# Best sterile mushroom substrate bags: masters mix, hardwood and CVG Source: https://spawnrun.com/best/best-mushroom-substrate-bags Publisher: Spawn Run. Picks are chosen from what each Amazon listing states, not from hands-on tests. Method: https://spawnrun.com/how-we-pick A substrate bag is a filter patch bag that arrives already filled, hydrated and sterilized, so you skip the pressure cooker and go straight to mixing in colonized grain spawn. The recipe inside decides what you can grow. Wood-loving species such as oyster, lion's mane, shiitake, pioppino and chestnut want hardwood sawdust, ideally supplemented with soy hulls in the 50/50 masters mix. CVG (coco coir, vermiculite and gypsum) and manure-based blends are for compost and dung-loving species, and an oyster or lion's mane spawned into CVG will struggle. Other things to compare are weight per bag (5 lb is standard and takes about 1 lb of grain spawn), whether the listing says sterilized or pasteurized, the filter rating and storage life. This guide covers wood-based bags, CVG and manure bulk bags, and an all-in-one bag with grain and substrate in one. ## Picks ### 1. North Spore Organic 'Wood Lovr' Sterile Hardwood Mushroom Substrate, 5 lbs North Spore Wood Lovr: 5 lb of autoclave-sterilized hardwood chips and sawdust with nitrogen supplement, for wood-loving species in bags, monotubs, trays or buckets. What the listing offers: - Mix of chip and sawdust particle sizes, which helps air move through the block - Sterility verified with biological indicators and temperature sensors, per the listing - States a 1 lb grain spawn to 5 lb substrate rate and room temperature storage for several months Limits to know: - Costs about 10 dollars more than the masters mix bags for the same 5 lb - Listing names a nitrogen supplement but not what it is, unlike the 50/50 soy hull blends ### 2. North Spore 'Mastr Mix' Sterile Soyhull & Hardwood Bulk Substrate, 5 lbs North Spore 5 lb bag of soy hull and hardwood bulk substrate, a proprietary masters mix style blend for oyster, shiitake, maitake, pioppino, king trumpet and chestnut. What the listing offers: - Soy hull and hardwood blend is the standard high-yield recipe for wood-loving gourmet species - Listing names a wide range of suitable species, including shiitake and king trumpet - Every batch is bacterial load tested before shipping, according to the listing Limits to know: - Product title says sterile but the feature bullets say pasteurized, so treat it with extra care and use it promptly - Single 5 lb bag, enough for one block or a small tub ### 3. Sterilized Master’s Mix Mushroom Substrate 5 LB Bag - 50/50 Oak Hardwood Pellets & Non-GMO Soy Hulls - Prepped & Ready for Gourmet Mushroom Cultivation-Ideal for Oyster, Lion’s Mane, Chestnut & More Spore Sorcery 5 lb masters mix: a 50/50 blend of oak hardwood pellets and non-GMO soy hulls, sterilized in a bag with a 0.5 micron filter patch, for oyster, lion's mane and chestnut. What the listing offers: - Classic 50/50 hardwood and soy hull ratio stated plainly in the listing - Oak pellet base, a hardwood that most wood-loving species colonize well - Larger 0.5 micron filter patch for gas exchange during colonization Limits to know: - Smaller brand than North Spore, with less detail on how sterility is checked - Listing does not give a storage time before use ### 4. North Spore CVG Mushroom Growing Substrate, Sterilized Bulk, 1 Pack North Spore sterile CVG bulk substrate, pre-hydrated to field capacity and autoclaved. Low-nutrient coco coir, vermiculite and gypsum mix for monotubs and dung-loving species. What the listing offers: - Low nitrogen recipe that the listing presents as more resistant to contamination than richer substrates - Ingredients named and batch-tested, including RHP-certified coco coir and asbestos-free vermiculite - States a mix rate of one grain bag to 2 to 4 bags of CVG Limits to know: - Not a substrate for oyster, lion's mane or shiitake, which need wood - Listing does not state the bag weight in the feature bullets ### 5. Wood-Based Mushroom Substrate (5lb) Out-Grow 5 lb bag of sterilized hardwood sawdust with gypsum and reverse osmosis water, for shiitake, lion's mane, oyster and other wood-loving species. What the listing offers: - Simple hardwood sawdust and gypsum recipe, a good match for shiitake and lion's mane - Ships sealed in a filter patch grow bag, ready to inoculate - Lowest priced of the 5 lb wood-based bags here Limits to know: - No soy hull supplement, so yields will be lower than a masters mix - Listing gives the filter as 5 micron, coarser than the 0.2 to 0.5 micron patches common on grow bags ### 6. SPORE SORCERY 6 LB All-in-One Mushroom Grow Bag - Sterilized Substrate, Injection Port - Up to 48oz Yield - Culture Not Included Spore Sorcery 6 lb all-in-one bag: sterilized milo grain layered over CVG bulk substrate with a self-healing injection port, so one bag colonizes and fruits without a transfer. What the listing offers: - Grain and bulk substrate in one sealed bag, no spawning step and no monotub needed - Double bagged and vacuum sealed for shipping, with a 0.5 micron filter patch - Self-healing injection port for adding liquid culture Limits to know: - CVG bulk layer limits it to dung-loving species - Needs a liquid culture or spore syringe, which is not included ### 7. North Spore Boomr Bag Sterile Mushroom Substrate, Manure-Based, 5 lb North Spore Boomr Bag: 5 lb of sterile composted horse manure, coco coir and supplements for dung and compost-loving species, used in monotubs, grow bags, trays or outdoor beds. What the listing offers: - Composted manure base suits compost-loving species better than plain CVG - Autoclave sterilized and checked with biological indicators, per the listing - Stores at room temperature for several months, and the listing recommends 1 grain bag to 2 or 3 Boomr Bags Limits to know: - Wrong substrate for wood-loving gourmet species - Most expensive per pound of the bulk bags here As an Amazon Associate I earn from qualifying purchases.