The Original Rye Spawn Bags
The Original Rye Spawn Bags is backordered and will ship as soon as it is back in stock.
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The Original Rye Spawn Bags
Description
Description
The Original Rye Grain Spawn Bags (2-Pack)
Sterile Rye Berry Grain Spawn Bags for Reliable Mushroom Cultivation
Trusted since the 1970s, our Original Rye Grain Spawn Bags are a classic choice for growers who want reliable, nutrient-rich grain spawn for mushroom cultivation. These sterile mushroom spawn bags are loaded with over 2 quarts of organic rye berries per bag—hydrated, pH-balanced, fortified with essential minerals, and professionally sterilized for clean inoculation.
Rye grain is one of the most widely used grains for mushroom spawn because it offers excellent moisture balance, consistent kernel size, and strong nutrient density. These rye berry grain spawn bags are ideal for colonizing with liquid culture or spores, then mixing into bulk substrate or using with monotub setups for larger bulk grows.
Our sterile rye spawn bags are soaked overnight, simmered, sealed, and pressure sterilized for 3 hours in our autoclave so they arrive ready for inoculation.
How to Inoculate & Colonize Rye Grain Spawn Bags
These sterilized grain bags are designed for simple, contamination-resistant inoculation using liquid culture or spore syringes. Each bag features a self-healing injection port and 0.22-micron filter patch for proper gas exchange during colonization.
After inoculation, incubate the bags in a clean, warm environment and allow the mycelium to fully colonize the rye grain. Once dense white growth is achieved, the spawn is ready for bulk substrate, monotub growing, or other fruiting setups.
Breaking Up Rye Spawn for Bulk Mushroom Grows
When fully colonized, rye grain spawn can be easily broken up and mixed into bulk substrate such as coco coir, manure-based blends, or Master’s Mix. This makes rye spawn ideal for monotubs, grow bins, and high-yield bulk cultivation methods.
Rye kernels separate cleanly and distribute evenly throughout the substrate, helping create multiple strong inoculation points for faster colonization and more uniform pin sets.
What’s Included
- 2 Original Rye Grain Spawn Bags (2.25–2.5 lbs each)
- Cereal-grade organic rye berries, mineral water, gypsum, and nutrient-enhancing herbs
- Self-healing high-temperature injection ports for sterile inoculation
- 3mm polypropylene bags with 0.22-micron filter patches for optimal gas exchange
- Step-by-step photo guide + instructional videos
Why Choose Our Rye Grain Spawn Bags?
-
Classic Rye Berry Performance
Rye berries provide excellent moisture balance, nutrient density, and consistent grain structure for reliable colonization. -
Sterile & Ready to Use
Each bag is soaked, simmered, sealed, and pressure sterilized in-house so it arrives ready for clean inoculation. -
Great for Bulk & Monotub Growing
Rye spawn breaks apart cleanly and mixes evenly into substrate for monotubs, grow bins, and bulk growing methods. -
Strong Second and Third Flush Potential
The nutrient-rich rye grain base supports vigorous mycelium growth and strong performance through later flushes. -
Contamination-Resistant Design
Filter patches and high-mounted injection ports help reduce handling errors and support healthy gas exchange.
Pro Tips for Best Results
Using sterile technique, inject 5–7 cc of liquid culture or spores directly into the injection port. Keep the bag in a clean, warm area around 72–76°F during colonization. Once initial mycelium growth is established, gently mix or massage the grain when appropriate to speed up grain-to-grain spread.
Once fully colonized, break up the rye spawn and transfer it into bulk substrate for maximum yields. These rye spawn bags pair perfectly with monotubs, bulk substrate blocks, and high-humidity fruiting environments.
New to Grain Spawn?
Learn exactly how to inoculate, incubate, and fully colonize your spawn bags or grain jars with our step-by-step guide.
Read the Full Guide →
Let customers speak for us
I love the people and the products. The people at MWGK clearly care about the integrity of the community they serve.
The monotub works amazing only had it a couple of weeks and about to have second harvest I used AIO grow bag for first flush and move to tub for second and its great not having to watch 24/7. Thanks Midwest
Four days after mixing grain, Select substrate, and the Midwest horse manure booster - the results speak for themselves.
It has everything you need for a fast, large flush success with fewer moving parts than a standard monotub. It is a surprisingly versatile option for more advanced students. Pic is 5 grain jar at 8 days. GT LM This is where I shop, now.
Rich, perfectly field-wet, sterile and it is perfect for those many varieties that won’t thrive quite as well in Bulk Substrate and Casing Mix, which I’ve seen as best for psilocybes/cyanescens. I’m using it for the first time with Lions Mane and King Trumpets. So far so good, 7 days and primordial and pins are starting to flourish. It drains better and is lighter than MGK’s Bulk Casing and Substrate. Great product.
Love the heater and how even and exact it heats. I set mine to 76 degrees and my room fluctuates from 64-75 and it holds solid at 75 degrees. I used a probe thermometer to double check the substrate level temp and its exactly 1 degree less than the heater setting. Another tip, I only needed to use the round monotub thermometer to check my humidity levels every so often. I would leave a filter disk on that hole instead of the thermometer. The only time it came in handy was after my first flush when humidity started to drop. I was able to use that gauge and check whether I needed to mist. Overall great kit and worth the money!
Ive bought mutiple jars before i came up with my own recipe, every jar produced healthy cultures, even if ones damaged in shipping they replace immediately, highly recommend
Very small chance that you get a contaminate you already had it and you’re either culture spores etc. their stuff is 100% sterile every time 100% of the time everything is viable never had a problem been shopping with them for sometime
It’s very good product and I highly recommend it to everyone.👏👏👏
I love my magnetic stir plate it works great for Liquid culture jars.
My bag had a slow start, but excellent finish. Oak Ridge.
Great product for my cannabis best deal around arrived fast thank you Midwest grow kits definitely will be purchasing again
So far it seems very sturdy and I will give another review after I fill her up. Im just getting started with this life changing hobby and this will hold up strong
It was a price commitment, however it equated to less than I would spend on most any DIY project. I decided to purchase it and have since done spore work, agar transfers to agar and grain, culture to spawn bag inoculations, cloming and prints all with a 0% contamination rate. I practice about as good a sterile technique as I can mustard, considering I perform all my work on my kitchen table. Im consistently amazed by how flawless everything has turned out since adding this to my operations. I consider it indispensable. Instead of the double sided tape provided, i purchased some plastic velcro tape from the Gnome Depot and use it to affix the pvc guards to the sides. When i am done, i have also made it so i can sandwich them together and store them one the front to protect that precious filter when not in use. If you can swing it, buy it. Takes the risk out of procedure. Im bummed i cheaped out on the stainless riser offered at a discount with purchase of the LFH. That would have been exceedingly useful, but I have since utilized a baking drying rack to much success. Now go forth and frolic in the dung!
This is really built well, simple to operate, so happy to have some control of fruiting conditions finally.
