GrowFast Grain (2-Pack)

$20.00
Sold Out

Media: Rye Berries
Bag weight: (2) 3 lbs

  • 3mm Polypropylene bags with 0.22-micron filter patch

  • Self-healing high-temperature injection port

Our top-selling sterilized grain spawn bag, meticulously designed by mycologists, is engineered to optimize the speed and yield of your mushroom cultivation. All you need is a spore syringe or liquid culture to get started!

Inside each of our spawn bags, you'll find our exclusive grain blend featuring hydrated, nutrient-rich organic rye berries. These bags are equipped with a self-healing injection port, allowing seamless use with spore or culture syringes. They also have a 0.2-micron filter patch that blocks airborne contaminants while ensuring consistent gas exchange. Please note that the color of the injection port may vary.

Spawn to Bulk Ratio
For optimal results, we recommend using 1.5 lbs of fully colonized grain spawn for every 5 pounds of bulk substrate—approximately a 1:3.3 ratio. For liquid culture or spore solution, we recommend injecting 2.5 to 5 cc per 3-pound substrate bag. (Refer to the Inoculation and Colonization section below for complete instructions.)

The Advantages of Rye Berries
When it comes to mushroom cultivation, the choice of grain spawn substrate plays a pivotal role in determining success. Rye berries, known for their exceptional qualities, stand out as an ideal choice for your mycological endeavors.

Sterilization Excellence
Our California Ambrosia grain spawn bags undergo sterilization in a commercial-grade autoclave. We meticulously verify sterility using biological indicators and temperature sensors, ensuring the utmost quality and consistency.


Shipping Note: If your order exceeds 100 pounds, the shipping cost at checkout will display as FREE ($0.00). This does not mean free shipping. We’ll follow up after your order to provide a delivery quote and arrange payment before we fulfill it.

Media: Rye Berries
Bag weight: (2) 3 lbs

  • 3mm Polypropylene bags with 0.22-micron filter patch

  • Self-healing high-temperature injection port

Our top-selling sterilized grain spawn bag, meticulously designed by mycologists, is engineered to optimize the speed and yield of your mushroom cultivation. All you need is a spore syringe or liquid culture to get started!

Inside each of our spawn bags, you'll find our exclusive grain blend featuring hydrated, nutrient-rich organic rye berries. These bags are equipped with a self-healing injection port, allowing seamless use with spore or culture syringes. They also have a 0.2-micron filter patch that blocks airborne contaminants while ensuring consistent gas exchange. Please note that the color of the injection port may vary.

Spawn to Bulk Ratio
For optimal results, we recommend using 1.5 lbs of fully colonized grain spawn for every 5 pounds of bulk substrate—approximately a 1:3.3 ratio. For liquid culture or spore solution, we recommend injecting 2.5 to 5 cc per 3-pound substrate bag. (Refer to the Inoculation and Colonization section below for complete instructions.)

The Advantages of Rye Berries
When it comes to mushroom cultivation, the choice of grain spawn substrate plays a pivotal role in determining success. Rye berries, known for their exceptional qualities, stand out as an ideal choice for your mycological endeavors.

Sterilization Excellence
Our California Ambrosia grain spawn bags undergo sterilization in a commercial-grade autoclave. We meticulously verify sterility using biological indicators and temperature sensors, ensuring the utmost quality and consistency.


Shipping Note: If your order exceeds 100 pounds, the shipping cost at checkout will display as FREE ($0.00). This does not mean free shipping. We’ll follow up after your order to provide a delivery quote and arrange payment before we fulfill it.

  • Orders that weigh more than 100 lbs qualify for flat-rate shipping. If your cart exceeds that weight, we will contact you to confirm the delivery costs before processing your order.ption

  • To initiate the inoculation of the grain bag, simply insert your spore or culture syringe through the port in a sterile environment. We always advise the use of clean hands and latex or nitrile gloves to minimize the risk of introducing contaminants.

    As a best practice, we recommend waiting at least one week after receiving your shipment before injecting the grain bags. This precaution ensures that the bags have not been compromised during transit. Please rest assured that your purchase is backed by a 100% guarantee. If your bag shows any signs of compromise, we will promptly replace it.

    For optimal results, we suggest using 2.5-5ccs of spore solution per 3lb injection port bag. It's generally not advisable to use an entire syringe in a single bag, as this can introduce excess moisture, potentially leading to over-saturation within the bag. Over-saturation can result in pooling and create anaerobic conditions that make it challenging for the mycelium to colonize effectively.

  • Allow your bag to undergo colonization in a cool, shaded location, shielded from direct sunlight. Maintain an incubation temperature within the range of 55 to 75 degrees Fahrenheit. After a few weeks, you should begin to observe the mycelium's growth on the grain.

    You'll notice the pristine white mycelium extending outward from the injection point. When it has expanded to a length of three to four inches, you should, without opening the bag, delicately break up the colonized grain and thoroughly mix it into the uncolonized grain. This step significantly accelerates the colonization process.

    Once the bag has transformed into a solid white mass of mycelium, your spawn is ready for use. The timeframe for this achievement can vary, typically taking a few weeks to a month or possibly longer, depending on the specific mushroom species and the vitality of your culture.

  • Grain bags should be stored at room temperature out of direct sunlight. No refrigeration is necessary. They can also be stored for several months before use.

  • California Ambrosia’s products are intended solely for lawful purposes.