Premium 5-Grain Spawn Bags | Sterile Grain Bags for Mushroom Cultivation
Premium 5-Grain Spawn Bags | Sterile Grain Bags for Mushroom Cultivation is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
Description
Description
Our Premium 5-Grain Spawn Bags are sterilized mushroom grain bags filled with a blend of rye, white and red milo, and white and red millet — mixed kernel sizes that spread through bulk substrate for more inoculation points. Each 2-pack holds two 2.25–2.5 lb bags with a 0.22 micron filter patch and a self-healing injection port.
This has been our best-selling spawn for more than a decade. Every batch is made fresh in-house: the grain is soaked, simmered and surface-dried to cut down on clumping, hydrated with a fortified mineral blend, then pressure-sterilized so it arrives ready for your liquid culture or spores.
- 2 bagsPer pack
- 2.25–2.5 lbsPer bag
- 5 grainsRye, milo, millet
- 0.22 µmFilter patch
- 3 hrsSterilized, 18 PSI
Why growers pick 5-grain spawn
- More inoculation points – Small millet and milo kernels fill the gaps between larger rye berries, so the spawn spreads more evenly through substrate.
- Less clumping – Grains are soaked, simmered and dried before bagging, so colonized spawn breaks apart cleanly.
- Fortified hydration – Blended RO and mineral water with gypsum, Calcium+ and DAP for balanced pH and nutrients.
- Built for bulk – Mixes evenly into coir, manure-based and other bulk substrates for monotubs and larger fruiting setups.
- Proven for 10+ years – A customer favorite with beginners and experienced bulk growers alike.
Inoculating and colonizing a 5-grain spawn bag.
What's in the pack
- 2 × Premium 5-Grain Spawn Bags, 2.25–2.5 lbs each (about 2 quarts)
- Unicorn 10T polypropylene bags, 3 mil, with a 0.22 micron filter patch
- High-temperature self-healing injection port on every bag
- Step-by-step photo grow guide plus advanced bulk grow instructions
How to use them
- Prep. Wipe the injection port with alcohol and use a sterile needle and syringe.
- Inoculate. Inject 5cc of spore solution or 7–10cc of liquid culture through the self-healing port. Not sure how many syringes to buy? Use our syringe calculator.
- Incubate. Keep the bag at 72–76°F, out of direct light and undisturbed, until mycelium is clearly growing.
- Break and shake. At about 25–30% colonization, gently break up and massage the grain to spread the mycelium, then let it finish colonizing.
- Spawn to bulk. Once the bag is fully white, break it up and mix it evenly into pasteurized bulk substrate in your monotub.
Breaking up colonized spawn and mixing it into bulk substrate.
How much spawn for your monotub?
A good starting ratio is about 1 part grain to 3 parts bulk substrate.
| Monotub | Spawn bags | Bulk substrate |
|---|---|---|
| Small 28Q | ½ bag | 4–5 lbs |
| Medium 44Q | 1 bag | 7.5 lbs |
| Large 66Q | 2 bags (this 2-pack) | Up to 10 lbs |
5-Grain vs. Original Rye
| Spawn bag | Grain | Kernel size | Best for |
|---|---|---|---|
| Premium 5-Grain (this bag) | Rye, white & red milo, white & red millet | Mixed small and large | Even spread through bulk substrate |
| Original Rye | Organic rye berries | Uniform, larger kernels | Classic single-grain spawn |
Specifications
| Specification | Detail |
|---|---|
| Grain blend | Rye berries, white milo, red milo, white millet, red millet |
| Weight | 2.25–2.5 lbs per bag (about 2 quarts) |
| Pack size | 2 bags |
| Hydration | RO + mineral water with gypsum, Calcium+ and DAP |
| Sterilization | Autoclaved at 18 PSI for 180 minutes |
| Bag | Unicorn 10T polypropylene, 3 mil |
| Filter patch | 0.22 micron |
| Injection port | High-temp self-healing |
| Inoculation | 5cc spores or 7–10cc liquid culture |
| Incubation | 72–76°F |
| Shelf life | Best within 90 days; up to 120 days refrigerated |
Storage: Every bag is made fresh. Inoculate within 90 days for best results, or refrigerate unopened bags to keep them up to 120 days.
New to grain spawn? Our Spawn Bag & Grain Jar Guide walks through inoculating, incubating and fully colonizing spawn bags and grain jars step by step.
Pair it withMix colonized spawn into bulk substrate in a monotub, or compare with our Original Rye Spawn Bags.
Common questions
What grains are in the 5-grain blend?
Rye berries, white milo, red milo, white millet and red millet. The mix of kernel sizes gives more inoculation points when you spawn to bulk.
How much liquid culture or spore solution should I use?
Inject 5cc of spore solution or 7–10cc of liquid culture through the self-healing injection port. Wipe the port with alcohol and use a sterile needle first.
When should I break and shake the bag?
At about 25–30% colonization. Gently break up and massage the grain to spread the mycelium, then let the bag finish colonizing.
How much substrate does one bag go into?
About 7.5 lbs of bulk substrate, which fills a Medium 44Q monotub. Use both bags for a Large 66Q with up to 10 lbs of substrate.
How long do unopened bags keep?
They are made fresh. Use them within 90 days for best results, or refrigerate them to keep them up to 120 days.
Should I choose 5-grain or rye?
Both are sterilized in-house and inoculate the same way. The 5-grain blend has mixed kernel sizes for more inoculation points; rye is the classic single-grain spawn with uniform, larger kernels.
Our Growing Experts Recommend
Products our growers commonly use with this item
