A Simple Guide in Growing Shiitake Mushrooms in Bags

Grow your own umami-flavored mushrooms with this guide in growing Shiitake mushrooms in bags.

If you already have some experience in fungiculture, it’s time you try to grow some Shiitake mushrooms. Compared to oyster mushrooms, shiitake is a bit more challenging to grow. Its mycelium needs a longer incubation phase. It is also not as fast-growing as an oyster’s. Growing Shiitake mushrooms in bags require extra but worth-it work.

Why Grow Shiitake Mushrooms?

When we do something, we need motivation, especially if it is difficult. We need to look forward to something. That is also the case in growing Shiitake mushrooms in bags. Here are three reasons to motivate you to grow Shiitake mushrooms.

Expensive To Buy

One of the reasons why you can’t have Shiitake mushrooms all the time is because they are expensive. The demand for this mushroom is higher than the supply. Mushroom foraging won’t give you consistent stocks of Shiitake. Growing them yourself will stop you from buying them. Plus, if you have any extra mushrooms, you can even sell them.

Amazing Health Benefits

When it comes to health benefits, Shiitake has a lot on its list. This fungus is rich in fiber and B vitamins. It is also low in calories and sodium. This mushroom is good for your heart and immune system. For more info on Shiitake’s health benefits, check out the Health Benefits of Eating Mushrooms.

Delicious Umami Flavor

One of the reasons why Shiitake’s demand is high is because of its unusual taste. Its earthy flavor is called “umami” which is used in many traditional Japanese dishes. Plus, you can put these medicinal mushrooms in any dish you like.

Growing Shiitake Mushrooms In Bags

Now that we have that motivation to keep us going. It’s time we learn the process. There are many ways to grow Shiitake. But in this case, we are growing Shiitake mushrooms in bags. And here is what you should do.

Growing Shiitake Mushrooms In Bags: Preparation

In this section, you will figure out how to get some Shiitake spawns. We will also learn how to prepare the substrate. This includes what substrate to use.

Step 1: Get a Shiitake Spawn

Just like any mushroom spawn, you can also buy Shiitake Spawn online. There are two known kinds of Shiitake spawn: Grain Spawn and Sawdust Spawn.

Sawdust spawn is a very common Shiitake spawn. It is also one of the cheapest. However, they are best used when growing shiitake on logs.

Known as a lower generation and having a higher nutrient profile, grain spawn is a good option to use. You can use this if you have plans to further expand the substrate. Or you want to add nutrients to your substrate. This is great to use if you are growing Shiitake mushrooms in bags. So this is what you should buy.

Getting your spawn through mushroom spores is also okay. But if this is your first time growing Shiitake mushrooms, this is not recommended. Once you get a hang of growing through a spawn, you can go for getting mushroom spore prints.

Step 2: What Substrate To Use

Unlike Oyster mushrooms that can grow almost anywhere, Shiitake is very picky. It needs a wood-based substrate to grow. They feed on the nutrients that are found in wood.

Usually, they are grown on logs. But since we are growing Shiitake mushrooms in bags, we’ll need sawdusts. When it comes to the kind of sawdusts, oaks are the best. Alternatives include maple, beech, and ironwood. It is also good to add supplements like oat, bran flour, and grain.

Step 3: Mixing the Substrate and Putting them in the Bags

Once you got the substrate and the supplements, you can now put them in bags. If you plan to buy grow bags, pick the ones with filter patches. But if you are going to DIY it, make sure to add small holes to the bag. This will give the bags minimal airflow.

Using a sterilized pail or laundry tub, mix the substrate and supplements with water. Make sure the substrate is not too wet or too dry. You can check this by squeezing the sawdust. If small droplets of water came out of the sawdust, then you are good to go.

Afterward, put the mixture in the bags. Use a pitcher when transferring the mixture into the bag. Make sure to keep the sealing area of the bag clean and not wrinkled. Then fold the bag. You can seal it using a tape or rubber band if it doesn’t have a sealer.

Step 4: Steaming and Cooling Process

The next step is to steam the bags. There are two ways you can do the steaming process: autoclaving and atmospheric steaming method. In autoclaving, you’ll need a pressure cooker. Bring the substrate’s temperature up to 250℉. Maintain it at that temperature for two hours.

If you are doing atmospheric steaming, you’ll need a regular steamer. You need to keep the temperature at 208℉ for 16 hours. This is the least expensive method and very effective.

After the steaming process, you’ll need to cool the bags before planting the spawn. Cool them for at least 24 hours. At this stage, the bags are sucking air in. That is why it is important to place them in a sterilized environment to avoid contamination. The best place to cool these bags is in a positive pressure lab.

Growing Shiitake Mushrooms In Bags: Planting the Mushroom Spawn

In this section, we’ll go over how to plant the spawn and the incubation process.

Step 5: Inoculating the Spawn

To do this, first, open the cool bag in front of a laminar flow hood. This is done to avoid contamination. Then, drop a small amount of the spawn into the bag. Next, fully seal the bag so that air exchange can only happen through the filters. Lastly, shake the bag to evenly spread the spawn in the substrate.

Step 6: Incubating the Spawn and Browning

Once the spawn and the substrate are mixed and sealed, it’s time to incubate the bag. You can do this by using a mushroom grow chamber and humidifier. The ideal incubation temperature is anywhere around 55℉-75℉.

Also, if you have more than one bag, make sure to place a distance between each bag. This is done so that the bags can “popcorn” with ease. This is especially critical during the second week of incubation.

Another thing to take note of is the sensitivity of shiitake with sudden temperature swings. A drastic drop in temperature can ruin the growth of the mushrooms. So be sure to maintain its current temperature.

Once that is settled, you can just sit back and watch the mycelium grow. Make sure that it stays healthy. Also, watch out for contamination.

During the incubation process, the mycelium will spread on the substrate. Then, the “popcorning” will begin. This will create ridges and valleys on the substrate. The last phase is the browning of the mycelium. Once this happens, pins will begin to sprout. Usually, it takes up to 8 weeks before the substrate browns.

Growing Shiitake Mushrooms In Bags: Fruiting and Harvesting

In this section, we are going to talk about fruiting initiation techniques. This will help in giving growth cues to the mycelium. Then, we’ll also learn the best time to harvest the shiitake mushrooms.

Step 7: Cold Shocking

To initiate pinning, it is important to cold shocking the bag. You can do this by reducing the temperature to 41℉ for 12-24 hours. One of the ways you can do this is by placing the bag in a refrigerator. You can also just place it in a cold and clean area in your house.

Step 8: Removing the Block from the Bag

Once you are through with cold shocking the bag, it is time to remove the block from the bag. Now, place your spawn block in a humid area. If you used a mushroom grow chamber, just open the lid. Your spawn block will need a lot of fresh air at this stage.

Within a week, the first flush of Shiitake will appear on the block. Unlike the oyster mushroom, Shiitake can appear at all sides of the block. It is also important to spray some water on the block. You should do this several times a day to prevent the block from drying out.

A spawn block can produce at least three flushes of mushrooms before the mycelium weakens. In some cases, it can produce up to five flushes. But be careful. Once the mycelium weakens, there is a high risk of mold contamination.

Step 9: Harvesting

When it comes to when to harvest the Shiitake mushrooms, there is no size standard. Most of the time, it’s your choice when you harvest them. But it is good to note that the smaller they are, the more tender they are. If you want your Shiitakes to grow larger, that’s fine too. But take note that the larger they are, the shorter their lifespan. Make sure too that they are dry on the outside.

However, you should make sure to harvest them before they pass their prime. The hotter the temperature, the faster they grow. So much mushroom growth can happen in just 24 hours. The best indication, if they are in their prime, is before the mushroom cap flattens or flipped up.

When it comes to how to harvest the Shiitakes, the best way is to use a knife or large scissors. Twisting them can damage the mycelium which will prevent it from sprouting more flushes. Cut the mushroom at the base of their stem. Then, place the mushroom in a clean container. Keep minimal contact with the fungus as much as you can.

Growing Shiitake Mushrooms In Bags: Growing Again

After taking your first harvest, don’t throw the fruiting block. As mentioned, a Shiitake fruiting block can sprout more flushes. There are times that the second or third flush gives a better harvest than the first flush.

However, the fruiting block needs to rest. They need to be re-energized by drying them out. Usually, the drying process takes at least a week. Make sure to turn the block on different sides to prevent molding. After that, soak the fruiting block in water and leave it for 24 hours. Then lastly, repeat Steps 6-9.

If you have exhausted your fruiting block, you can make another fruiting block. As for the spawn, it will depend on you if you want to buy it again. But since you already have the experience, why not get the spore prints of your freshly harvested Shiitakes. Find out how to successfully get the spore prints here.

Try Growing Shiitake Mushrooms In Bags

And that is how you grow Shiitakes in bags. It’s not as complicated as you thought, right? It’s okay if you didn’t get the results you want at the first attempt. Just keep practicing in growing your Shiitake mushrooms in bags. Eventually, you’ll get it right and get a fresh supply of Shiitakes.