Midwest Grow Kits
Premium Quick-Colonizing 5-grain Jar (32oz)
Premium Quick-Colonizing 5-grain Jar (32oz)
Premium Quick-Colonizing 5-Grain Spawn Jar (32oz Wide Mouth)
Sterile Grain Spawn Jar for Fast Colonization, Easy Inoculation & Bulk Growing
Get faster, more reliable growth with the Midwest Grow Kits Premium 5-Grain Spawn Jar. This 32oz wide mouth sterile grain jar is designed for growers who want easy inoculation, dependable colonization, and strong performance for monotubs, bulk substrate, and other mushroom cultivation projects.
Each jar is filled with a carefully balanced 5-grain mushroom spawn blend made from rye berries, white milo, red milo, white millet, and red millet. This mix provides a range of grain sizes that creates more inoculation points, helping support rapid mycelium spread and more aggressive colonization compared to single-grain jars or larger bulk containers.
Why growers like 5-grain jars: Grain spawn jars can be more reliable and faster colonizing for beginners because the smaller grain volume is easy to monitor, easy to shake, and often colonizes quickly with less guesswork.
Why Choose Our 5-Grain Spawn Jar?
- Fast Colonization Potential – Multiple grain sizes create more inoculation points for strong, even growth.
- Beginner-Friendly – Grain jars are easy to monitor and often more reliable for first-time growers.
- Clean & Easy Inoculation – Self-healing injection port makes spore syringe or liquid culture use simple.
- Reliable Gas Exchange – Each lid includes a 0.22 micron filter disk for healthy airflow.
- Sterile & Ready to Use – Professionally sterilized and prepared for immediate inoculation.
- Great for Bulk Growing – Ideal for mixing with casing mix or bulk substrate in monotubs.
What’s Included
- One (1) 32oz Wide Mouth Glass Spawn Jar
-
Premium 5-Grain Blend made with:
- Rye berries
- White milo
- Red milo
- White millet
- Red millet
- Gypsum & Calcium Phosphate for improved grain performance
- 0.22 Micron Filter Disk for gas exchange
- Self-Healing Injection Port for clean inoculation
- Sterilized at 15 PSI for 120 Minutes
Product Specifications
| Component | Details |
|---|---|
| Jar Size | 32oz Wide Mouth Glass Jar |
| Pack Size | Single Jar |
| Grain Blend | Rye berries, white milo, red milo, white millet, red millet |
| Additives | Gypsum and calcium phosphate |
| Filter Type | 0.22 micron filter disk |
| Injection Port | Self-healing port for spores or liquid culture |
| Sterilization | 15 PSI for 120 minutes |
| Recommended Inoculation | 3–4cc per jar |
Recommended Usage Chart
Use this quick chart as a general guide when planning your grow.
| Application | Recommended Amount | Notes |
|---|---|---|
| Spore Syringe per Jar | 3–4cc | Inject through the self-healing port for clean inoculation |
| Liquid Culture per Jar | 5–7cc | Ideal for faster colonization when using clean culture |
| Bulk Substrate Ratio | 1–2 jars per 5 lbs of casing mix | Use based on desired spawn-to-substrate ratio and colonization speed |
| Typical Monotub Use | 2–3 jars per monotub | Varies by tub size and substrate depth |
| Best Use Case | Monotubs, trays, bulk grows | Excellent for expanding colonized grain into larger fruiting setups |
Designed for Faster Colonization
Unlike single-grain jars, this premium blend combines both larger and smaller grains to help distribute inoculant more effectively and support faster colonization throughout the jar. The result is a vigorous grain spawn jar that is easy to shake, easy to expand, and ideal for growers who want dependable performance.
These mushroom grain jars are especially well-suited for growers moving into bulk substrate cultivation and monotub growing, where strong grain spawn can make a major difference in colonization speed and overall success. If you prefer larger-scale inoculation, you can also explore our spawn bags collection.
From Jar to Bulk Monotub Grow
The video below shows the process of inoculating a grain jar, allowing it to colonize, breaking it up, and mixing it with substrate for a bulk monotub grow.
Premium Grain Spawn Jar for Mushroom Cultivation
The Midwest Grow Kits Premium 5-Grain Spawn Jar gives growers a sterile, ready-to-use grain spawn option built for fast colonization and strong expansion into bulk substrate. Whether you are inoculating with spores or liquid culture, this jar is designed to simplify the process and improve consistency from start to finish.
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 →
- All-in-one, ready to grow
- Produces multiple flushes
- High-quality, USA-made
- Great for home or classroom use
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