Grow Mushrooms With Rice (Revised and Improved!)

Welcome to our award-winning, newly revised mushroom growing guide, which has been viewed by over 36,000 makers at Instructables. Our team at Mycelerator Systems has dedicated the past year to designing and improving our mushroom growing systems, conducting hundreds of test grows to improve our products. 

We're excited to share this new growing kit as widely as possible, building a royal road for all interested Do-It-Yourselfers to become mushroom growing enthusiasts! 

In this instructable, we present an easy way to grow mushrooms directly from cooked organic rice bags that you get from your grocery store! You can grow a variety of mushrooms using the approach described here. We’ll take you through the steps that will transform your brown rice into a mushroom harvest!

Why Grow Mushrooms?

Mushrooms are a hidden part of the world to most people. Unlike plants, they've only been recently farmed, and their behavior is very different from plants. Plants grow with sunlight and soil, where most mushrooms grow in the earth by building mycelial networks, processing organic material, only surfacing to "fruit" mushrooms to reproduce.

Aside from the fact that they are amazing to learn about, there is solid evidence that, aside from mushroom recipes, mushrooms protect you from disease in many ways, and have incredible therapeutic value. Here's a quote from Paul Stamets, the statesman of mycologists:

"Mushrooms have the potential to revolutionize medicine, agriculture, environmental protection, and many other fields."

Why Use our System?

For this revised tutorial, we owe everything to the folks in the Uncle Ben's community on Reddit. That's where the approach of using prepared brown rice bags from the grocery store originated, and there are good people that can help you out if you drop in.

This version of their techniques helps you avoid a lot of work that you'd normally have to do to grow mushrooms. You'll spend less than 10 minutes per week with your mushrooms until they're ready for harvest in (typically) four to six weeks.

We've spent a lot of time testing so that you get the most efficient, easiest process to growing mushrooms at home. We're excited to have you starting growing mushrooms now!

To get started you'll need the following supplies (available on our website or Amazon for under $30):

1. Mushroom liquid culture. This is like "seeds" for mushrooms. Liquid culture is available from many vendors, such as Southwest Mushrooms, North Spore and MillyWyco. You'll only need around 3 mL of liquid culture for each grow, so if you get a syringe with more than that, put the syringe in the refrigerator after you use it here, and you can use it for your next grow. 
2. One bag of Uncle Ben's Brown Rice, available at your local grocery store, or Amazon.
3. Synthetic filter stickers. You can get these at Amazon or you can use 3M Micropore Tape available at pharmacies.
4. Alcohol wipes
5. Hot punch and a candle or lighter (you'll need to do some assembly - see below)
6. A bag of Coconut Coir. Available at local gardening shops and Amazon.
7. You'll need a box or a tray with a top for the fruiting phase. Something the size of a shoebox should be fine, and it should be made with food grade materials. We include this EarlyGrow Tray for fruiting in our kit. 
8. Spray bottle

Here's an Amazon materials list for most of what you need. This is just a suggested list, as you only need one of each individual item, but Amazon will want to sell you more. As mentioned earlier, you can also get a kit already made for this instructable from either Amazon or our website.

Make your own Hot Punch

You'll need a Hot Punch. This tool will make a sterilized hole in the rice bag so that the rice can be infused with mushroom liquid culture. It comes premade in the kits above, but it shouldn't take you more than a minute to make it yourself!

Make Your Hot Punch

Get the following: 

1 wood dowel (around ½ “ by 2“)

1 upholstery tack

Hot Punch Assembly: Push the upholstery tack into one end of the dowel. Voila! You've built a hot punch!

Ready? Let's get started!

Supplies for Step 1

Make sure that you have your Mushroom liquid culture on hand.

If you have the kit version, use the gift certificate to select and order the variety you want to grow. The liquid culture is free! 

1. Ben’s Original Whole Grain Brown Rice Bag 
2. Mushroom liquid culture syringe  
3. Once you receive your liquid culture, you can continue this step.
4. Alcohol wipes 
5. Hot punch 
6. Candle or Lighter
7. Microfilter

Prepare a clean area to work in. We recommend the kitchen (cleaned to food preparation standards) without open windows or operating fans. Contamination is introduced easily when airborne particles get into the bag. 

Gently squeeze and shake the brown rice bag, so you’ll be able to see changes in this step. 

Infusion 

1. Push all of the grains from the top of the bag to the bottom, below the “WHOLE GRAIN BROWN” banner. 

2. Place the rice bag in front of you. Use an alcohol wipe to wipe off the middle of the “WHOLE GRAIN BROWN'' text. Leave the alcohol wipe on top of the wiped area 

3. Heat your hot punch by holding it in the flame for about 20 seconds.

4. Remove the alcohol wipe. Apply the hot punch to the area in the middle of the area you just wiped. Put the alcohol wipe back over the hole to cover it. 

5. Shake the syringe, then remove the stopper and place the tip into the hole you made in the middle of the rice bag. Inject 2-3mL of the live culture into the rice. Place the alcohol wipe back over the hole. 

6. Remove one synthetic filter, place it over the hole and wipe it with the alcohol wipe. 

Colonization

Write the date on the bag and place it in a warm, dark area, like a kitchen cabinet. Do not place it near a heat source. 

Ideal temperature for colonization is 75℉, but should work within a range of 65-80℉. 

After a few days, take a look at your bag. You might see some white forming in the grains of rice in the transparent window on the bottom of the bag. Squeeze the bag gently -the rice should be at bit firmer. What is really important here is to not rush things. Full colonization typically takes two to three weeks, but the actual time to complete colonization is affected by temperature, humidity and mushroom variety.

During colonization, the major hazard to your mushrooms is doing too much. Mushrooms aren't plants: don't water them, fertilize them, or put them in the sunlight. Be patient

If there is a sour odor, the bag is watery and squishy, or green or black shows in the window after two weeks, you’ll need to try again. 

When the bag’s window is solid white, and the rice in the bag feels firm when squeezed, continue the instructions in Step 2

If you got the kit from our site or Amazon, the substrate has been pre hydrated and sterilized for you, so you can skip Step 1.5 and go straight to Step 2. 

For people without the kit, you'll need:

Supplies

• Bag of substrate mix 
• 7 cup (or larger) bowl w/ lid
• Water (non-chlorinated water is preferred)
• Implement for stirring (a fork works best)
• Measuring cup

Instructions 

1. Bring water to a boil.
2. Empty substrate bag into the container.
3. Add  1 ¼ cups (10 oz.) of boiling water.
4. Secure the lid and let sit for 5-10 minutes while the coir rehydrates.
5. Mix thoroughly.
6. Let it cool completely with the lid on (approximately 2 to 4 hours) 

Combine with the colonized rice within 24 hours.

Supplies Needed for Step 3

Colonized brown rice bag from Step 1

Sterilized/Hydrated substrate (see Step 2 if you didn't get the kit) 

Fruiting Tray with Top

You’ll need a fork and a big mixing bowl from your kitchen for this step. Use a bowl that can hold seven cups or more for best results. 

Examine your Colonized Rice 

Open the top of the brown rice bag with scissors. The rice and mycelium should be a nearly solid block of white. If you break a piece off, mycelium should show white veins throughout the rice. 

Mix Rice and Substrate 

1. Start by emptying the substrate into the mixing bowl from your kitchen. 
2. Place the block of mycelium into the bowl. Using your fork (or your hands if you like), gently break apart the colonized rice from the bag into small pieces and place them in the mixing bowl. Dispose of clumps that are slimy or have a sour odor. 
3. Mix the colonized rice and substrate together thoroughly. 
4. Remove the top of the Fruiting Tray. Put the mixture into the tray, distributing it so that the mixture is spread evenly on it. 
5. Place the top back onto the Fruiting Tray. If your tray has vents, adjust them so that they're closed. 

Place the tray in a warm dark area, like a kitchen cabinet. Do not place it near a heat source. Ideal temperature for colonization is 75℉, but should work within a range of 65-80℉. 

During Colonization 

Leave the Fruiting Tray in a warm dark area with some airflow. Continue checking on the progress of the colonization over the next week or two. After a few days, take a look at the tray. The mixture in the tray should show areas of white mycelium growing. 

Be patient. Full colonization typically takes one to three weeks (or more, depending on variety). Just like with Step 1, mushrooms progress on their own schedule. We've found that sometimes a grow may take a few more weeks, and then deliver a spectacular harvest. 

When the surface of the mixture in the tray is solid white, continue the instructions in Step 3.

You may think you're ready for the next step, but...

Be patient. Full colonization typically takes one to three weeks (or more, depending on variety). Just like with Step 1, mushrooms progress on their own schedule. We've found that sometimes a grow may take a few more weeks, and then deliver a spectacular harvest. 

When the surface of the mixture in the tray is solid white, continue the instructions in Step 3.

Supplies

Fruiting Tray with mixed substrate and colonized rice 

Spray bottle 

You’ll complete your mushroom harvest with this step. 

Preparing for Pinning 

1. Remove the top of the Fruiting Tray. 

2. Spray a mist of water over the mycelium. You want a mist of water to gently rain down over the tray. Avoid spraying directly into the tray where the mycelium is. Put the top of the tray back. 

3. Open the vent on the tray top all the way. 

Over the next week or two observe the Fruiting Tray daily. 

Remove the top of the tray and spray a mist of water over the tray once a day (or every other day, depending on the mushroom that you’re growing). Examine the surface for the formation of pins. These are small bumps or clusters of growth, sometimes resembling pinheads. When you see this, you’re ready to fruit. 

If a week has passed and there are no signs of pinning, you can try putting the tray on the top shelf of the refrigerator overnight. Remove it during the day. Make sure that the tray has some indirect light, and continue to mist. Repeat this over three nights, then return it to the warm location with indirect light that you have selected. 

If you observe a rapid growth on the surface that is white and cloud-like, turning green or gray, you probably need to start again. Somehow, your grow got contaminated. Don’t worry, it happens to everyone☹️. If you have a Refill Pack you can try again. 

Fruiting and Harvesting

Once you have pinning, it is time to fruit the mushrooms. This normally is complete within a week. Keep the vents open on the top of the Fruiting Tray. Mist the mushrooms every day. When the rate of growth slows down, the caps will flatten out or curl upward. Twist and pull each cluster of mushrooms from their base to harvest.

Congratulations for finishing this instructable! Live long and prosper.

If you have any questions or suggestions about this instructable, you can add suggestions on this page, or email us at instructable-questions@mycelerator.com.

Let’s Grow!

1. Growing Gourmet & Medicinal Mushrooms, by Paul Stamets. Available at https://fungi.com/products/growing-gourmet-and-medicinal-mushrooms.
2. Growing Mushrooms: PF Tek, by Nak. Instructable here: https://www.instructables.com/Growing-Mushrooms:-PF-Tek/
3. Mushroom Terminology. North Spore. Article here: https://northspore.com/pages/mushrooms101
4. AI-based Mushroom shown above courtesy this instructable: Making Art in 60 Seconds With AI: a Short Tutorial for DiffusionBee

“…but I also can’t prove that mushrooms could not be intergalactic spaceships spying on us.” ~ Daniel Dennett

1. What if my colonization didn’t happen/looks weird?

Colonization never started. This usually means that the live culture you used had a problem with it. One common problem is that live culture has a definite shelf life (you can extend it to at least a few months by putting it in a refrigerator). If this occurs, contact your liquid culture vendor and they should send you a replacement syringe. Stuff happens.

Colonization started, but the rice is contaminated. If you have green or black areas in your bowl, it has been contaminated by bacteria or other fungi. If their areas are small, you can carefully remove them from the bowl and continue the fruiting process. There is no guarantee this will work, however. It may be best to throw out the bowl and start again, with additional attention paid to use the alcohol wipe to sanitize anything that is used around the hole you make with the hot stamp.

Colonization completed, but there are small growths on top of the mycelium. This is good news! Your bowl is aggressively moving toward fruiting. Continue from Step 4: Move Your Bowl Of Mycelium To The Grow Chamber.