Video by Fresh from the Farm Fungi
Mastering Grain Spawn for Mushroom Cultivation: A Step-by-Step Guide
For those serious about growing gourmet mushrooms efficiently, understanding how to create your own grain spawn is essential. While it might seem intuitive to go straight from spores to bulk substrate, taking the extra step of making high-quality grain spawn first will exponentially accelerate mycelium growth. In this guide, we’ll cover why you should make grain spawn in-house, how to source and prepare your grain, and a special technique to optimize your mushroom yield.
Why Make Your Own Grain Spawn?
While purchasing pre-made grain spawn is an option, it can significantly cut into your profit margins and leave you dependent on suppliers. By learning to make your own, you gain complete control over quality, timing, and costs. With proper techniques, producing grain spawn in-house becomes a cost-effective and scalable process.
Sourcing Grain Spawn
The first step in making grain spawn is sourcing the right grains.
Raw Grains from Suppliers
- The best option is purchasing raw grains from Mushroom Media Online. We source our grains from direct suppliers and make certain of the quality and condition of the grains we sell. Getting deliveries to your farm makes life and your farm production easier.
- You can deal with local farm supply stores as well. The downside is availability in many regions and your time. Every time you must get in your car or truck and leave production to shop you are wasting your time that could be spent growing your business.
A quick thought on delivery items. I used to take a break from what I was doing and leave the house or my office to go get lunch or run a few errands. I think most of it was I liked the break. When I stopped and realized the time I was losing out of my workday or progress on a project it changed my business life first, and later my personal life.
Now maybe once a week when I am working on a project, I will order Door Dash for lunch or dinner. It takes me 3 minutes to order online and saves me more than 1 hour of drive time, time waiting for the food, (even if I got it to go). The most important part is that it does not mess up my rhythm and progress. In my youth I worked for a Japanese manufacturer in my hometown. It was a great company and I had amazing friends at work. One of their core beliefs was called “Just in time” this was a production belief of getting your supply lines so dialed in that when you needed your next box of parts it would arrive and be delivered to the production area just in time. This meant that you needed to set up your supply lines of materials to make this possible. It enabled you to be much more productive in getting things built. Well, the great news is that it can work for your farm too. Increasing productivity and decreasing your time on mundane tasks is critical to growing and scaling your farm.
Get what you need delivered and save the time and hassel. You will get better supplies, save time, and be much more productive.
Back to grain spawn.
Preparing Your Grain Spawn
Once you have sourced your grains, the next step is preparing them for sterilization. There are three primary methods for hydrating grain spawn:
- Overnight Soak and Sterilization
- The easiest and most energy-efficient method involves soaking the grain overnight. This allows the grain to reach field capacity by absorbing water passively. After soaking, rinse the grains to remove excess water before bagging and sterilizing.
- Soak, Simmer, and Sterilize
- If you need to speed up hydration, you can soak and then simmer the grains. Fill a large pot with grains and water, ensuring an ample water level to compensate for absorption. Bring it to a boil for about 20-30 minutes. Be cautious not to overcook, as bursting grains expose inner nutrients that attract contaminants.
- No Soak, No Simmer Method
- This technique skips pre-hydration by adding a calculated amount of dry grain and water directly to sterilization bags. During sterilization, the heat hydrates the grains to an optimal 60-65% moisture level. This method is highly efficient but requires precise measurements tailored to each type of grain.
Choosing Between Grain Jars and Grain Bags
After preparing your grain, you need to decide whether to use jars or bags for colonization.
- Jars:
- Reusable and eco-friendly, but require cleaning and can slow down production.
- Ideal for small-scale operations or those prioritizing sustainability.
- Bags:
- Disposable and efficient but slightly longer colonization times.
- Best for large-scale operations needing high throughput.
Some farmers opt for a hybrid approach, using both jars and bags strategically.
Optimizing Colonization with a Hybrid Method
A special technique for improving consistency and efficiency in mycelium growth involves a two-step colonization process:
- Start with Half-Pint Jars – Allow them to fully colonize before expanding into larger bags.
- Transfer to 5-Pound Bags – Once the jars are colonized, they serve as a more reliable inoculant for larger grain bags.
This method ensures a more predictable colonization timeline, reducing variability in growth cycles. By implementing a half-step between jars and bulk grain bags, you create a more uniform harvest schedule—especially useful if selling at farmer’s markets or planning commercial production.
Making your own grain spawn may take some time to master, but the benefits far outweigh the challenges. By sourcing the right grains, choosing the best preparation method, and optimizing your colonization process, you can achieve consistent, high-yielding mushroom growth. Whether you’re growing mushrooms for personal use or market sales, investing in your grain spawn process is a game-changer.