Commercial mushroom farmers and hobbyists alike use bags as part of their mushroom-growing operation; they are, as the name implies, a bag designed to grow mushrooms in.
Depending on the substrate or growing medium you use, you can utilise bags to cultivate a wide range of mushrooms. Mushroom grow bags come in a variety of sizes and thicknesses. There are even special mushroom bag brands that we like over others.
In this article, we will go through the various types of bags that are available, as well as how to grow mushrooms in bags.
Mushroom fruiting bags have become an extremely popular way for home growers to cultivate gourmet mushrooms. These pre-inoculated blocks contain mushroom spawn embedded in a substrate like sawdust, straw, or wood chips. With some basic care and optimal conditions, the mycelium will colonize the substrate and produce flushes of mushrooms. While fruiting bags make mushroom growing easy, there are still some key things you need to know to get the best results. In this complete guide, we’ll cover everything you need to successfully care for mushroom fruiting bags from start to harvest.
Choosing the Right Location
Choosing the optimal location is the first step in caring for your mushroom fruiting bags. Most gourmet mushroom varieties perform best at temperatures between 55-75°F. King oyster and pearl oyster mushrooms can tolerate slightly warmer conditions while shiitake prefer it a bit cooler. Avoid areas that get over 80°F or under 50°F. High humidity is also essential, between 80-100%. Find an indoor spot away from direct airflow but with good air circulation. A garage, basement, or insulated shed are good options. You can also grow outside in a shady spot during cooler months. Just bring the bags indoors if temperatures drop below 50°F at night.
Maintaining Proper Moisture Levels
Keeping your mushroom fruiting bags properly hydrated is crucial. The mycelium and developing mushrooms need constant moisture. Check the bags daily by lifting them and feeling the weight Adequately hydrated bags should feel heavy. If light, it’s time to mist them or soak the blocks Bags may need misting 1-3 times per day depending on humidity levels. Spray them with clean water in a fine mist to avoid over-saturating. If the substrate dries out completely, you’ll need to soak the bags in cool water for 4-8 hours to rehydrate thoroughly. Don’t let them sit in water logged. Proper moisture encourages mushroom growth and prevents contamination.
Providing Good Air Exchange
Mushrooms require fresh air to grow well so adequate air exchange is essential. Avoid tightly enclosing the fruiting bags. Leave space between them if cultivating multiple bags together. You can elevate the bags on wire racks or wooden blocks to allow airflow underneath. Gentle breezes and small fans also help circulate air but avoid directing fans right at the bags. Rotate the bags daily so all sides get exposure. Opening a window briefly to refresh the growing area can provide a boost of fresh air too. Just don’t let temperatures drop too low. Remember, gourmet mushrooms prefer still air but need occasional exchanges of oxygen.
Introducing Light to Initiate Fruiting
Exposing your mushroom bags to light is what triggers the formation of mushrooms. Keep the bags in complete darkness during the mycelium colonization period which takes 2-4 weeks. Once fully colonized, move the bags to a lightly lit area to initiate fruiting. Bright, indirect sunlight or fluorescent light about 12 hours daily is ideal. You should see primordia (baby mushrooms) develop within a week. If growing indoors, set up a simple grow light on a timer to control exposure. Avoid direct hot sunlight which can dry out the bags. Gentle natural light is best for mushroom development.
Harvesting Mushrooms at Peak Maturity
Now for the rewarding part—harvesting your homegrown mushrooms! Check your fruiting bags often as mushrooms mature rapidly, sometimes overnight. Harvest each mushroom by twisting gently until removed from the substrate. Use a knife to cut away any stubborn stems. Pick mushrooms before the caps flatten out for best flavor and texture. They’re optimally mature when the caps just start to curl under. You can harvest mushrooms of any size based on your preference. Try to handle the mushrooms gently to avoid bruising. After the first flush, repeat steps to maintain ideal conditions for additional flushes. Rehydrate and rest bags between flushes.
Caring for mushroom fruiting bags requires attention but very little effort. Following this guide will help you create the right environment for your bags and maximize your mushroom yields. With a bit of practice, you’ll discover how to produce flush after flush of delicious, nutritious gourmet mushrooms!
How to Seal and Inject the Mushroom Grow Bag
After adding the spawn to the grow bag, you should close the top and put it on a shelf so the mycelium can start to colonize. There are a couple easy ways to do this:
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Use small pieces of wire to tightly twist the top of the bag closed Steel wire found at any hardware store works well
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Zip ties are quick and easy to seal the bag, but more costly than wire.
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Impulse sealers are the best option for high volume grows, sealing bags quickly and efficiently.
When ready to inject, sterilize the injection point and needle. Insert the sterile needle through the injection port. Use 2.5-5 ccs of spore or liquid culture per bag. Higher inoculation rates speed up colonization and reduce contamination risks.
After inoculation, avoid shaking spawn bags to prevent disrupting fungal spore germination. Let the bag sit undisturbed while the mycelium colonizes over the next 4-8 weeks.
Uses for Mushroom Grow Bags
There are many great ways to use mushroom grow bags:
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As spawn bags to expand grain spawn, easily break up for faster colonization.
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For creating supplemented sawdust fruiting blocks. The bag’s filter patch provides needed air exchange.
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Alternative to poly tubing for making mini mushroom-growing straw logs.
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Small fruiting chambers since the bag creates a humid dome for mushrooms to grow in.
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Reishi mushrooms will grow long antlers inside the high CO2 environment of a sealed bag.
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Cooking casing layers by filling used bags with substrate and hot water.
With proper sterilization, used bags can often be reused for spawn or blocks again. But replace old bags after several uses to lower contamination risks.
Choosing the Right Mushroom Grow Bags
When purchasing spawn bags, pay attention to the micron rating of the filter patch. 0.2-0.5 microns is best for spawn and fruiting blocks, protecting against contaminants.
Larger bags around 8″ x 5″ x 18″ comfortably hold 5 lbs of substrate, fitting 6 bags in a standard pressure canner. Thicker 4 mil bags are more durable but pricier than 2.2 mil bags.
Start with new bags for sterile cultivation. After multiple uses, old bags become less reliable even with sterilization. New filter patches and substrate eliminate variables.
Caring for Spent Mushroom Bags
Once your fruiting bags stop producing mushrooms, you can:
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Compost the nutritious substrate in your garden.
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Reuse or recycle the bags if possible after thorough cleaning and sterilization.
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Safely dispose of any contaminated bags sealed tightly to contain spores.
Don’t toss unused mushroom bags in the trash. Look for sustainable ways to repurpose or compost the materials.
Tips for Success with Mushroom Fruiting Bags
Follow these tips for the best experience with mushroom grow bags:
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Start with easy oyster mushroom varieties if new to growing.
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Track temperature, humidity, and other conditions in a journal to improve results over time.
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Give fresh harvested mushrooms as gifts to share the joy and satisfaction of DIY cultivation.
With some basic care and optimal conditions, mushroom fruiting bags provide a fun, rewarding way to grow your own gourmet mushrooms right at home.
Different types of growing bags
There are many brands and types, but all good grow bags share certain features. Below we list a few popular features of mushroom growing bags:
- Polypropylene: Grow bags are made of high-temperature-resistant polypropylene plastic. The material is long-lasting, flexible, and transparent enough to make growth monitoring simple. It’s also reasonably inexpensive.
- Gusseted: When not in use, a gusseted bag includes folds in the sides that allow a large, roomy bag to fold flat. The mushrooms don’t care if the grow bags are gusseted or not, but the feature helps farmers stay organised.
- Filter patch: A filter patch is a small section of the bag that permits air to enter through a fine mesh. Because the mesh is so small, airborne germs and spores of undesired fungus species (weeds) cannot pass through. A mushroom grow setup, unlike a vegetable garden, cannot be weeded; weeds must be kept out from the start or the batch must be discarded due to contamination. Mushroom grow bags require filter patches because, while weeds must be kept out, the mycelium has to still be able to breathe.
Autoclavable: The term “autoclavable” simply signifies that the bag can be used safely in an autoclave. Temperature resistance is critical because both the substrate and the inside of the bag must be sanitised prior to inoculation. Sticking the bag and its contents in an autoclave is a convenient sterilising option – most plastic bags would melt in such conditions.
Pasteurising your substrate in the growing bag
Begin by soaking your straw pellets in cold water. You can use hot or boiling water to further pasteurise the pellets if desired, however, this is not required.
Allow the pellets to sit for 30 minutes after adding water to ensure they are properly hydrated, let the mixture cool to room temperature before proceeding if you use hot water.
Fill the growing bag with the substrate mix Add oyster mushroom spawn to your hydrated pellets, mix everything together and add it into your plastic grow bag.
Leave the top third of our straw pellet bags vacant to allow for air exchange through the filter when utilised using straw pellets. However, if you use chopped straw, you can fill the bag all the way to the top. The bigger straw particles allow for much-improved air exchange.
Mushroom fruiting blocks 3: top fruiting for great pinset
FAQ
How to take care of a mushroom grow bag?
Allow your bag to colonize undisturbed and out of direct sunlight. Temperature for incubation shouldn’t exceed 75 degrees F or dip below 55 degrees F. Keeping your bag at the higher end of the temperature range will encourage faster colonization.
Do mushroom bags need to breathe?
Yes, mushroom grow bags do need to breathe. Like humans, fungi consume oxygen and release CO2 and need fresh air to survive. Mushroom mycelium tolerates higher levels of CO2 during colonization, so the breathable filter patches or micro-perforations in mushroom growing bags allow sufficient air exchange.
How often should I mist my mushroom grow bag?
You should mist your grow kit 3 times daily with about 3-5 sprays each time. However, everyone’s environment is different and the amount of misting may vary. If your mushrooms look a little dry, consider increasing the amount of misting.
When to cut holes in mushroom bag?
The ideal time to open your mushroom grow bag is when the mycelium has fully colonized the substrate, which is typically evident when the bag appears white and fluffy with mycelium.
How to grow mushrooms in a fruiting bag?
Use a sterilized knife or scissors to cut open the bag. Dip the blade of your knife or scissors into rubbing alcohol or a bleach solution, and then let it dry completely before using it. 3. Cut open the fruiting bag Carefully cut open the top of the fruiting bag, making sure not to touch the substrate or any part of the mushroom growing inside.
What are mushroom grow bags used for?
Mushroom grow bags are an essential tool for cultivation, both for the professional cultivator and the enthusiastic hobbyist. They can be used as spawn bags- in which the bags are used for sterilizing grain and propagating mushroom cultures- or, they can be used to create supplemented sawdust fruiting blocks for growing gourmet mushrooms.
When should I open mushroom fruiting bags?
The timing for opening mushroom fruiting bags depends on several factors, including the growth stage of the mushrooms. With the right timing, you’ll be able to maximize your harvest and have a bountiful crop of mushrooms.
Can a mushroom bag be kept closed during fruiting?
While it is possible to keep the mushroom bag closed during fruiting, the bag must be only partially filled to provide enough space for the mushrooms to grow. In this case, the bag acts as a miniature fruiting room, allowing for better control of humidity and other factors.
How can you reuse a mushroom grow bag?
You can reuse the bag to make mini straw logs instead of using poly tubing. Just fill the cleaned bag with pasteurized straw and grain spawn and you normally would when growing mushrooms on straw.
When do oyster mushroom fruiting bags open?
Once the substrate is fully colonized, the fruiting bags should be opened and placed in a fruiting chamber with high humidity and moderate to low light. The mushrooms will usually begin to fruit within a few days of being exposed to these conditions. 2. Oyster mushroom fruiting bags should be ready to open after 10–14 days