same jars but cleaned the lid before covering it again. However, this time, I did not seal the lid tightly, but left just enough room so I could easily rotate the lid.
Don’t close the lid tight as the mycelium releases gasses. You will notice that as the gas builds up, the lid won’t rotate so easily. Leave the mycelium as it is for a few days.
Keep checking on it to ensure you release the gas building up in the jar.
6. Open the Mason Jar for a Few Minutes Daily
The day after you have drained water from the mycelium in the jar, try rotating the lid. If it feels tight and is harder to rotate, it’s best to open the jar for a few minutes. Opening the lid will allow you to release the gas trapped inside.
You may need to repeat this action multiple times a day if there’s a lot of gas.
Mycelium doesn’t require a lot of air, but it needs a regular exchange of gas to grow. So open the jar a few times daily to release carbon dioxide because mycelium growth is stunted when there’s too much carbon dioxide.
Besides monitoring the gas buildup, you must also check the mycelium for signs of contamination and dehydration. If you don’t see any moisture at the base of the mason jar, you should rehydrate the mycelium. However, be careful when adding water, and add only a little so it doesn’t get clogged.
As you revive the mycelium, it will become an attractive host for bacteria and other contaminants. This is why you must attempt to revive it in a sterile room and be careful when handling the mycelium.
The surrounding bacteria will compromise the mycelium’s immune system, and the mycelium will start to fight back. This phenomenon can stunt its growth and recovery. Unfortunately, contaminated mycelium may not bear good-quality mushrooms.
Some may grow a few, while others will only bear fruit for one season.
Some signs of mycelium contamination include:
Discolored Patches
You will notice all kinds of discoloration on the mycelium. Green is common, but you may also see traces of pink, gray, and black.
If you see blue or yellow, it shouldn’t be a cause for concern. Blue traces signify bruising, while yellow usually signifies aging mycelium.
Strong Odors
The odor in contaminated mycelium is different from that of fresh mycelium. If you are observant, you can even smell the presence of a mold before you see it, and the odor is usually more evident after shaking the jar.
Slimy Wet Patches
Contaminated mycelium will also have slimy rings, which may appear as a gel-like substance on the surface.
Discolored Powdery Layer Covering the Mycelium
When contaminated mycelium starts losing moisture, it will develop a discolored powdery layer at the top and sides.
If the mycelium is contaminated, remove it from other batches of dried mycelium you are trying to revive or the contamination might spread to the entire mycelium culture. It’s best to also sterilize your room and monitor the other mycelium for signs of contamination.
7. Check the Mycelium for Signs of Pinning
Over time, if the mycelium isn’t contaminated and it’s moist enough, it will get dense and start pinning, where mushrooms start growing out of air holes within the mycelium. When you start noticing pins in the mycelium, it indicates that you have successfully revived the dried mycelium.
8. Turn the Jar if the Mycelium at the Base Isn’t Pinning
As the mycelium colonizes and grows, you should see a change in the entire structure. However, sometimes, the growth halts, and it’s important to monitor how the dried mycelium responds to your efforts to revive it.
If you discover that the growth stops before the entire mycelium is colonized, you should consider turning the jar upside down. In your attempt to revive the mycelium, the water may remain at the base of the jar. However, excess moisture interferes with mycelium growth and should be rectified.
When you turn the jar, the excess moisture moves to the colonized side. This gives the mycelium at the base of the jar a chance to grow some pins. Turning the jar over also allows for the movement of gasses while speeding up the pinning process.
If the mycelium that’s developing well is at the side, you can shake the jar lightly to improve the movement of moisture and gasses. If necessary, place the jar on its side so you can better monitor the mycelium to confirm if the changes are helping.
When it is fully colonized, you can transfer the mycelium to a fruiting chamber so the mushrooms have sufficient space to grow.
Conclusion
Mycelium enters dormancy when it is dried and can be activated through rehydration.
However, sometimes, dried mycelium fails to show signs of colonization, and the failure can be attributed to various reasons, including:
- Insufficient moisture
- Excess water
- The environment not being sterile
- High carbon-dioxide buildup in the jar
To successfully revive dried mycelium, you must follow the steps correctly and monitor the mycelium’s response.