{"product_id":"blue-oyster-colonized-grain-spawn-bag-5-lb","title":"Blue Oyster Colonized Grain Spawn Bag 5 LB","description":"\u003cstyle\u003e.mgk-product-content .b { font-weight:600 !important; }\u003c\/style\u003e\n\u003cdiv class=\"mgk-product-content\"\u003e\n\u003cp\u003e\u003cspan class=\"b\"\u003eFully colonized Blue Oyster (\u003cem\u003ePleurotus ostreatus\u003c\/em\u003e) grain spawn, 5 LB\u003c\/span\u003e, grown on our millet-based grain blend in a filtered Unicorn 3T bag. Built on premium first-generation genetics and produced fresh at our Illinois lab — fully colonized before it ships and ready to break up and inoculate the moment it arrives. Blue Oyster is one of the fastest, most aggressive colonizers you can grow, with striking blue-grey caps that lighten to silvery tan as they fruit — forgiving, high-yielding, and a favorite of commercial growers and first-timers alike.\u003c\/p\u003e\n\u003cdiv class=\"mgk-callout mgk-callout-ships\"\u003e\n\u003cspan class=\"b\"\u003e✓ Made Fresh — Ships Same or Next Business Day\u003c\/span\u003e\u003cbr\u003eWe don't stockpile spawn on a shelf for months. Bags are produced on a rolling schedule and held fully colonized, then shipped fresh. \u003c\/div\u003e\n\u003cdiv class=\"mgk-callout mgk-callout-ships\"\u003e\u003c\/div\u003e\n\u003ch3\u003ePremium Genetics, Sourced Worldwide\u003c\/h3\u003e\n\u003cp\u003eStrong genetics are the difference between a reliable commercial run and a disappointing one — so we built our library from the best sources we could find. Our Blue Oyster spawn starts with our own in-house master culture collection at Myco Labs, refined over years of isolation work, and is expanded through a partnership with \u003cspan class=\"b\"\u003eone of the largest commercial culture suppliers in Canada\u003c\/span\u003e, along with select strains sourced from the \u003cspan class=\"b\"\u003eUK and Asia\u003c\/span\u003e. Every culture is held as first-generation commercial genetics and selected for vigorous, clean colonization and true-to-type fruiting. This is the genetic foundation serious cultivators build a farm on.\u003c\/p\u003e\n\u003ch3\u003eWhat You'll Receive\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan class=\"b\"\u003e5 LB of fully colonized grain spawn\u003c\/span\u003e — premium first-gen Blue Oyster (bags are filled generously and typically weigh in above 5 LB)\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"b\"\u003eMillet-based grain blend\u003c\/span\u003e — primarily white and red millet with a small amount of milo; the fine grain gives plenty of inoculation points for fast, even colonization\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"b\"\u003eUnicorn 10T bag\u003c\/span\u003e with a 0.22-micron filter patch and self-healing injection port\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"b\"\u003e3-mil construction\u003c\/span\u003e, sterilized in a 3-hour autoclave cycle\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"b\"\u003eLab-inspected\u003c\/span\u003e for contamination and produced fresh at Myco Labs (Illinois, USA)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHow to Use Your Grain Spawn\u003c\/h3\u003e\n\u003cp\u003eThese bags are made to be broken up and mixed directly into sterilized bulk substrate. The most popular method is Master's Mix block production:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan class=\"b\"\u003eMix into Master's Mix\u003c\/span\u003e — break up the colonized grain and combine it with our \u003ca href=\"https:\/\/www.midwestgrowkits.com\/products\/sterilized-masters-mix-bag-5-lbs\"\u003e5 LB Sterilized Master's Mix\u003c\/a\u003e. One 5 LB bag inoculates 12–13 Master's Mix bags. Step-by-step walkthrough here: \u003ca href=\"https:\/\/www.midwestgrowkits.com\/blogs\/blog-1-growing-101-more\/how-to-use-grain-spawn-with-master-s-mix-substrate\"\u003eHow to Use Grain Spawn with Master's Mix Substrate\u003c\/a\u003e.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"b\"\u003eExpand to more grain\u003c\/span\u003e — use a portion to inoculate additional sterilized grain (a grain-to-grain transfer) and multiply your spawn before spawning to bulk\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"b\"\u003eSpawn a monotub or bulk bed\u003c\/span\u003e — mix into any properly prepared pasteurized or sterilized bulk substrate\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eFor grain-to-grain transfers or any open work, do it in front of a \u003ca href=\"https:\/\/www.midwestgrowkits.com\/collections\/flow-hoods-clean-room\"\u003elaminar flow hood or clean-room setup\u003c\/a\u003e. A few minutes under HEPA-filtered air keeps contamination out and dramatically improves your success rate — especially when you're expanding spawn rather than going straight to a sealed Master's Mix bag.\u003c\/p\u003e\n\u003ch3\u003eBlue Oyster Growing Characteristics\u003c\/h3\u003e\n\u003ctable class=\"mgk-spec-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eLatin name\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cem\u003ePleurotus ostreatus\u003c\/em\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eMycelium appearance\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003eWhite, fast, aggressive rhizomorphic growth\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eSpawn-to-substrate ratio\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e~1 part spawn to 3 parts substrate (one 5 LB bag → 12–13 Master's Mix bags)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003ePreferred substrate\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003eMaster's Mix, hardwood sawdust + bran, straw\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eFruiting temperature\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e55–65°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eDifficulty\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003eBeginner-friendly\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eUse category\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003eGourmet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eGrain Spawn Specifications\u003c\/h3\u003e\n\u003ctable class=\"mgk-spec-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eNet weight\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e5 LB advertised (typically fills to ~5.5 LB)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eGrain\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003ePrimarily white and red millet with a small amount of milo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eBag\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003eUnicorn 10T, 3-mil, 0.22-micron filter patch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eInjection port\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003eSelf-healing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eSterilization\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e3-hour autoclave cycle\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eSterility\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003eProduced under HEPA-filtered laminar flow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"b\"\u003eShelf life\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e90 days best \/ 120 days refrigerated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eSterility \u0026amp; Quality Standards\u003c\/h3\u003e\n\u003cp\u003eEvery bag is produced and inspected at Myco Labs under HEPA-filtered laminar flow, then incubated in a dedicated clean room until fully colonized. Each bag is visually inspected for contamination before it's approved for shipment. If it doesn't look right, it doesn't ship.\u003c\/p\u003e\n\u003ch3\u003eShipping \u0026amp; Handling\u003c\/h3\u003e\n\u003cp\u003eSpawn ships in padded packaging. In summer months (May–September) or to hot-climate destinations, we include a cold pack at no additional cost. Use your spawn promptly for best results; an unopened bag stays at peak viability for about 90 days at room temperature, or up to 120 days refrigerated at 35–40°F. Refrigerate if you're not using it right away.\u003c\/p\u003e\n\u003ch3\u003eRecommended Companion Products\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/www.midwestgrowkits.com\/products\/sterilized-masters-mix-bag-5-lbs\"\u003eSterilized Master's Mix (5 LB)\u003c\/a\u003e — the intended pairing; one spawn bag inoculates 12–13\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/www.midwestgrowkits.com\/collections\/flow-hoods-clean-room\"\u003eLaminar Flow Hoods \u0026amp; Clean Room Equipment\u003c\/a\u003e — for contamination-free grain transfers\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/www.midwestgrowkits.com\/collections\/liquid-culture-syringes\"\u003eLiquid Culture Syringes\u003c\/a\u003e — same genetics, ready-to-inject format\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/www.midwestgrowkits.com\/collections\/spawn-bags\"\u003eUninoculated Spawn Bags\u003c\/a\u003e — to colonize your own grain from culture\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cdetails class=\"mgk-faq\"\u003e\n\u003csummary\u003e\u003cspan class=\"b\"\u003eIs this ready to use, or do I need to colonize it?\u003c\/span\u003e\u003c\/summary\u003e\n\u003cp\u003eIt's fully colonized and ready to go. Break it up and mix it directly into sterilized Master's Mix or your bulk substrate of choice — no inoculation, sterilization, or colonization wait on your end.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails class=\"mgk-faq\"\u003e\n\u003csummary\u003e\u003cspan class=\"b\"\u003eHow many Master's Mix blocks will one 5 LB bag inoculate?\u003c\/span\u003e\u003c\/summary\u003e\n\u003cp\u003eOne 5 LB bag inoculates 12–13 of our 5 LB Sterilized Master's Mix bags at our recommended ratio, turning a single spawn bag into a full block run.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails class=\"mgk-faq\"\u003e\n\u003csummary\u003e\u003cspan class=\"b\"\u003eDo I need a flow hood to use this?\u003c\/span\u003e\u003c\/summary\u003e\n\u003cp\u003eNot for the simplest workflow — breaking the spawn into a freshly opened Master's Mix bag in a clean, still space works for many growers. But for grain-to-grain transfers or any extended open work, a laminar flow hood or clean-room setup with HEPA-filtered air significantly lowers contamination risk. We carry both in our \u003ca href=\"https:\/\/www.midwestgrowkits.com\/collections\/flow-hoods-clean-room\"\u003eflow hood and clean room collection\u003c\/a\u003e.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails class=\"mgk-faq\"\u003e\n\u003csummary\u003e\u003cspan class=\"b\"\u003eWhere do your genetics come from?\u003c\/span\u003e\u003c\/summary\u003e\n\u003cp\u003eOur cultures come from our own in-house master collection at Myco Labs, plus a partnership with one of the largest commercial culture suppliers in Canada and select strains sourced from the UK and Asia. Everything is maintained as first-generation commercial genetics and selected for vigor and true-to-type fruiting.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails class=\"mgk-faq\"\u003e\n\u003csummary\u003e\u003cspan class=\"b\"\u003eHow fresh is it, and how long will it stay viable?\u003c\/span\u003e\u003c\/summary\u003e\n\u003cp\u003eEvery bag is made fresh at our Illinois lab — never stockpiled for months. An unopened bag stays at peak viability for about 90 days at room temperature, or up to 120 days refrigerated. Refrigerate if you're not using it right away.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails class=\"mgk-faq\"\u003e\n\u003csummary\u003e\u003cspan class=\"b\"\u003eCan I use this in a monotub instead of Master's Mix blocks?\u003c\/span\u003e\u003c\/summary\u003e\n\u003cp\u003eYes. While these are built for breaking up into sterilized Master's Mix, the colonized grain can be mixed into any properly prepared bulk substrate, including a monotub.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails class=\"mgk-faq\"\u003e\n\u003csummary\u003e\u003cspan class=\"b\"\u003eWhat if my bag arrives contaminated or damaged?\u003c\/span\u003e\u003c\/summary\u003e\n\u003cp\u003eWe guarantee every bag ships fully colonized and contamination-free. If you receive a contaminated or damaged bag, contact us within 5 days of delivery with a photo and we'll replace it free of charge.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e","brand":"Midwest Grow Kits","offers":[{"title":"Default Title","offer_id":47406212579477,"sku":"BOGS","price":24.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0712\/0679\/7461\/files\/Blue_oyster_grain_spawn.jpg?v=1780513419","url":"https:\/\/www.midwestgrowkits.com\/products\/blue-oyster-colonized-grain-spawn-bag-5-lb","provider":"Midwest Grow Kits","version":"1.0","type":"link"}