If you are weighing sterilized substrate bag vs Mushy Substrates style options for your next bulk run, you are really deciding how much nutrition, volume and prep help you want in one bag. In this head to head we compare North Spore ‘Boomr Bag’ Sterile Mushroom Bulk against 10 LBS Coco Mushroom Substrate with Added Cow to match the right bag to your monotub plan and growing style.
Both are pre sterilized, pre hydrated and built to mix with colonized grain for monotubs or grow in the bag fruiting, yet they take different paths to colonization and yield. Updated for November 2026, this guide breaks down blend philosophy, bag size, sterility workflow and buyer guidance for Substrate, CVG and Bulk Amendments growers, so you can choose with confidence whether you run small trays or large bulk tubs.
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Quick Picks at a Glance
Prime Mushroom Merchant CVG Substrate 5 lb
Prime SGM LABS 10 LB Coco Mushroom Substrate CVG
Prime SGM LABS 5 LB Black Coco Mushroom Substrate
Prime North Spore Organic Sterilized Mushroom Grain Bag
Prime North Spore Boomr Bag 5 lb Sterile Manure-Based
Prime SPAWN DADDY 2 lb All-in-One Mushroom Grow Bag
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Pros
- Pre-sterilized and pre-hydrated to save prep time and reduce contamination risk
- Simple three ingredient CVG formula with no manure or chemical additives
- Compatible with monotubs, grow bags and common bulk growing methods
- Sturdy grow bag packaging for clean handling and storage
Cons
- 5 lb bag may only cover one monotub, so larger grows will need multiple bags
- Requires separately prepared colonized grain, it is not an all in one grow kit
- Manure free formula is cleaner but may yield less than nutrient enriched substrates for advanced growers
Mushroom Merchant CVG Substrate is a 5 pound ready to use bulk substrate made from coco coir, vermiculite and gypsum. It is designed for hobbyists and first time growers who want to mix colonized grain with bulk substrate in monotubs or grow bags.
The standout benefit is convenience. It arrives pre-sterilized and hydrated, so you can skip pasteurization and field capacity testing. In use, the coco coir holds moisture, vermiculite keeps the mix airy, and gypsum supports structure for steady colonization.
Build quality is simple but practical. The blend is clean, consistent and free of manure or added chemicals, which helps control odor indoors. It comes packed in a durable grow bag that makes pouring, mixing and storage cleaner than loose bags or buckets.
The main tradeoffs are size and scope. One bag suits a single tub or small batch, so big projects need more. You will also need to supply your own prepared grain spawn, and growers seeking maximum yields may prefer manure enriched mixes.
Overall, this is a reliable, beginner friendly option for clean bulk growing. If you want a low prep, low mess CVG that works with standard methods, it is an easy choice for monotub and grow bag setups.
Brand: Mushroom Merchant, Style: Modern, Weight: 5 pounds, Packs: 1.
Ingredients: Coco coir, vermiculite and gypsum with no manure or additives.
Format: Pre-sterilized, hydrated bulk substrate supplied in a durable grow bag for monotubs and grow bags.
Start with fully colonized grain spawn prepared separately. Open the grow bag and mix the CVG evenly with grain using clean hands and sanitized tools.
Load the mixture into your monotub or grow bag, level the surface and close for colonization. Maintain proper humidity and fresh air exchange for fruiting per your chosen bulk method.
Pros
- Perfectly hydrated out of the bag with no prep work required
- Clean sterilized substrate with strong resistance to contamination
- Fast colonization reported by beginner and experienced growers
- Flexible use in monotubs, as casing, or in bag growing
- Quality CVG plus cow manure for improved nutrition and yields
Cons
- Spawned grain must be purchased separately to start growing
- 10 lb size may require multiple bags for large monotubs or bulk runs
- Sterility depends on careful handling once the bag is opened
This 10 lb Cow Coco substrate from SGM LABS is a sterilized CVG mix made for mushroom fruiting in monotubs, as casing, or directly in the bag. It is built for first time growers, hobbyists, and bulk cultivators who want a ready to use solution without mixing their own substrate.
The blend combines coco coir, cow manure, vermiculite, and gypsum to supply nutrition, moisture retention, and structure for mycelium growth. In real world use, growers report fast colonization, ideal hydration, and clean runs with no contamination when good sterile technique is followed.
Build quality centers on the pre-hydrated 0.2 micron filter bag that keeps the substrate sterile until you are ready to inoculate. The 10 pound, 7 liter fill provides solid volume for standard tubs while staying manageable to pour, mix, and store.
There are a few limits to plan for, including the need to supply your own spawned grain and maintain sterility after opening. Large scale grows may need multiple bags, and the bag is bulky to handle and store compared to dry compressed bricks.
Overall, this is a reliable, beginner friendly, high yield substrate that removes guesswork from prep and hydration. If you want consistent moisture, clean performance, and flexible growing options, it is an excellent choice for your next run.
Brand: SGM LABS, Item Type: Cow Coco CVG Substrate, Weight: 10 pounds
Volume: 7 liters, Unit Count: 160 fluid ounces, Style: Modern
Material Blend: Coco coir, cow manure, vermiculite and gypsum, Bag Filter: 0.2 micron sterilized fruiting bag
Use Methods: Monotub fill, casing layer, or grow in bag, Manufacturer Part Number: 10lbcowcocosubstrate
Pros
- Proven CVG blend balances moisture retention, aeration and nutrition for strong colonization
- Truly ready to use with no prep, saving time and eliminating hydration mistakes
- Sterile packaging supports cleaner grows with less competition from contaminants
- Flexible application for monotubs, casing layers or in-bag fruiting
Cons
- Requires separate colonized grain spawn, it is not an all-in-one grow kit
- 5 pound bag may require multiple units for large bulk monotub runs
- Sterility depends on proper handling after opening, so clean technique is still essential
The SGM LABS 5 LB Black Coco Mushroom Substrate is a bulk CVG substrate built for spawned grain to fruit. It suits first time growers, hobbyists and bulk cultivators who want to skip mixing and pasteurizing at home.
Its standout is the classic coco coir, vermiculite and gypsum blend, pre-hydrated to field capacity for fast colonization. The vermiculite holds moisture while gypsum supports structure, which promotes even mycelium runs and fuller flushes.
Design centers on convenience and cleanliness. The substrate arrives sterilized in a 0.2 micron filter bag that limits exposure to contaminants while allowing proper gas exchange for healthy mycelium.
The main limitation is that it is substrate only, so you still need live grain spawn and good sterile technique. Larger monotub builds may also need more than one 5 pound bag for ideal depth.
Overall, this is a practical, time saving base for monotub, casing or grow in bag methods. If you want a clean, ready to pour CVG mix from a dedicated mushroom supplier, this is a solid pick.
Brand: SGM LABS, Style: mushroom grow bag, Item Type: bulk mushroom substrate.
Weight: 5 pounds, Volume: 80 fluid ounces, 240 cubic inches, CVG blend of coco coir, vermiculite and gypsum.
Packaging: Pre-hydrated and sterilized 0.2 micron filter bag, UPC: 712198404774, ASIN: B0CR9WXH4J.
Use as monotub fill by dumping the ready to use substrate into a clean tub and mixing with colonized grain. No additional hydration or pasteurization is required.
Use as a casing layer over colonized bulk or fruit directly in the bag by adding grain spawn to the CVG bag. Maintain clean hands, tools and fruiting conditions for best results.
Pros
- Certified organic, nutrient rich grain blend optimized for mycelial growth
- Beginner friendly, no pressure cooker or grain prep required
- Reliable sterilization and thoughtful bag design reduce contamination risk
- Versatile for most gourmet and dung loving species with manure or hardwood substrate
Cons
- Spore syringe or liquid culture and bulk substrate must be purchased separately
- Some batches may vary in moisture, which can slow colonization
- Single 3 pound bag is best for small grows, larger projects need multiple bags
The North Spore Organic Sterilized Mushroom Grain Bag is a 3 pound ready to inoculate spawn bag designed for home mycologists. It is built for beginners without autoclaves as well as small batch growers who want consistent results without prep work.
The standout is the proprietary millet and wheat berry blend, which offers more inoculation points and lower contamination risk than rye alone. In real world use, reviewers report fast, even colonization when paired with liquid culture and proper 1 to 5 spawn to substrate ratio.
Build quality is a clear strength, with commercial autoclave sterilization, biological verification, a self healing injection port and a 0.2 micron filter patch. The bag keeps grain hydrated and structurally intact while allowing clean gas exchange and easy syringe inoculation.
It is not perfect, as a few users report bags arriving dry or stalling, which highlights natural variability in living culture work. You will also need to buy spores or liquid culture and bulk substrate separately, and one bag is best for small to medium grows.
Overall, this is one of the most convenient and trustworthy ways to start grain spawn at home. If you value certified organic ingredients, proven sterility and beginner friendly design, this bag is an excellent foundation for manure or hardwood grows.
Inject 2.5 to 5cc of spore syringe or liquid culture through the self healing port using sterile technique. Keep the filter patch uncovered so the mycelium can breathe during incubation.
Store in a warm, dark place and gently mix once you see 20 to 30 percent colonization to speed full coverage. Allow the bag to fully colonize until the grain is white throughout with no uncolonized kernels.
Once fully colonized, mix thoroughly at a 1 to 5 ratio with sterilized manure or hardwood substrate for fruiting. Higher inoculation rates can improve speed and success, especially for beginners.
Brand: North Spore, 3 pound organic millet and wheat berry grain bag for mushroom cultivation. USDA Certified Organic and formulated by mycologists for maximum yield.
Includes self healing injection port and 0.2 micron filter patch for sterile gas exchange. Designed for use with spore syringe or liquid culture.
Recommended use: 1 lb colonized spawn per 5 lbs bulk manure or hardwood sterile substrate. For specific species and bulk recipes, follow standard spawn to bulk practices.
Pros
- Sterile and ready to use with no pasteurization, mixing or hydration required
- Formulated specifically for dung-loving species to support fast colonization and better yields
- Works across multiple methods, ideal for beginners and experienced bulk growers
- Filter patch bag and moisture balanced texture for healthy mycelium growth
- Made in USA with quality composted manure and coco coir base
Cons
- Exact supplement blend is proprietary, so you cannot adjust the recipe
- Requires separate colonized grain spawn, not an all in one grow kit
- Single 5 lb bag may not be enough for large monotubs or outdoor beds
The North Spore Boomr Bag is a 5 lb sterile bulk substrate built for dung loving mushroom species. It is made for beginners and experienced growers who want a ready to use base for monotubs, bags and outdoor beds.
The blend combines composted horse manure, coco coir and added supplements to support strong colonization and improved yields. Because it arrives sterile and hydrated to field capacity, you can mix it directly with colonized grain spawn without extra prep.
Built in a filter patch bag, it allows proper gas exchange while helping reduce contamination risk. The texture holds moisture well, and the USA made formula feels consistent, clean and professionally prepared.
The exact supplement blend is proprietary, so precise customization is limited. You will also need separate grain spawn, and larger projects may require multiple bags to fill big tubs or beds.
For growers who want reliable results without pasteurizing manure at home, the Boomr Bag is a practical upgrade. It saves time, simplifies spawn to bulk, and delivers a trusted foundation for productive grows.
Brand: North Spore, Style: Sterile substrate in filter patch bag.
Size: 5 pounds, 80 ounce count, 4.75 liters volume.
Material: Composted horse manure, coco coir plus substrate supplements, hydrated to field capacity.
Best for: Monotubs, filter bags, trays, Martha setups and outdoor beds for dung loving species.
Recommended use: Mix 1 colonized grain spawn bag with 2 to 3 Boomr Bags.
Mix one fully colonized grain spawn bag with two to three Boomr Bags for reliable colonization. Break up the spawn, blend evenly, then incubate in your monotub, bag or tray.
Maintain proper humidity and fresh air exchange for your chosen setup. For outdoor beds, layer the mix in a shaded spot and keep it moist but not waterlogged.
This substrate is best for dung loving species. If you are new to bulk growing, start with one tub to learn the process before scaling up.
Pros
- Professionally sterilized for a clean, contamination resistant start
- Dual phase nutrition from triple grain plus mineral enriched CVG
- Durable filter patch bag balances airflow and sterility
- Compact 2 lb size is easy to store, handle and learn with
Cons
- 2 lb capacity produces smaller harvests than larger bulk bags
- Requires separate mushroom culture and careful sterile technique
- Single bag format offers less value for growers running multiple projects
The SPAWN DADDY 2 lb All-in-One Grow Bag is a ready to use cultivation system that pairs sterilized grain with bulk substrate in one pouch. It is built for beginners, hobby growers, educators and gourmet cooks who want a simple start without mixing or sterilizing at home.
The triple grain blend of Red Milo sorghum, oats and rye berries gives mycelium multiple nutrient sources for vigorous colonization. Once colonized, the CVG layer of coco coir, vermiculite and gypsum boosted with Azomite micronutrients supports healthy fruiting for manure loving and gourmet varieties.
Each bag arrives professionally sterilized with a durable filter patch that allows gas exchange while blocking contaminants. The layered layout keeps grain and substrate separated until you are ready to mix, which helps reduce handling and contamination risk.
The 2 pound size is compact and easy to manage, but it naturally limits total yield compared to larger bulk setups. You will also need to supply your own sterile culture and practice clean inoculation technique, as success still depends on proper handling.
For home growers who value convenience, sterility and balanced nutrition, this bag offers a practical plug and play solution. It simplifies the process from inoculation to fruiting while delivering professional grade components in a beginner friendly format.
Brand: SPAWN DADDY, Model: Manlov, Size: 2 pounds, Single pack all-in-one grow bag for mushrooms.
Grain Layer: Red Milo sorghum, oats and rye berries, professionally sterilized for strong colonization.
Substrate Layer: Coco coir, vermiculite, gypsum plus Azomite micronutrients for added nutrition.
Design: Filter patch bag for gas exchange, suited for gourmet, edible and manure loving mushrooms.
How They Compare
Ingredient Blend and Nutrient Load
North Spore ‘Boomr Bag’ Sterile Mushroom Bulk features a proprietary blend of composted horse manure, coco coir, and several quality substrate supplements, formulated by mycologists to increase yield for dung loving species. In contrast, 10 LBS Coco Mushroom Substrate with Added Cow lists a transparent CVG plus manure recipe of Coco Coir, Cow Manure, Vermiculite, and Gypsum, fortified with nutrients to carry mycelium from spawn run through to fruiting mushrooms.
The Boomr approach offers a refined horse manure base that growers commonly report supports vigorous colonization and strong second flushes, but the exact supplement ratio stays secret which is a real drawback if you like to replicate or tweak recipes at home. The cow manure CVG is explicit and beginner friendly with clear components for moisture retention and aeration, though manure adds odor and a richer nutrient load that demands careful spawn ratios and clean handling to keep colonization even across the full bag.
Bag Size, Hydration and Batch Planning
Size is the clearest split between these two sterilized bags. North Spore ‘Boomr Bag’ Sterile Mushroom Bulk comes as a 5 lb bag hydrated to field capacity, while 10 LBS Coco Mushroom Substrate with Added Cow arrives as a 10 LB pre hydrated bag in a 0.2 micron filter bag. Both are ready to use right out of the bag, so you avoid measuring vermiculite or soaking coir, and you can explore our bulk substrate library to match weight to your tub volume and spawn inventory.
For planning, the 5 lb format suits single monotubs, trays or humidity controlled Martha setups and makes it easy to split a run across multiple bags so one slow bag does not stall the whole project. The 10 LB format suits larger monotubs or growers who want to fill in one pour without opening multiple bags, but that single bag is heavier to break up and mix evenly, and losing it to contamination costs more substrate at once, so weigh convenience against risk spreading.
Sterility System and Ease of Use Workflow
North Spore ‘Boomr Bag’ Sterile Mushroom Bulk is sold as a sterile manure based bulk substrate, trusted by growers over several seasons and designed for monotubs, filter bags, outdoor beds, or fruiting from the bag or tray in a humidity controlled room. 10 LBS Coco Mushroom Substrate with Added Cow is sold as a sterilized fruiting bag that gives spawned grain a clean environment without competition from foreign outside growth, with a 0.2 micron bag that supports gas exchange while limiting airborne contaminants.
In practice, both let you dump substrate into a monotub for bulk or dump a grain bag into the substrate bag for grow in the bag fruiting, which keeps prep minimal for beginners. Boomr Bag flexibility for outdoor beds and trays is helpful if you run varied setups or want to fruit outside of a tub, while the SGM LABS workflow is deliberately simple for first time growers, hobbyists or bulk cultivators who want casing use, monotub fill or in bag growth without extra hydration steps. Neither option removes the need for sterile grain handling and careful inoculation technique.
Track Record, Ratings and Grower Guidance
On reputation, 10 LBS Coco Mushroom Substrate with Added Cow is rated 4.5/5 from 132 reviews, which gives new buyers a larger pool of shared outcomes to review for consistency, moisture level and handling. North Spore ‘Boomr Bag’ Sterile Mushroom Bulk is rated 4.2/5 with 0 reviews in the provided data, so you lean more on brand history than on recent buyer volume, since Boomr Bag has been perfected for dung loving species and is widely trusted by mushroom growers for reliable bulk performance.
Guidance also differs in precision and tone. North Spore recommends mixing 1 colonized grain spawn bag with 2 to 3 Boomr Bags and notes that higher inoculation rates might improve success, plus the brand recommends 1 lb of colonized grain spawn for every 5 lbs of manure or hardwood sterile substrate on its grain bags, with 2.5 to 5ccs per 3 lb injection port bag. SGM LABS keeps it broad, positioning its substrate for first time growers through large scale cultivators with a simple dump and mix method, which is reassuring but less precise if you like exact spawn to bulk math. More background is in our CVG and bulk amendments collection to help you plan ratios.
Which One Should You Get
Choose North Spore ‘Boomr Bag’ Sterile Mushroom Bulk if you run small to mid size monotubs, trays or a Martha setup and prefer a composted horse manure, coco coir and supplement blend made for dung loving varieties. It is the better fit when you want flexibility for indoor tubs, filter bags or outdoor beds, you plan to run 2 to 3 bags per spawn bag for a balanced inoculation rate, and you value a mycologist formulated recipe with long brand history over a fully disclosed ingredient list.
Choose 10 LBS Coco Mushroom Substrate with Added Cow if you want maximum volume in one purchase for large monotubs or back to back runs and prefer an explicit Coco Coir, Cow Manure, Vermiculite, and Gypsum blend. It is the better fit for beginners who want a ready to use, pre hydrated 10 LB bag with straightforward dump into monotub or grow in the bag instructions, plus the reassurance of 132 buyer ratings to help set expectations for moisture, mixing effort and bulk yield potential.
Who Should Skip Both
Both manure enriched bags are not ideal for growers who want a plain, low odor CVG without animal inputs, for micro batches where a 5 lb or 10 LB bag is too much to use at once, or for anyone who prefers to hydrate and condition bulk by hand for full recipe control. If you only need spawn, consider North Spore Organic Sterilized Mushroom Grain Bag, if you want plain coir based bulk look at CVG Substrate (5 lb) – Pre-Sterilized Coco Coir or 5 LBS Black Coco Mushroom Substrate, and if you want grain plus substrate together the SPAWN DADDY™ 2 lb All-in-One Mushroom Grow Bag follows a different all in one path.
Frequently Asked Questions
Can I fruit directly in the sterilized substrate bag instead of using a monotub?
Yes, both bags support it when humidity is managed. North Spore ‘Boomr Bag’ Sterile Mushroom Bulk can be grown from the bag or tray in a humidity controlled grow room or Martha setup, and 10 LBS Coco Mushroom Substrate with Added Cow can be used to grow in the bag by adding grain directly to the CVG bag. Growers commonly report better airflow and more even flushes in a monotub, so use in bag fruiting when space is tight and move to a tub for larger canopy coverage.
How much grain spawn do I need for a 5 lb or 10 lb manure substrate bag?
For North Spore ‘Boomr Bag’ Sterile Mushroom Bulk, the brand recommends mixing 1 colonized grain spawn bag with 2 to 3 Boomr Bags and notes higher inoculation rates might improve results. For manure or hardwood sterile substrate in general, North Spore also recommends 1 lb of colonized grain spawn for every 5 lbs of substrate, with 2.5 to 5ccs per 3 lb injection port bag on its grain bags. With 10 LBS Coco Mushroom Substrate with Added Cow, plan on roughly double the spawn you would use for a single 5 lb bag and mix thoroughly for even colonization.
Is cow manure or horse manure substrate better for dung loving mushrooms?
Both can work well when properly composted, sterilized and hydrated to field capacity. Composted horse manure blends like North Spore ‘Boomr Bag’ Sterile Mushroom Bulk are formulated specifically for dung loving species and include coco coir plus supplements for structure and moisture retention. Cow manure CVG like 10 LBS Coco Mushroom Substrate with Added Cow pairs manure with Coco Coir, Vermiculite, and Gypsum for nutrition plus aeration, which many beginners find forgiving in monotubs.
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