liquid culture how to guide

Your Guide To Using Liquid Cultures

How To: Use Liquid Cultures To Grow Mushrooms

Three Ways To Use A Liuid Culture

Using this guide will provide you with the knowledge and insights you need to start growing mushrooms using liquid cultures. Follow the detailed instructions in this guide to make agar plates, and grain spawn.

Choose Your Method

Growing On Agar Using Liquid Cultures

Agar agar, mixed with a simple sugar (like malt extract) can be used to propagate, preserve and expand mushroom cultures.

liquid culture to agar

What Is Agar, and how is it made?

Agar may seem daunting but it’s simple really. It’s comes down to a mixture of water, agar agar powder, light malt extract (or honey) — this mix gets cooked in a pressurized vessel at 15 psi for 20 – 30 minutes.

The agar recipe is sterilized in a large glass medium bottle. (which is just fancy bottle we use in the laboratory) Once the growing medium is sterilized it goes to cool in a clean room, in front of an industrial grade air HEPA air scrubber, known as a flow hood.

Once the agar agar mixture cools to the ideal temperature (50 – 60 C) it can be poured into petri dishes or similar air-tight containers that are suitable for propogating mycelium. (we call these agar plates)

Get A 3-Pack of Pre-Made Agar

With our pre-made agar plates you can rest assured that your mycelium will have a strong foundation. Agar can be used to expand your production capabilities significantly, and as a vessel to store your genetics.

How To Use A Liquid Culture For Growing Mushrooms on Agar

Now that you have your liquid culture (and your agar plate) you can propagate a culture of your very own. The process is really easy to do – but you need to focus on keeping things clean!

What You'll Need

  • Clean Working Space
  • Butane Torch or Lighter
  • Agar Plate(s)
  • Liquid Culture Syringe
  • Gloves
  • N-95 Mask
  • Micro-pore tape (optional)

Find A Suitable Working Space

The right place to propagate your mycelium is one that is free of drafts, dirt and contamination. You can do this just about anywhere in your home but a smaller room with no furnace vents is best. You can also turn the furnace fans off for the transfer. (if you don’t have a small room or closet to work from)

Clean! Clean! Clean!

Ensuring the space is clean will go a long way in preventing contamination. Use a household cleaner to clean the walls, floors, and working surfaces before hand. Once it’s clean you can use a solution of 5% bleach and water to ensure there are no bacteria living on any surfaces.

This goes the same for any tools you will be handling inside the room. And for yourself too – be freshly showered and wearing clean clothes at all times when working with mycelium.

Propagate The Agar Using a Liquid Culture syringe

Now, it’s time to begin to propagate your agar plate using your liquid culture. One thing to note, time is of the essence. The faster the transfer is done, the lower the risk of contamination.

In your still-air environment carefully use your liquid culture to place a single drop in the center of the agar. This can be tricky to get right at first, but don’t worry if you squirt a little too much liquid culture, because it will still work.

Follow these steps to ensure proper inoculation of your agar plates:

1. Prep Your Syringe


To prepare your syringe, remove it from the package and screw the needle onto the end of the syringe. Once that’s done, use your lighter or butane torch to heat up the needle until it is red hot.

2. Inoculate Your Agar Plate


Once the needle has cooled down, carefully open your agar plate and squeeze a single drop of liquid culture into the centre of the plate. You don’t need much to get the culture going, just a single drop is all it takes. Close up the plate quickly to avoid airborne contamination.

Starting multiple plates at the same time is possible. In between transfers, sterilize your needle by getting it red hot again. Once it’s cool you can repeat this step for as many agar plates as you’d like.

3. Seal And Incubate


Now that the transfer is done and your plates are closed, you should seal them with micro-pore tape. Tear off a strip of micro-pore tape and seal all the way around the petri dish.

To properly incubate your agar, keep it in a dark place, at a temperature between 70 F – 80 F. Colder temperatures will still work but growth will be slow. Hotter temperatures might kill your mycelium culture, so be mindful of this, and keep it in the proper range.

Growing On Grain Spawn With Liquid Culture

Grain spawn is used by commercial growers to propagate bulk substrates for growing mushrooms. The grains can be almost anything, including rice, oats, corn, rye berries,  and the list goes on.

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What is Grain Spawn And How is It Made?

Grain spawn is the primary growing medium used by growers to make bulk substrate used for fruiting mushrooms. The grains provide nutrition to the mycelium so it can develop, but they also act as a convenient delivery tool.

They type of grain you use depends mostly on availability, however, some of the more commonly used grains are rye berries, millet, brown rice and corn. You can get pretty experimental with this an some growers have reported success growing on wild bird seed.

Once the grains are fully colonized by the mycelium, they can be used to inoculate your bulk growing medium of choice. As I said earlier, the grain makes a convenient delivery tool. Before the inoculation takes place, the grains inside the bag are broken apart and shaken to ensure the mucelium can spread easily into the new growing medium.

How Can I make My Own Grain Spawn?

In order to make your own sterilized grain spawn you will need to hydrate your grains and pressure cook them at 15 PSI until a core temperature of 227 F is reached.

What You'll Need

  • Clean Working Space
  • Poly Bags or Glass Jars
  • Poly Bag Sealer or Zip Tie(s)
  • Liquid Culture Syringe
  • Grains or Seeds
  • Gypsum
  • Gloves
  • N-95 Mask
  • Micro-pore tape
  • Pressure Cooker or Canner

Preparing your grains for sterilization

In order to use grain as a growing medium it must first be sterilized using a pressure cooker. The process involves hydrating the grains and bringing them to the appropriate heat for proper sterilization. (227 F)

We typically use Rye Berries as our grain of choice. It’s an easy material to work with, and readily available, so that’s why we use them for making grain spawn. Our recipe might be different from the others, but the key to our success and profitability is the simplicity of how to prepare it.

No Soak Grain Spawn Method and Recipe

1. measure grains & water by volume

To measure your grains for making our no-soak grain spawn is super simple. Take two parts grain, in our case this is two (2) 750ml scoops of dry grain for a total of 1500ml, and add that to your grow bag or glass jar.

Measuring the water is also simple. Add one (1) part water to the bag, which in this case would be 750ml or one scoop of water. This can work for any size bag you want to make just remember that the ratio is 2:1. Two parts grain, and one part water.

2. Add Gypsum To The Mix

A lot of growers (myself included) add gypsum to the mixture as well. The perfect amount to add remains a relative mystery, but what I do know is that you do not need much. One tablespoon of gypsum in a 5lb grain spawn bag is plenty.

If you want to add gypsum, you can do it after you have mixed your grains and water, or before. It really doesn’t matter because in the end you are going to shake the contents of the bag all up and mix them together.

3. Sterilization Using A Pressure Cooker

Once your mixture is prepared, you can start the sterilization process. Fold the gussets on the bag tightly, or place a lid on your glass jar and screw it shut. Place the bags loosely (don’t cram things in, that’s never good) into the pressure cooker, and fill the cooker with water until it just barely touches the bottom of the grains.

Turn your pressure cooker on, and set it to 15 PSI. Doing this will raise the temperature of the steam inside the vessel so you can achieve proper sterilization temperatures. A big misconception here is that there is an exact amount of time that the grains need to be cooked for.

However, the real way to sterilize your grains is to bring them to a temperature of 227 F and hold it there for 10 minutes and you will have sterilized grain spawn to make your transfer with.

The reason why I say there is no prescribed time is because there are many variables to consider. How tightly is the pressure cooker packed? This will have an effect on the core temperature of the substrate. The only way to properly tell is by using a thermacouple temperature probe.

But who’s got time for that? Not me. So let’s assume you’ve loosely packed your vessel, bring the pressure up to 15 PSI and hold it there for 1.5 hrs and you should be golden. If you must cram it full to maximize time and effort, you will need to increase that time to 3 hrs to ensure that your materials have been properly sterilized.

What works for you, might not work for someone else and vica-versa. If you are regularly getting contamination you will want to double check this process and if you’re in doubt, increase your sterilzation time.

4. Inoculating your grain spawn with liquid culture

Similar to making Agar (at the start of the article) you will want to follow the exact same clean practices. It’s important to follow these protocols any time you are making a mycelium transfer of any kind.

Let your grains cool in the pressure cooker until they are at room temperature. This will take several hours, I tend to leave my grains in there overnight so I can be sure the material has cooled down properly.

Sterilize the tip of your syringe with a lighter or butane torch until it’s glowing red. Once it’s cooled down, squirt 3 cc of liquid culture into each 5 lb grain bag. Then, seal the bag using a poly bag sealer. If you don’t have one, you can twist the top of the bag and secure using a zip-tie.

Once the bag is inoculated and sealed, give the grains a vigorous shaking to distribute the mycelium all over. This will also mix in your gypsum and will even out the final moisture content in the spawn bags.

5. Incubating Your Spawn

Incubating your newly inoculated grain spawn can take anywhere from 2 weeks to 1 month. Ensuring proper airflow (space around the bags) will help speed up the process. Temperature is another important factor, and the ideal air temperature range is between 65 F and 75 F.

Colder temperatures will result in slower growth, but that can also have a positive impact on contamination rates. Warmer temperatures will help give the mycelium a boost, but you want to be careful with this. Because mycelium produces heat, the inside of the bag will always (not sometimes) be warmer than the surrounding air, and this can cause things to go south if your ambient temperatures are too high.

Once you notice your grains are about 30%-40% colonized with fuzzy, white mycelium after 1 – 2 weeks of colonization, it’s time for a crucial step. Give the bag a vigorous shaking to redistribute the mycelium. This simple action promotes even growth and significantly reduces the time your grains take to fully colonize, a key to successful cultivation.

Uncle Ben's Tek - A Low Tech Approach

If you don’t have access to a pressure cooker, there is a way to get around it with relatively high success rates. It’s called Uncle Ben’s Tek. (yes, the minute rice!) Many people have successfully cultivated mushrooms using prepackaged Uncle Ben’s rice.

Let’s Take A Look At Uncle Ben’s Tek, Shall We.

What You Will Need

  • Uncle Ben’s Ready Rice (pre-steamed brown rice)
  • Liquid Culture Syringe
  • Micro-Pore Tape
  • Lighter or Butane Torch
  • 70% Alcohol
  • Distilled or Filtered Water
growing mushrooms on uncle ben's rice

How To Inoculate Uncle Ben's Rice Using A Liquid Culture?

This is the simplest way to make grain spawn. All you need to do is clean the pouch with alcohol. Then, flame sterilize your syringe and inject approx 3cc of liquid culture by poking a hole anywhere in the bag.

Moving the syringe in circles while you squirt in the liquid culture will help spread it around evenly. Remove the syringe, cover the hole with micropore tape, and you’re almost done.

Now you need to cut the top corner off the bag and immediately cover it with micro-pore tape. This will allow some air to exchange inside the bag which is crucial to the healthy development of mycelium.

It’s time now to give the bag a final shaking and set it in a dark place with colinization temperatures of 65 F – 75 F for a period of up to four weeks.

Making Liquid Culture, Using Liquid Culture

Making your own liquid culture is an involved process but it can be a rewarding one. Using your own liquid culture can save you money in the long run. Let’s see just how you can do it.

What is it, and How is It Made?

Liquid cultures are a growing media that is commonly used by mushroom farmer’s because it’s relatively easy to use, can be produced in mass quantities, and can help you streamline grain spawn production.

Basically, the media is a mixture of purified, or distilled water and sugar. You can use almost any sugar, but one that’s commonly used, is honey. (yes, pure honey) Due to it’s antibacterial properties, honey is a great choice for making your own liquid culture from scratch.

Read Our Blog Article About Making Liquid Culture Using Honey

Instead of going in-depth on how to make liquid cultures, please read the above article which explains everything you need to know.

Pick Your Strain

Mystery King Oyster Mushroom Liquid Culture 3cc
King Blue Oyster Mushroom Liquid Culture 3cc
Turkey Tail Mushroom Liquid Culture 3cc
Black Oyster Mushroom Liquid Culture 3cc
Lion’s Mane Liquid Culture 3cc
Antler Reishi Liquid Culture 3cc

You Are Well on Your Way To Being An Expert On Using Liquid Cultures!

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learn more about growing mushrooms

Interested in learning more? Our detailed mushroom growing guide can teach you the basics and some advanced techniques to help you get the best results possible. Explore this in-depth guide below.